Search

Thirteen species of Polytrichaceae belonging to seven genera are hereby reported from Brazil: Atrichum androgynum, Itatiella ulei, Notoligotrichum minimum, Oligotrichum canaliculatum, O. denudatum, O. riedelianum, Pogonatum campylocarpum, P. pensilvanicum, P. perichaetiale subsp. oligodus, Polytrichadelphus pseudopolytrichum, Polytrichum angustifolium, P. commune and P. juniperinum. Polytrichadelphus organensis and Polytrichum reflexifolium are placed in synonymy with Polytrichum juniperinum, Polytrichum brasiliense with P. angustifolium and P. subremotifolium with P. commune. Keys, descriptions and illustrations are presented for all species.

Except for Sphagnum mosses of peatland habitats, reliable methods to assess moss productivity in arctic or boreal biomes give usually highly variable results. Therefore, ecosystem processes are poorly understood in these biomes where mosses are an important component of the system. The aim of this study was to compare three methods to estimate moss growth in polygon patterned fens: cranked wires, natural markers and artificial white marks (an alternative to the spray method). Precision of estimates was significantly higher when natural markers were used (coefficients of variation, CV, between 17 and 27%), compared to cranked wires (CV = 37%) or white marks (CV = 56%). Natural markers also provided estimates for growth of moss stems 32 to 113% higher than the other methods. Although cranked wires were calibrated shortly after snowmelt, some moss growth is still missed and consequently moss growth is underestimated. Accuracy of cranked wires was poor, mainly caused by frost heaving or permafrost ac...

We used horizontal starch-gel electrophoresis to examine genetic similarities among 24 species of the Polytrichaceae. Mean genetic identity between species ranged from 0.281 to 0.998. Species of Oligotrichum and Pogonatum were genetically similar to their congeners and clearly differentiated from the other taxa. Species that have traditionally been placed in Polytrichum on the basis of their morphological characters were separated genetically into three groups. The first two groups included taxa commonly recognized in Polytrichum sect. Polytrichum and sect. Juniperifolia. The third group consisted of some, but not all, of the taxa sometimes placed in the segregate genus Polytrichastrum. A duplicated locus in all species of Polytrichum sensu stricto supports the uniqueness of this group vis-a-vis Polytrichastrum and other taxa. Polytrichastrum alpinum, the type species for the genus, was quite dissimilar genetically from other taxa commonly placed in the genus. This was also true for P. sexangulare, which showed high genetic affinity to a morphologically similar taxon commonly placed in Pogonatum. The Polytrichaceae are a relatively small family of mosses comprised of 19 genera and ca 200 species (Hyv6nen et al. 1998). Several species, such as Polytrichum commune and P. juniperinum (authorities are listed in Table 2), are familiar to many researchers due to their robust size and nearly cosmopolitan occurrence in the Northern Hemisphere. These and other species of the Polytrichaceae have been used extensively in a variety of studies. Investigations of their population biology, recently reviewed by Wyatt and Derda (1997), have contributed significantly to our understanding of several ecological and genetic phenomena in bryophytes. Historically, the taxonomy of the hair-cap mosses (subclass Polytrichidae) has been problematical at all hierarchical levels (Wyatt & Derda 1997). Most troublesome has been the placement of several species traditionally placed in Polytrichum and Pogonatum (Table 1). Many of these display morphological characters that cross the boundaries of both traditional and recently proposed genera (Merrill 1992). Several authors (e.g., Crum & Anderson 1981; Lawton 1971; Osada 1966) have followed the traditional taxonomic treatment of Frye (1937), who split Polytrichum from Pogonatum solely on the basis of terete versus angled capsules (Merrill 1992). Nevertheless, even authors who have used this simple approach have admitted that the division is unnatural and that there remain taxa that are difficult to place (e.g., P. alpinum). In a re-evaluation of generic concepts in the Polytrichaceae, Smith (1971) proposed the division of Polytrichum sensu lato into Polytrichastrum and Polytrichum sensu stricto. This was done on the basis of the pterygodont peristome, membranous and persistent epiphragm, and knife-edged, four-angled capsule in Polytrichum. In contrast, species of Polytrichastrum possess a leiodont peristome, a thick and deciduous epiphragm, and a capsule geometry that is either terete or with 4-6 rounded angles (Merrill 1992). Smith's (1971) concepts were adopted in a checklist of Fennoscandian mosses by Koponen et al. (1977), but Anderson et al. (1990) in their recent checklist of the mosses of North America chose to recognize Polytrichastrum in a new sense, including only the type speciesP. alpinum-in that genus. The problematical species under examination in this study and their generic placement by different authors (Anderson et al. 1990; Frye 1937; Koponen et al. 1977; Merrill 1992) are presented in Table 1. The treatment by Merrill (1992) as presented here differs from an earlier treatment (Smith 1971) only in the recognition of a new genus, Meiotrichum, to accommodate M. lyallii. Most evident in the table is the division of Polytrichum sensu lato, with the same taxa assigned to the segregate genera (Poly0007-2745/99/352-365$1.55/0 This content downloaded from 207.46.13.124 on Wed, 22 Jun 2016 05:26:45 UTC All use subject to http://about.jstor.org/terms 1999] DERDA ET AL.: POLYTRICHACEAE 353 TABLE 1. Four taxonomic treatments of "problematic" taxa of Polytrichaceae considered in this study. Polytrichum lyallii is separated from other members of the genus under "Anderson et al. 1990" in order to maintain horizontal alignment of the species. NR = not recognized taxonomically; OR = outside the range of the taxon. Fry 1937 Merrill 1992 Koponen et al. 1977 Anderson et al. 1990 Polytrichum Polytrichum Polytrichum Polytrichum commune commune commune commune var. jensenii NR jensenii var. jensenii juniperinum juniperinum juniperinum juniperinum var. alpestre strictum strictum strictum piliferum piliferum piliferum piliferum var. hyperboreum hyperboreum hyperboreum hyperboreum Polytrichastrum Polytrichastrum gracile longisetum longisetum longisetum formosum formosum formosum formosum NR pallidisetum pallidisetum pallidisetum obioense obioense OR ohioense NR appalachianum OR appalachianum norvegicum sexangulare sexangulare sexangulare

Phylogenetic analyses on Polytrichales were conducted using morphological characters as well as sequence data from the chloroplast genes rbcL and rps4 and the nuclear-encoded 18S rRNA gene. Our analyses included 22 species representing all genera of Polytrichales, plus eight outgroup species. Sequence data were obtained from 25, 22, and 19 taxa for 18S, rbcL and rps4 genes, respectively. Phylogenetic trees were constructed with parsimony analyses. Results lend support for recognition of Polytrichales as a distinct, monophyletic entity. After successively approximated weighting, Oedipodium griffithianum appears as the sister-group to Polytrichales. Within Polytrichales, Alophosia, Bartramiopsis, and Lyellia have the most basal placement outside a clade including all other genera. Atrichopsis, Dendroligotrichum, Itatiella, Meiotrichum, and Notoligotrichum are distinguished as a resolved monophyletic group while other genera are left as an unresolved entity. Resolution between these genera is achieved by successive weighting of data. After this, Dawsonia is resolved in the basal position within the clade and Polytrichastrum appears as a sister-taxon to Eopolytrichum and Polytrichum. Polytrichales are typically pioneer plants of open, sometimes even dry, habitats. Despite comprising only a small number of species, the order exhibits great diversity of shapes and sizes, from miniature plants such as Pogonatum piliferum (Dozy & Molk.) Touw of SE Asia and P. pensilvanicum (Hedw.) P. Beauv. of E North America to giants of Papua New Guinea like Dawsonia gigantea Geh. with stems reaching up to 80 cm. The most typical features of Polytrichales are the adaxial leaf lamellae and differentiation of leaves into a distinct blade and sheathing base. The hairy calyptra has given the group its name, although most genera have practically naked calyptrae. Sporophytes of Polytrichales normally have a well-developed peristome with at least 16 teeth that consist of whole cells. The epiphragm that covers the mouth of the capsule is a unique character that distinguishes most of the genera from all other groups of mosses. Size and shape of the urn vary greatly among genera (Schofield 1985; Smith 1971). The number of currently accepted genera in the Polytrichales is 19, and the approximate number of species in each genus is given in Table 1. One genus, along with its sole species Eopolytrichum antiquum Konopka, Herendeen, Merrill & Crane, is known only from beautifully preserved late Cretaceous fossils that reveal its structures in fine detail (Konopka et al. 1997). Many of the remaining genera are monotypic and all the others, with the exception of Pogonatum and Polytrichum, are fairly small. Schofield (1985) gives a conservative estimate of about 370 for the number of species in Polytrichales, but on the basis of recent critical revisions (e.g., Hyvinen 1989) it is realistic to assume that the number is actually closer to, or even less than, 200. Some species, like Polytrichum juniperinum Hedw., are almost cosmopolitan, while others, like the Macaronesian Alophosia azorica (Ren. & Card.) Card., are narrow endemics and possibly 1 This paper was presented at the 1997 Montr6al ABLS symposium sponsored by the Green Plant Phylogeny Research Coordination Group (with funding provided by DOE/NSF/USDA Panel on Collaborative Research in Plant Biology, USDA grant 94-7105-0713, Co-Pls Mark A. Buchheim, Brent D. Mishler, Russell L. Chapman). 0007-2745/98/489-504$1.75/0 This content downloaded from 207.46.13.162 on Fri, 01 Jul 2016 05:45:45 UTC All use subject to http://about.jstor.org/terms 490 THE BRYOLOGIST [VOL. 101 TABLE 1. The approximate number of species in the genera of Polytrichales. t-fossil. Alophosia 1 Meiotrichum 1 Atrichopsis 1 Notoligotrichum 10 Atrichum 15 Oligotrichum 10 Bartramiopsis 1 Pogonatum 50 Dawsonia 10 Polytrichadelphus 10 Dendroligotrichum 2 Polytrichastrum 10 t Eopolytrichum 1 Polytrichum 30 Hebantia 1 Psilopilum 2 Itatiella 1 Steereobryon 1 Lyellia 4 even threatened by extinction. Ecologically, the Polytrichales range from xerophytes like Polytrichum piliferum Hedw. to species of peaty, wet habitats like P. commune Hedw. Although their structure appears so obviously adapted to dry environments, the Polytrichales are largely absent from extremely arid regions, and the group exhibits greatest diversity in areas with humid or moist climates like SE Asia and Central America-northern South America. Phylogenetic relationships of the Polytrichales are particularly relevant to considerations of moss evolutionary history since the group is probably among the first of the lineages that diverged from the common ancestor of all mosses (Mishler & Churchill 1984). Smith (1971) presented a dendrogram with assumed phylogenetic trends for Polytrichales, and these ideas were further developed in his study of epiphragm structure and spore ornamentation (Smith 1974). Hyv6nen (1989), in a revision of Pogonatum that included cladistic analysis based on manual Hennigian argumentation, tentatively distinguished three entities in the Polytrichales as an unresolved basal trichotomy. These, and many other authors, viewed Polytrichastrum G. L. Sm. as the closest extant approximation to the common ancestor of Polytrichales. Forrest (1995) presented the first computer-aided analyses of Polytrichalean phylogeny based on a matrix of 50 characters compiled from the literature. The cladogram from her successively weighted analysis of these data is presented in Figure 1 (fig. 3b in Forrest 1995). In contrast to the views noted above, the position of Atrichum as sister to the remaining Polytrichales suggests that relatively simple members of the group more closely approximate the ancestral condition. This is congruent with ideas presented previously by Fleischer (1923). Forrest's (1995) analyses resolved both strongly and weakly supported groups as implied by the number of characters supporting each clade. To test the strength of the phylogenetic hypotheses based on morphology and to determine whether they are congruent with other sources of data we explored Tetraphis

Polytrichastrum sect. Meiotrichum G. Sm. is raised to generic rank, with one species: Meiotrichum lyallii (Mitt.) Merr. Polytrichastrum sect. Aporotheca (Limpr.) Merr., Polytrichastrum appalachianum (Anders.) Merr., and Polytrichastrum sexangulare var. vulcanicum (C. Jens.) Merr. are new combinations. The diagnostic features of Polytrichum, Polytrichastrum, and Pogonatum are given, with an explanation of the generic concepts.

Twenty-six families, 67 genera, 145 species, and four varieties of mosses are reported from Lassen Volcanic National Park, California. Two species, Andreaea nivalis Hook. and Polytrichum sexangulare Brid., are new to California. Mielichhoferia tehamensis Showers, a recently described species, is endemic to the Lassen Park region. Lassen Volcanic National Park is located in northeastern California on the crest of the southern Cascade Range at approximately 40'30'N, 121'25'W. The elevational range within the park is about 1600 m, with the lowest point, 1590 m, in Warner Valley and the highest point, 3186 m, at the summit of Lassen Peak. Included in the park are 43,000 hectares of forests, subalpine meadows, volcanic cones, and lava flows of recent origin. From 1914 until 1921 a series of volcanic eruptions from Lassen Peak caused considerable damage to surrounding areas and created a six km2 devastated area. During the Pleistocene, the Lassen Park region experienced extensive glacial activity. Mount Tehama, an ancient composite volcano, dominated the southwestern part of the Park area prior to the formation of Lassen Peak. It once stood over 3500 m before it was deeply carved by glaciers. More than 610 m of elevation of the summit have disappeared because of subsidence and glacial scouring. Glacial polish and erratics, and the typical U-shaped valleys of Warner Valley and Blue Lake Canyon provide further evidence of past glacial activity. The climate of northern California and Lassen Volcanic National Park is characterized by cool, moist winters and, in general, warm, dry summers. Little precipitation falls during the summer months when hot, dry winds blow from the Sacramento Valley. At Manzanita Lake, at 1783 m, average yearly precipitation is 196 cm with 85% falling between October and April. Winter storms produce a deep snow cover throughout the Park. Snows above 2135 m remain until summer with some alpine lakes staying frozen until late July. The designation of plant communities within Lassen Volcanic National Park corresponds to those described by Munz and Keck (1959) as follows: Yellow Pine Forest (Pinus ponderosa Dougl., P. jeffreyi Grev. & Balf., and Abies concolor (Gord. & Glend.) Lindl.); Red Fir Forest (Abies magnifica Murr. and Pinus monticola Don); Subalpine Forest (Pinus albicaulis Engel., P. contorta var. murrayana (Grev. & Balf.) Critchf., and Tsuga mertensiana (Bong.) Carr.); and Alpine Fell Fields. Mosses are poorly represented both on the forest floor and as epiphytes on hardwoods and conifers. Because of the availability of moisture, the greatest diversity of moss species occurs in and around seepages, meadows, and the banks of streams. Mosses are uncommon to rare in much of the Park above 2700 m. The recent volcanic activity, the unstable volcanic ash, and the extremes of climate may account for this paucity. Although Lassen Volcanic National Park is situated in close proximity to the Sierra Nevada, many elements of its vascular plant flora (Gillett et al. 1961) and moss flora are allied to the Cascade Range of Oregon and Washington. Both Andreaea nivalis Hook. and Polytrichum sexangulare Brid. are reported here as new to California. They grow in similar habitats on cool, shaded, north-facing rocks and on soil 007-2745/82/324-328$0.65/0 This content downloaded from 157.55.39.96 on Mon, 18 Apr 2016 08:47:56 UTC All use subject to http://about.jstor.org/terms 1982] SHOWERS: MOSSES OF LASSEN PARK 325 over rock where snow remains until late in the season. Neither species occurs farther south than Lassen Park and both possess a more northerly distribution across North America into Europe in mountainous regions. Collections of mosses were made over several summers from 1974 to 1980 while the author was a ranger-naturalist at Lassen Volanic National Park. Voucher specimens are deposited in the herbarium at San Francisco State University (sFsu). Duplicate specimens are housed in the herbarium at the headquarters of Lassen Volcanic National Park, Mineral, California. Nomenclature conforms largely to Crum, Steere and Anderson (1973). One representative specimen of each taxon is cited by the author's collection numbers in the text. This work is in partial fulfillment of a Master of Arts Degree at San Francisco

The thickened lateral walls of the hydroids of Dendroligotrichum are morphologically and histochemically distinct from the hydrolyzed end walls. The evidence presented indicates the existence of encrusting materials in the thickened lateral walls. Controversy exists as to whether or not these encrusting compounds are lignins. Histochemical evidence at both the light and electron microscope level demonstrates the phenolic nature of these compounds. In a continuing study of the anatomy of certain polytrichaceous mosses, the first paper in this series (Scheirer, 1972) reported on the general anatomical complexity of the gametophore of Dendroligotrichum. A subsequent paper (Scheirer, 1973) extended these initial observations to the ultrastructural level. Both papers concluded that the lat- eral walls of the hydroids (water-conducting cells) are encrusted with deposits of lignin or a lignin-like substance. Additionally, the latter paper stressed the similarities that exist between hydroids of Dendroligotrichum and tracheary elements of vascular plants. Characterization of such encrusting materials in the water-conducting cells of an extant moss is of considerable importance in the study of the origin of bryophytes and vascular land plants and the relationship between tracheary elements and the process of lignification. For instance, the view (summarized by Schuster, 1966) that bryophytes and lower vascular plants evolved from a common ancestral "prototracheophyte" which possessed conducting tissues in both gametophyte and sporophyte is attractive because it has the merit of being supported by an ever increasing amount of data (H6bant, 1970). Controversy exists as to whether lignin or lignin-like compounds are found in cell walls of certain mosses. Siegel (1969) presented evidence for the presence of lignin in gametophores of two "giant" mosses (Dawsonia sp. and Dendroligotrichum sp.) native to New Zealand, while negative results were obtained for such genera as Polytrichum

Nineteen moss species are new to Oregon. Bruchia bolanderi Lesq., Encalypta brevicolla (B.S.G.) Bruch ex Angstr., Entosthodon leibergii Britt., Ephemerum crassinervium (Schwaegr.) Hampe, Ephemerum serratum (Hedw.) Hampe, Pohlia lescuriana (Sull.) Grout, Polytrichum sphaerothecium (Besch.) C. Muell. and Trematodon boasii Schof. occur here as noteworthy disjunctions. Recent collecting of mosses in Oregon has produced 19 species not previously reported from the state, judged from ranges of those taxa given by Lawton (1971). To the author's knowledge, occurrence of these species in Oregon has not been reported previously in the literature. Eleven of these records are expected range extensions that fill voids suggested by the presence of the species in neighboring states. Eight of the records are rare in the Pacific Northwest or are notable disjuncts from known populations in other regions of North America.

In a growing antheridium of Polytrichum, walls of the androgonial cells are conventional, except for frequent interruptions due to protoplasmic connections, which are larger than plasmadesmata, between adjacent androgones. Prior to final division, protoplasts round up because of thickening of the walls at the corners of cells. Dictyosomes seem to be important in secretion of wall materials. After the last division the thick walls take on a reticulate, and then alveolar, appearance in sectional views as the walls become the intercellular matrix. Each of the developing androcytes deposits a uniform granular wall layer against the alveolar matrix. The granular layer becomes the vesicle in which a sperm is released. In addition, an irregular granular-fibrillar layer is deposited within the vesicle. At maturity numerous sperm vesicles of a sperm mass are embedded in a continuous phase of lipid droplets. Lipids replace the thick walls that were present when androcytes were first differentiated. Wall developments are part of the preparation of the sperms for dispersal, and, as such, they are a crucial aspect of sperm maturation. Cell walls and associated space around a protoplast are thought to be greatly affected by activities of various components of the protoplast. For example, dictyosomes are in a state of rapid turnover in some plant cells, which exhibit a flow of membranes and secretions, via vesicles, to the plasma membrane, the cell wall and the extra-cellular space (Morr6 & Mollenhauer, 1974). Multivesicular bodies (Schulz & Lehmann, 1970) and various types of paramural bodies (Berlyn, 1970) also appear to be involved in addition of materials to cell walls. This paper correlates protoplasmic changes with the changing nature of the walls and associated spaces around each spermatogenous cell during spermatogenesis in the moss Polytrichum. Changes in the walls are also evaluated in terms of their significance for dispersal of the sperms at maturity. The sequence of protoplasmic events leading to maturation of sperms was described elsewhere (Paolillo et al., 1968a,b). MATERIALS AND METHODS Polytrichum juniperinum Hedw., collected at Portland Arch, Indiana, was used for this study. Methods used include conventional gluteraldehyde fixation, Epon embedding and thin 1 Supported in part by National Science Foundation Grant GB-25097. 2 Section of Genetics, Development and Physiology, Cornell University, Ithaca, New York 14853. SPresent address: College of Veterinary Medicine, Cornell University, Ithaca, New York 14853. This content downloaded from 157.55.39.96 on Mon, 18 Apr 2016 08:29:18 UTC All use subject to http://about.jstor.org/terms 1976] PAOLILLO & CUKIERSKI: SPERMATOGENESIS IN POLYTRICHUM 467 sectioning (Paolillo et al., 1968a,b). Additional observations were made with a Phillips 300 microscope and an improved staining technique, in which 5% methanolic uranyl acetate was applied for 30-40 min. in a covered dish in a cool room (160C) to minimize evaporation. This was followed by lead citrate. Using this procedure, greater contrast and fewer precipitates were obtained than with shorter applications of 25% methanolic uranyl acetate (Stempak & Ward, 1964) at room temperature, followed by lead citrate. Terminology applied to stages of development is according to Allen (1912).

Areas of soil surface covered by mosses in hardwood and northern coniferous forest ecosystems of Camels Hump Mountain, Vermont, decreased between 1965 and 1979. To evaluate the possibility that this decline might be due to a combination of acidic deposition and metal accumulations in the acidic soil solution, one of the dominant moss species, Polytrichum ohioensis Ren. et Card., was grown in vitro at different pH values in the presence of aluminum, copper, lead and zinc ions. Suppression of the growth of gametophyte tissues was a function of metal ion concentration and the pH of the nutrient medium. The simulation experiments indicated that depauperization of mosses in these mountainous ecosystems could be due to metal ions in acidic soil solutions.

Strong segregation of sexes in populations of Atrichum angustatum (Brid.) B.S.G. is attributed to vegetative proliferation of unisexual clones. The distribution of gamete dispersal distances in this moss is highly leptokurtic, with a mean of 2.11 cm and an observed maximum of 11.0 cm. Overall shoot density is 4.6 per cm2, giving neighborhood size of about 225 individuals and neighborhood area of about .005 m2. When leafy vegetative gametophores are dissected and classified as to sex, the overall sex ratio approaches unity. These observations are compared to previous studies of sporophyte production in relation to population sex ratio and relative spatial distribution of males and females. It is concluded that sex ratio and spatial pattern to a large degree determine levels of sporophyte production in dioicous moss populations. The few data currently available for dioicous mosses regarding spatial pattern of male and female plants and gamete dispersal distances are intriguing, but much less than definitive. Quantitative field studies of the ratio and distribution of male and female gametophores are lacking. Gamete dispersal distances are likewise known only from reports of absolute maximum and minimum distances. Such information is important in any discussion of the population biology of mosses. The present study was undertaken to cast some light on these basic questions. Newton (1971) has recently reviewed the bryological literature with reference to sex ratios in moss populations. In studies of Mnium undulatum Hedw. an approximate 4:1 bias in favor of females was discovered (Lacey, 1950; DeSloover, 1966; Newton, 1971). Similar results were obtained for Climacium dendroides Web. & Mohr (Bedford, 1938b) and Breutelia arcuata Schimp. (Bedford, 1940). Tallis (1957), however, found an excess of male gametophores in his analysis of Rhacomitrium lanuginosum (Hedw.) Brid. The study of sex ratios in bryophytes is complicated by the presence of nonreproductive shoots. Riemann (1972) scored 10,000 herbarium specimens of Rhytidiadelphus triquetrus (Hedw.) Warnst., of which 49% were female, 33% were male and 18% were apparently sterile. Using cytological markers to distinguish sexes, Newton (1971) found that the frequency of production of antheridia underestimates the actual number of male gametophytes. Both large-scale and small-scale distribution patterns and ratios of male and female 1 I thank Lewis E. Anderson and Ann H. Stoneburner for encouragement, advice and criticism. They, with Janis Antonovics, Norton G. Miller and Maxine A. Watson, commented on an earlier draft of the manuscript. 2 Department of Botany, Duke University, Durham, North Carolina 27706. Present address: Department of Biology, Texas AM 1938b), Breutelia arcuata (Bedford, 1940), Aulacomnium androgynum (Hedw.) Schwaegr. (Persson, 1940), Leucobryum glaucum (Hedw.) Schimp. (Persson, 1943), Mnium undulatum (Lacey, 1950), Bryoxiphium norvegicum (Brid.) Mitt. (Hagne & Welch, 1951), Pleurozium schreberi (Brid.) Mitt. (Longton & Greene, 1969), Rhytidiadelphus triquetrus (Riemann, 1972) and several island species of eastern Asia (Iwatsuki, 1972). Quantitative tests of the assumption that gene flow in terms of gamete dispersal is over very short distances in moss populations have been few. More typical are qualitative observations like those of Harvey-Gibson and Miller-Brown (1927) that mites, springtails and other arthropods that feed on the paraphyses of Polytrichum commune Hedw. frequently transport sperms "a considerable distance." Goebel (1930; p. 968) and Bower (1935; pp. 82-83) concluded that aquatic mosses produce sporophytes only rarely due to dilution of sperms. Bedford (1938b) never found female plants bearing sporophytes more than three inches from a male in Climacium dendroides. In Breutelia arcuata, which has a "splash cup" mechanism for dispersal of sperms, the distance between sporophyte-bearing plants and male gametophores never exceeds one inch (Bedford, 1940). Brodie (1951) was able to experimentally disperse sperms up to two feet from the splash cups of Polytrichum ohioense Ren. & Card. Longton and Greene (1969) estimated the fertilization range of Pleurozium schreberi to be 7 to 10 cm, and for Mnium undulatum distances range from 2.5 to 12 cm with a maximum of 20 cm (Newton, 1971). Riemann's (1972) populations of Rhytidiadelphus triquetrus showed high sporophyte production when the mean distance between sexes was less than 3 cm and no sporophyte production at distances greater than 6 cm. In all of these studies minimum estimates of gene flow distances were obtained, since the distance from a sporophyte to the nearest male gametophyte obviously tends to underestimate the actual distances traveled by sperms. The only data regarding gamete dispersal in monoicous mosses is the study of Weissia controversa Hedw. by Anderson and Lemmon (1974) in which the average gene flow distance was measured to be 12.3 mm and the median, slightly less than 5 mm. The maximum distance observed was 40 mm. Atrichum angustatum (Brid.) B.S.G. is a common dioicous moss of disturbed sites in oak-hickory forests of the eastern United States (Nyholm, 1971; Crum, 1973). In the spring and early summer leafy male gametophytes produce antheridia within perigonial inflorescences that are quite distinct from the inflorescences of females. The growth habit of A. angustatum is similar to other dioicous acrocarpous mosses, and dense, pure stands are often developed. These characteristics facilitate mapping and measurement of distances between plants. The plants are perennial and may produce additional antheridia on leafy shoots extending from the previous year's perigonium. Atrichum therefore, like Polytrichum, is one of the few moss genera in which production of antheridia does not use up the apical cell (Watson, 1971; p. 112). These observations are currently under further investigation by monitoring marked individual leafy gametophytes. This content downloaded from 157.55.39.104 on Sun, 19 Jun 2016 06:08:01 UTC All use subject to http://about.jstor.org/terms I I I I I I I I I I I I I I 0-0000000000-00 000000 0 000000000000 0000 00 0 000-0000000000 0000 00000000-0o----000-000000000-0000-o000000000000000000000000000000000000000000000000000000000000000-00--000o00 -*-oo0 o o o oo---000000000 00000000000000000000000000000 -00000000000000000000000000000-0000000 0 *000000000000000000-0-o000000-0000-0-000--0000000o-0 ---om0000-0000 000-00o-o--mo-@ @ @ * 0000-00 00-0--0 00000000000000000000000000000000000000 000 00--00000000-00--000-0-0-0 0 0000-o0000000000o -0-o--00 e000000--0 00000000000--00-0000-00000*0000000000000000000000000000000o0000-000o0-000-0-00000-00oo----o000 0000 -00 00 -0--00000-00000 00ooooooooooo'ooo -oo00 o--oooooooooooooo ---00-0-00-0000---0-----0-0000 --000000000 000 00000000 --00000--00-00000000000 000 000 FIGURE 1. Line transects in the Atrichum angustatum study population in the Duke Forest, Orange County, North Carolina. Each division marks 10 cm. Dashes represent male gametophores with perigonia; open circles, gametophores of undetermined sex; and solid circles, female gametophores with sporophytes. The longer axis from left to right is oriented north-northeast. L,-I 00

After exposure to 1000, 1600, 2200 and 2800 roentgens of gamma radiation, some of the irradiated and control gametophores of Polytrichum commune Hedw. were dried in a desiccator, then sealed in moisture free jars for four months. Regeneration of desiccated material occurred in Knops' solution but not on Knops' agar. In many of the plants that received the three highest doses of radiation, regeneration and growth in height appeared to be rapid at first, then comparatively slow after several weeks. In the plants that received 1000 roentgens the amount of regeneration and growth in height was more constant throughout the period of observation. Little is known about regeneration in mosses exposed to ionizing radiations above the normal background levels. The purpose of this study was to determine if and to what extent regeneration in Polytrichum commune Hedw. would be effected by various doses of gamma radiation and drying. Growth and development of gametophores from irradiated sporocytes and spores was reported by the authors previously (1974). MATERIALS AND METHODS Details on the collection and handling of plant material, observations made, nutrient media used, conditions in growth chamber, etc., were described by Grossman and Hillson (1974) for that part of the investigation dealing with irradiation of spores and sporocytes. The same methods and materials were used in the treatment of gametophores. Plants were separated into five groups of which four were irradiated and one served as control. In the irradiation of mature gametophores, Groups I and II received 9.60 r of gamma radiation per hour each, for a total of 1600 r and 2800 r, respectively. Groups III and IV received 7.81 r per hour each, for a total of 1000 r and 2200 r, respectively. After being irradiated, the plants were soaked and agitated in distilled water to remove contaminants. Cuttings of leaves and leaf-bearing stem segments (herein referred to as stem/leaf cuttings) were made and placed on Knops' agar plates which in turn were placed into a growth chamber. Seventy-five leaf and twenty-five stem/leaf cuttings were made for each group. Some of the irradiated and control gametophores were placed in desiccators for two days. The dried plants were sealed to eliminate any outside source of moisture. At the end of four 1This paper is based on a portion of a thesis submitted by the first author in partial fulfillment of the requirements for the degree of Doctor of Philosophy, The Pennsylvania State University. 2Biology Department, The Pennsylvania State University, Fayette Campus, Uniontown, Pennsylvania 15401. SBiology Department, The Pennsylvania State University, University Park, Pennsylvania 16802. This content downloaded from 40.77.167.129 on Wed, 24 May 2017 20:44:02 UTC All use subject to http://about.jstor.org/terms 1976] GROSSMAN & HILLSON: GAMMA RADIATION OF POLYTRICHUM 489 TABLE 1. Number and size of proliferations from leaf and stem/leaf cuttings of nondesiccated gametophores after five weeks and fifteen weeks. Week Five Week Fifteen Group and Number of Size Number of Size Treatment Proliferations Range (mm) Proliferations Range (mm) I (1600 r) 168 .5-5 147 1-6 II (2800 r) 111 .5-2 78 .5-3.5 III (1000 r) 103 .5-3 150 1-7.5 IV (2200 r) 71 .5-3 85 .5-4 Control 60 .5-5.5 75 1-10.5 months the jars were opened and leaf and stem/leaf cuttings were made from the dried plants. Some of the cuttings were placed on Knops' agar plates and the re aining cuttings were placed in vials of Knops' solution. The agar and solution were identical in nutrient content. These plates and vials were placed in a growth chamber. Observations were made at five, ten and fifteen weeks after the material was placed in the growth chamber. At week 15 all plants were transferred to soil and final observations were made six months after the transfer. Anatomical studies made of leaf and stem from irradiated and control material were compared with those from specimens collected in the field.

Polytrichum appalachianum Anderson, sp. nov., is described as a new species. Limited to the southern Blue Ridge Province of the Appalachian Mountains, it has previously been known as P. xanthopilum Wils. [Polytrichastrum xanthopilum (Wils.) G. L. Sm.]. Recently discovered sporophytes from North Carolina, however, show clearly that American plants do not belong to this species, necessitating the description of a new taxon. The new species differs from P. xanthopilum principally in its lack ofa bulbous hypophysis at the base of the capsule, the absence ofa constriction between the urn and hypophysis, and a less pyriform terminal cell of the leaf lamellae. The new species resembles most closely P. formosum Hedw. and P. longisetum Brid. Its distribution, ecology, and cytology are discussed. In connection with his generic studies of the Polytrichaceae, G. L. Smith (1971) discovered a previously unrecognized species ofPolytrichum in North America that was narrowly restricted to the higher elevations of the southern Blue Ridge Province of the Southern Appalachian Mountains, specifically in North Carolina and Tennessee. All the specimens that Smith examined are sterile and originally had been identified as P. longisetum Brid. (P. gracile Turn.), P. pallidisetum Funck, or P. commune Hedw. Based on similarities in the structure of the terminal cells of the leaf lamellae, Smith identified this sterile material as P. xanthopilum Wils. ex Mitt. [as Polytrichastrum xanthopilum (Wils. ex Mitt.) G. L. Sm.], a Himalayan species. Crum and Anderson (198 1) included the species in their flora of eastern North America (as Polytrichum), but with some reservations: "We have no reason to disagree with his [Smith's] opinion, although the Appalachian plants are not a perfect match for plants we have seen from Nepal (collected by Z. Iwatsuki) .... In American plants the lamellae are somewhat shorter, and the terminal cells are not particularly bottle-shaped." Recently, I discovered fruiting plants of this taxon in North Carolina and the capsules differ significantly from plants of P. xanthopilum from Nepal. The American plants clearly do not belong to this species and I have been unable to locate any other species with which the Appalachian material can be associated. It is necessary, therefore, to describe a new species. Polytrichum appalachianum, sp. nov. (Fig. 1-7) P. xanthopilum auct. amer., non Wils. ex Mitt. Polytrichastrum xanthopilum auct. amer. Cellulae terminales lamellarum in sectione transversali oliquanto pyriformes, parietibus apice incrassatis, e latere irregulariter et obtuse serrulatis. Capsula quadrangularis, operculo rostrato, apophyse inferne evoluta. Plant 2-10 cm high, dark green to blackish, in loose, often semi-erect tufts, shorter plants more densely aggregated and erect. Stems simple, rarely forked, sparsely to densely radiculose, often with whitish tomentum extending well up the stem. Leaves erect-spreading when dry, often recurved at the tips, more crowded in short, erect plants, when wet widely spreading and generally somewhat recurved, 5-10 mm long, lanceolate-acuminate from a sheathing base about 2 mm long, ending in a short to moderately long, dark to red-brown toothed point; margins sharply serrate nearly to the base of the 0007-2745/87/1-5$0.65/0 This content downloaded from 157.55.39.58 on Sun, 31 Jul 2016 05:27:34 UTC All use subject to http://about.jstor.org/terms 2 THE BRYOLOGIST [Volume 90

Antheridia of Funaria empty their contents differently from an- theridia of Polytrichum, Atrichum and Mnium. In all these genera the rapid phase of sperm release is powered by a contraction of the jacket upon opening. But the slow phase of release in Funaria is powered by the swelling of the sperm mass, whereas in the other genera the slow phase is powered by swelling of a fluid in the antheridial chamber, by osmosis. The last of the sperms is pulled from the chamber by the cohesiveness of the sperm mass in Funaria, whereas the last of the sperms are pushed from the chamber by the swelling fluid in the other genera. Antheridia of Funaria can empty their contents into M sucrose solutions, whereas antheridia of the other genera can not. From the reports of either Goebel (1898, 1930) or Muggoch and Walton (1942) one could draw the conclusion that antheridia of diverse mosses open and empty their contents in a uniform fashion. However, these accounts of the operation of antheridia are not in agreement on how antheridia empty, and both lack experimental observa- tions to elucidate the supposed physiological bases for operation of the antheridia. Studies on Polytrichum (Paolillo, 1975), Atrichum and Mnium (Paolillo, 1977) have shown that emptying of antheridia occurs in two phases. The first phase is rapid and is powered by a contraction of the jacket, of the kind noted by Lorch (1931). The second phase is slow, and depends on uptake of water by osmosis into a fluid that is present in the base of the chamber before an antheridium opens. The presence of this fluid as a normal feature of maturation was not taken into account by Goebel (1898, 1930), and it is quite at odds with the account of Muggoch and Walton (1942). Similarities among the three genera that have been investigated experimentally are striking, but this is not sufficient cause for concluding that all moss antheridia empty their contents in the same way. This report deals with the discovery that emptying of antheridia in Funaria differs from that of Polytrichum, Atrichum and Mnium. The process in Funaria seems to depend on the principles outlined by Goebel (1898, 1930) in the description that he believed to apply to all the genera he studied, viz., a swelling of the sperm mass itself. It is also shown here that the criteria I have applied in determining when antheridia operate in the same way are suitable for a systematic survey of the operation of antheridia in the mosses.

In the temperate moss species Polytrichum commune Hedw. field studies demonstrated that growth segments which are formed by changing patterns of leaf morphology are repeated annually. Evidence for exceedingly smallscale microhabitat variability in available water was found in the scattered distribution of desiccated stems in space and time, throughout the population under study. Moss turfs were extremely sensitive to disturbance which apparently altered the water-regulating capacity of the normally unbroken moss canopy. Mortality rates reported were undoubtedly elevated due to disturbance of the moss canopy during the course of this investigation. The last few years have witnessed a growing interest in the study of demography of plant populations (cf. Harper & White, 1974 for review). Allied to this interest has been a need to identify plant species in which ages of individual plants may be easily determined on the basis of direct morphological assessment. Formation of annual growth rings in woody perennials is the best known example of this type of interpretable morphological periodicity. Tree ring analysis has frequently been used in the study of historical events within a region or as an aid in the construction of management schedules for commercially harvested stands. Only recently, however, has this type of information been used in the construction of life tables for the study of the dynamics of natural forest stands (Hett & Loucks, 1971, 1968; Hett, 1971). Even less information is available for perennial herbs, which in general lack reliable morphological criteria for assigning age. Work by Tamm (1948, 1956, 1972a, 1972b) on life histories of woodland herbs relied exclusively upon mapping of individuals over years of observation in permanent plots. Similar methodology was employed in the recent work of Sarukhain and Harper (1973), in which successive cohorts of three Ranunculus spp. were mapped and observed over a three year period in order to elucidate the differences among the three species in life history patterns. Several herbaceous plant species do, however, possess sound morphological cues upon which a life history analysis may be structured. For example Kerster (1968), 1This work was done in partial fulfillment of requirements for the degree of Doctor of Philosophy, Yale University, 1974. It was supported in part by USPHS Predoctoral Training Grant in Developmental Biology and a Sigma Xi Grant-in-Aide of Research. I would like to thank the New Haven Water Company for access to their land. 2 Department of Biology, University of Utah, Salt Lake City, Utah 84112. This content downloaded from 207.46.13.115 on Sat, 08 Oct 2016 05:20:07 UTC All use subject to http://about.jstor.org/terms 1975] WATSON: GROWTH PERIODICITY IN POLYTRICHUM 415

Mosses of the coastal dune ecosystem were studied to determine whether a tolerance to chronic salt spray had evolved, if so, whether it was a species or population level trait, and whether it is important in the dune moss community. Ceratodon purpureus (Hedw.) Brid., Aulacomnium palustre (Hedw.) Schwaegr., and Polytrichum commune Hedw. from three different New Jersey habitats were misted with salt spray to simulate the secondary dune environment. No species survived salt spray alone. When rain was added however, Ceratodon did exhibit some salt tolerance. The results suggest that salt spray is sufficient to severely restrict the dune moss community, and that of the possible strategies, Ceratodon has evolved a salt tolerance, Aulacomnium and Polytrichum depend on salt dilution, and that recovery following salt stress is of secondary importance. There were no significant differences noted in response to salt spray among populations within a species, and this result was not affected by varying the substrate. Therefore salt tolerance is a species level trait, not a population level trait, suggesting that ecotypic differentiation has not taken place in response to salt spray. Since the description of the salt-spray coastal dune community as a climax (Wells & Shunk, 1938), much attention has been focused on salt spray as an ecological factor. Aerial salt suspension, a result of wind and wave action, has been shown to be both a source of necessary nutrients (Art et al., 1974) and a controlling factor in plant distribution and growth through salt damage (Oosting & Billings, 1942; Martin, 1959). Little attention, however, has been paid to the bryophyte segment of this community. Moul (1969) described only Dicranum scoparium Hedw. and Polytrichum commune Hedw. from Monomoy Island, Mass. In a later study of the marine fringe of the northeastern United States Moul (1973) listed Polytrichum piliferum Schreb. and Ceratodon purpureus (Hedw.) Brid. as occurring on the dunes, with Sphagnum spp. and Aulacomnium palustre (Hedw.) Schwaegr. growing in wet hollows. Neither Petry and Norman (1968) nor O'Connor and Terry (1972) mention any mosses, although both, as did Moul (1969, 1973), mention several lichens. Martin (1959) studied the flora and ecology of Island Beach State Park, N. J., extensively but did not include bryophytes. Only British workers (e.g. Gimingham, 1948; Birse et al., 1957) have appreciated the potential role of bryophytes in this ecosystem. Several workers (Oosting & Billings, 1942; Martin, 1959) assessed the effects of salt spray on vascular plants. Their results indicated that salt spray may limit the distribution of these forms within the dune ecosystem by killing apical buds of plants directly exposed to impaction. These plants, by their very presence in this system, must, however, be somewhat tolerant to salt spray or have means to avoid it. This study was designed to 1 Department of Botany, Rutgers University, New Brunswick, New Jersey 08903, U.S.A. This content downloaded from 157.55.39.179 on Mon, 11 Apr 2016 12:33:03 UTC All use subject to http://about.jstor.org/terms 58 THE BRYOLOGIST [Volume 78 determine whether those mosses inhabiting this area of chronic salt stress have evolved, either at the species or population level, a mechanism of salt tolerance. It is hoped that this will help determine what factors are important in coastal moss distribution. MATERIALS AND METHODS Three species growing in both coastal and non-coastal habitats were used in the experiments: Aulacomnium palustre, Polytrichum commune, and Ceratodon purpureus. Samples of populations of the species were collected in March 1974 from beach, pine barrens and upland sites in central New Jersey. Beach populations grew at Island Beach State Park south of Seaside Park, where Ceratodon was on the secondary dune and Aulacomnium and Polytrichum were in the swale behind the secondary dune. A pine barrens population of Ceratodon grew at Lebanon State Forest near Chatsworth, about 38 km from the coast on the sandy coastal plain dominated by Pinus rigida. Upland populations of all 3 species grew at the Rutgers University Kilmer Woods in Piscataway, about 40 km from the coast in an old field on red shale Piedmont. Soil was obtained at each site at the time of harvest. Voucher specimens are in the Chrysler Herbarium of Rutgers University. Clumps of 100 shoots of Aulacomnium and Polytrichum and 300 shoots of Ceratodon were placed on soil in 30 x 45 x 7.5 cm wooden flats and maintained in a coldframe. The coldframe permitted tight control of precipitation, but otherwise permitted ambient light and a near-normal temperature regime, with the exception of no temperatures below 100C. All populations were represented in every flat, and 30 cm high clear polyethylene barriers separated various treatments. To simulate the natural level of aerial salt impaction on the back of the secondary dune ( Oosting & Billings, 1942; Martin, 1959), natural sea water (salinity = 27.9 parts per thousand) was applied with a garden sprayer, in a fine mist at about 10? 2 ml/treatment. This provided approximately 20 mg of salt per dmi of flat per day. Since the wind does not always blow at the beach, spray would not always hit the dunes. Therefore treatments were given on 33 of 44 days during the experimental period. Control plants were treated similarly with fresh water. Periodic rain storms are not uncommon in coastal dune areas and may serve to wash or dilute some of the impacted salt. Rain, relative to salt spray, is characterized by larger drop size and less frequent occurrence. To take this factor into account, certain of the flats which received salt spray also received 5 simulated rains during the 44 day treatment period. Approximately 1 cm of water from a sprinkling can was applied over the entire surface of the flats. All plants were well soaked by this treatment. To determine if substrate affected tolerance of these populations to salt spray, three flats of mosses, one with each soil type, were used in the salt and rain treatment. Again each species from each habitat was represented in every flat. Control and salt spray treatments were done on beach soil; however results in the graphs for the salt and rain treatment are presented as an average of the three soil types. After the 44-day salt treatment, the clumps of moss were removed from the coldframe and selected shoots examined to determine if the tips were either green, and hence alive, or brown and necrotic. Mature leaves along the stem were separately examined on the same shoots. Edge plants were not counted. One hundred random shoots of Ceratodon, 40 of Polytrichum and 50 of Aulacomnium were examined under a dissecting microscope. An analysis of variance was utilized to determine statistical significance. Since many mosses are adapted to spend long dormant periods under desiccation stress, and then resume activity upon wetting, a 14-day post-treatment recovery period was added to assess percent recovery from salt stress. After salt treatment examination the plants and flats were flushed clean of salt with a garden sprinkler and returned to the coldframe. The flats were misted daily with fresh water for the next 14 days. The plants were then reexamined using the same methods of assay. Results for stem, leaves and shoot tips are nearly identical, and hence the shoot tip data presented may be considered representative.

The previous catalog of mosses known from Alaska was published in 1902 and included 280 species and varieties. The present enumeration, compiled from published records, lists 601 taxa in 150 genera and 43 families. Bryological research in Alaska has had two periods of development. The first began with small collections made in the mid-nineteenth century, often by members of a general scientific expedition. By 1902 Cardot and Th~riot (1902) were able to list, in their enumeration of the mosses collected by the Harriman Expedition to coastal regions of Alaska, 280 species of mosses based upon their own collections and those of some ten previous reports. The 1913 Kelp Expedition, also primarily a coastal study, added an additional 55 taxa (Holzinger & Frye, 1921). R. S. Williams (1901, 1903, 1912, 1919), in studies primarily centered in the Yukon Territory, added several species. In 1914 Evans was able to report 105 hepatics from Alaska. (Worley (1970) gives a list of liverworts now known from Alaska.) During these early years many collections were made by nonbryologists and were usually from sites seldom far from the coast. A few, such as those by Hazen and Turner (1886) were made in the interior, but mountains and the Arctic were rarely investigated bryologically. From 1921 until the early 1940's there were few publications on Alaskan mosses. The field work of E. Hult~n in 1932 begins the second era of Alaskan bryology. Bartram (1938) reported the mosses collected from the south coastal regions by Hult6n and by W. J. Eyerdam, a long-time amateur collector of plants. It was, however, in the continuing accumulation of vascular-plant specimens from throughout Alaska by Hult~n that Herman Persson found the material for many years of bryophyte investigations. From herbarium sheets Persson located, separated, determined, and reported in a series of papers (many in THE BRYOLOGIST) the bryophytes that had accidentally been pressed along with the intended plants. From the 1940's to the present he also reported (often in joint authorship) the collections of a number of nonbryologists and bryologists from numerous, widespread Alaskan localities. Notable contributors have been E. Hult~n and Frbre E. Lepage who collected the first substantial arctic material, L. D. Stair and his daughter who collected in Yakutat Bay, and several important collections from the interior, especially the mountain ranges, by W. Weber, L. A. Viereck, H. T. Shacklette, E. M. Sherrard, O. Gjaerevoll, and others. Many of these workers have also published their findings separately. Persson also re-examined 1 We thank Dr. W. B. Schofield for advice throughout the preparation of this list and for financial assistance through the National Research Council of Canada. 2 Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada. * Hattori Botanical Laboratory, Obi, Nichinan, Miyazaki Prefecture, Japan. This content downloaded from 207.46.13.111 on Tue, 09 Aug 2016 05:19:39 UTC All use subject to http://about.jstor.org/terms 60 THE BRYOLOGIST [Volume 73 the Alaskan material in the Kindberg herbarium collected by J. Macoun. Other bryological investigations were made by R. Thomas at Iliamna Lake (1952), by A. M. Harvill from various Alaskan sites (1947a, 1947b, 1948, 1950), by Frye and Clark (1946) reporting on material from Attu Island, and by several other workers reporting in a variety of papers, notes, and monographs. During this period the gap in arctic studies was being filled by the research of W. C. Steere. His many trips to the Arctic brought the knowledge of Alaskan arctic bryophytes up to the level of most of the other regions in the state. Although never presenting a complete list of arctic Alaska mosses, Steere reported many new records in his numerous articles on the North American Arctic. Bryological studies in Alaska have now established the major floristic components, but many distributions are incomplete and a number of critical areas, especially certain mountain ranges and some coastal regions, need intensive study. Many species new to the state, and perhaps even to science, are certainly yet to be discovered (for example, the recent discoveries of Crumia deciduidentata (Sharp & Iwatsuki, 1969) and Pterigoneurum arcticum (Steere, 1959). Major collections in the last five years have been made by A. J. Sharp and Z. Iwatsuki in the Aleutian Islands and the Alexander Archipelago and by I. A. Worley in southeastern Alaska. There are also unpublished collections by F. J. Hermann and B. Neiland. Duplicates of some of the Hermann specimens have been distributed. The last published report attempting to list all known Alaskan mosses was made in 1902 (Cardot & Th6riot, 1902). Persson (1949) totaled, but did not list, the species of mosses from Alaska and the Yukon. His count of published and unpublished records of mosses was 27 Sphagna, 265 acrocarpous mosses, and 140 pleurocarpous mosses, making a total of 432 taxa. Since that time there have been numerous additions to the Alaskan flora. With the completion of E. Hult6n's Flora of Alaska and Neighboring Territories (1968), it was felt that an enumeration of the mosses now reported was due. The present list was compiled from the literature and includes 33 Sphagna, 354 acrocarpous mosses, and 214 pleurocarpous mosses-a total of 601 taxa. With few exceptions the synonymy of Crum, Steere and Anderson (1965) has been followed. For the treatment of the Mniaceae the revisions of Koponen (1968) have been utilized. No attempt has been made to verify determinations or species reports. Occasional entries are almost certainly misdeterminations; they are single reports of common species otherwise not known from the northwest Pacific region and have not been recollected in recent times. Examples of these include Polytrichum ohioensis, Ulota hutchinsiae and var. rufescens, and Cirrophyllum illecebrum. However, until the material is examined they have been retained in the list. When a taxon is known from Alaska from only one or two reports a reference is cited following the name of the taxon in the list. Subspecific taxa are a problem because many of the older ones, which have not been reported since the original typification, have never been reduced to synonymy, although it is clear that they should be. In general, we have omitted those which are excluded by Grout (1928--40) and by Crum, Steere, and Anderson (1965). Some names included are dubious as good taxa but they are retained pending further study. In the genus Sphagnum, with one exception, the list does not include varieties or subspecies. Grout, in the Moss Flora of North America (1928-40), gives without specimen citation the only Alaskan report for the following taxa: Polytrichum commune var. perigoniale, P. ohioense, Ditrichum pusillum, Ceratodon purpureus var. conicus, This content downloaded from 207.46.13.111 on Tue, 09 Aug 2016 05:19:39 UTC All use subject to http://about.jstor.org/terms 1970] WORLEY & IWATSUKI: MOSSES OF ALASKA 61 Trematodon ambiguus, Oncophorus wahlenbergii var. compactus, Dicranum muhlenbeckii var. cirratum, Plagiobryum zierii, Amblyodon dealbatus, Anacolia menziesii, Philonotis fontana var. borealis, Zygodon rupestris, Hygrohypnum bestii, and H. luridum var. julaceum. Both Funaria hygrometrica var. arctica and F. microstoma var. obtusifolia appear in the list although Persson (1962a) considers that perhaps these records represent but one arctic taxon. Brotherella roellii has been reported from Kuiu Island by Harvill (1950). It is possible that this is actually an undescribed species of Brotherella known from British Columbia (Schofield, 1968). The Rhacomitrium heterostichum complex in western North America is currently under study by K. Banu of the University of British Columbia; her findings, soon to be reported, have not been incorporated in this paper. The list is presented by families in the order used by Crum, Steere, and Anderson (1965). THE LIST OF SPECIES

Fresh spores of Polytrichum juniperinum germinate rapidly under laboratory conditions. The pattern of CO, exchange during germination indicates that respiration is maximized as soon as hydration is complete (10 minutes) and that photosynthesis is maximized more slowly (80 minutes). Net photosynthesis is attained after 25 minutes. Aging the spores for one year did not alter the rapidity with which respiration begins, but the rate of respiration was lowered and the attainment of the compensation point and maximum photosynthetic rate were markedly delayed. The spores of a slower-germinating species, P. ohioense, appear to hydrate as quickly as those of P. juniperinum. But in contrast, for the first 48 hours respiration and photosynthesis increase in parallel. Net photosynthesis is not attained until 48 hours after the beginning of germination. The cumulative evidence suggests a plastid-localized synthesis that limits the rate of photosynthesis. Reighard (1967) reported that mature spores of Polytrichum juniperinum and P. ohioense contain typical chloroplasts. She also noted that ultrastructural changes leading to germ tube emergence proceed more rapidly in P. juniperinum than in P. ohioense. Paolillo and Jagels (1969) reported that spores of P. iuniperinum attained a high, steady rate of respiration ca. 10 minutes after coming into contact with water and a maximum photosynthetic rate ca. 80 minutes after wetting, at 250C. The investigations described in the present report were designed to determine if the patterns of CO2 exchange are different in fastand slow-germinating spores, and to compare species differences with any effect of aging in the fast-germinating species. An understanding of these matters is crucial to further experimental work on spore germination in Polytrichum and to elucidating the differences between sporophytic and gametophytic patterns of CO2 exchange. The sporophyte of Polytrichum is incapable of net photosynthesis, whereas there is no such limitation on the gametophyte (Paolillo & Bazzaz, 1968). MATERIALS AND MmiETHODS Spores were obtained from the 1968 and 1969 crops of P. juniperinum Hedw. and from the 1969 crop of P. ohioense Ren. & Card. Spores were harvested either 1) directly after the capsules were collected or 2) after capsules had been stored until within one week of the 1 This study was accomplished with the aid of National Science Foundation grant GB-6520, at the University of Illinois, Urbana. 2 Department of Botany, University of Illinois, Urbana, Illinois 61801. SPresent address: Section of Genetics, Development, and Physiology, Cornell University, Ithaca, New York 14850. This content downloaded from 157.55.39.70 on Tue, 06 Sep 2016 05:47:17 UTC All use subject to http://about.jstor.org/terms 1970] PAOLILLO & PAYNE: CO2 EXCHANGE IN POLYTRICHUM SPORES 655 time the spores were to be used. In the text, the spores in 1) are said to be "stored in the vial," and those in 2) are referred to as "stored in the capsule." Capsules and vials were stored at 22-24?C in the dark in an air-conditioned laboratory. Methods for harvesting spores and the location for field collections were the same as those given in Paolillo and Jagels (19q9). It is more difficult to collect large quantities of P. ohioense spores than P. Juniperinum spork~s. Our experience is that the mature capsules of P. juniperinum are slow to lose their lids and numerous full capsules can be collected after shedding begins. Although we followed the maturation of P. ohioense closely, the sporophytes throughout our collecting site were quick to lose their lids and the collections were thereby rendered less efficient. The problem was partly alleviated by the relatively larger size of the P. ohioense capsules and the proportionately higher spore content per capsule in this species. We were reluctant to take capsules of either species from the field before shedding started because of the unknown effect this might have on the results of the experiments. The CO2-exchange patterns of 50-mg batches of spores were measured at 25?C in an infrared gas analyzer (IRGA) as in the earlier work (Paolillo & Jagels, 1969), with slight modifications of techniques where mentioned in the text. The modifications included substituting Voth's (1943) solution 5 (M5) for deionized water in the later experiments, and the incubation of spores on filter paper placed on M5 agar (M5 solidified with 1% Difco Bacto Agar) for long-term incubations prior to gas analysis. Incubations were at 250C under continuous illumination (1200 f-c, incandescent lamps, as used in the gas analysis).

POLYTRICIUM STRICTUM IN PENNSYLVANIA. OTTO E. JENNINGS. In the northwestern corner of Pennsylvania, near Linesville, in Crawford County, there is a great area of swampy or boggy land lying to the south of a row of morainal hills. This area collectively is known as the Pymatuning Swamp and extends with one interruption for a distance of about seventeen miles and in one place is about one mile wide. During the last six years the writer has made repeated excursions to this swamp, studing the flora both ecologically and systematically, and a number of very interesting things, botanically speaking, are to be found there. The bog is in places a very characteristic Canadian TamarackSphagnum bog (Larix-Sfkagnum association) and in places has become southern in its relationship, with a Black Ash-Lizard Tail swamp (Fraxinus nigra-Saururus association). In one place near Linesville there is a small area, not over half-an-acre in extent, where the vegetation is made up exclusively of a Cassahdra-Polytrichum heath,and it was with considerable surprise and interest that the moss was found to be typical Polytrichum stricturn Banks. (Collected May 28, 19o8, O. E. Jennings.) The occurrence here of this species of Polytrichum is noteworthy in that the species is so distinctly northern in its distribution and as far south as the northern states it is mainly restricted to rather elevated boggy alpine regions. So far as the writer is aware this species has never before been reported from either Pennsylvania or from Ohio, whose boundry line is but a few miles distant, and, furthermore, the moss occurs here at a comparatively low elevation, about 980 feet above the sea. Carnegie Museum, August 22, 1910.

In Funaria hygromrnetrica, low temperature (100 C) is the critical factor in the induction of sex organs while day length seems to have no effect as long as a certain minimum period of illumination is provided. The purpose of this study was to investigate some of the factors which effect the initiation of sexuality in Funaria hygrometrica Hedw. as evidenced by the formation and functioning of antherida and archegonia. Although the stimuli which trigger the onset of the reproductive phase have been investigated in algae, fungi, and flowering plants, the Bryophyta have been relatively neglected in this respect. Photoperiod has been implicated in gametangiophore production in the liverwort Marchantia (Voth & Hamner 1949) and has been shown to affect development, although not to cause initiation, of the sporophyte of Polytrichum aloides (Hughes 1962). Morris (1958) stated that in five species of leafy liverworts, the onset of sexual reproduction is primarily a photoperiodic response. Benson-Evans (1964) reported that sexuality in Sphagnum plumulosum is initiated by short days but that Polytrichum aloides appears to be day length neutral and, in fact, initiation of sexuality is temperature-dependent. Von Wettstein (1924) was able to bring about sexual reproduction in Funaria hygrometrica by 'culturing it in pots on the north side of his "Moosgewichshaus" where, he stated, the plants would remain especially cool in

Of Pleuridium there are 28 species described, and all but 10 from original specimens, but of these P. Bolanderi is from Chicago, and P. Ravenelii from Louisiana. Astomum is not completed in this fascicle, 18 species are described but none are figured. Thus far it does not look as if much new light were thrown on North American species, as a work of this magnitude and celerity cannot be very critical. New York Botanical Garden.

The gametophore of Dendroligotrichum dendroides (Hedw.) Broth. is differentiated into a multiseriate cortical region in which is embedded a central cylinder of tissues. The central cylinder consists of a core of cells, the hydroids, surrounded by a leptome sheath of parenchyma and sclerenchyma. The hydroids are elongated cells with unpitted lateral walls and oblique primary end-walls which overlap those of adjacent cells. In this respect they are similar in appearance to the hydroids described in Polytrichum except for one important difference: the lateral walls are impregnated with lignin. The hypothesis of a water conducting role is proposed for the hydroids. Lignified cells were also found in the leptome sheath surrounding the hydroids and in the inner cortical cells. Lignin is localized in the secondary walls and adjacent primary walls. The parenchyma cells of the leptome sheath which possess oblique primary endwalls may be similar to the leptoids described in Polytrichum. The high level of complexity of the gametophytic plant body among the Polytrichaceae is a well-known feature. The gametophore of Polytrichum exhibits an internal tissue arrangement which approaches that of the sporophyte of some lower vascular plants, i.e. Rhynia, Psilotum. As such, the gametophytic anatomy of Polytrichum is well-treated in the literature with particular emphasis placed on the central cylinder (Tansley & Chick, 1901; Lorch, 1931; Hibant, 1964, 1966, 1969; Eschrich & Steiner, 1967, 1968). H6bant (1964, 1966, 1969) investigated the conducting cells, i.e. hydroids and leptoids, in Polytrichum and reported that their differentiation resembled, in a number of aspects, the differentiation of the xylem and phloem in the sporophyte of vascular plants. He found conducting cells present not only in the leafy gametophore but also in the sporophyte. However, he noted one important difference between the hydroids of Polytrichum and the tracheids of vascular plants: the hydroids were not lignified. Eschrich and Steiner (1967) demonstrated that 14C-labelled assimilates move in the leptoids of the gametophore with a velocity of at least 32 cm/hr. In addition to those in Polytrichum conducting cells have been recognized in other bryophytes. Smith (1966) reported the presence of a unique water conducting system analogous to the tracheary 1Contribution No. 83 from the Department of Biology, The Pennsylvania State University. I thank Drs. Ronald A. Pursell and Charles J. Hillson for their helpful suggestions during this study and for their criticism of the manuscript, Dr. Harold Robinson for supplying the specimens used in this study, and Mr. Frank Polanowski for assistance with the fluorescence microscope. 2 The Pennsylvania State University, Department of Biology-Botany Section, University Park, Pennsylvania 16802. This content downloaded from 157.55.39.95 on Sat, 11 Jun 2016 06:18:39 UTC All use subject to http://about.jstor.org/terms 306 THE BRYOLOGIST [Volume 75 tissue of vascular plants in the liverwort genera Pallavicinia and Symphyogyna. In certain of the conducting cells actual perforations were observed. Other genera of the Polytrichaceae, e.g. Polytrichadelphus, Dawsonia, and Dendroligotrichum also exhibit a prominent central cylinder. However, little is known concerning the anatomical specialization of the gametophore in these genera. Recently, Siegel (1969) demonstrated by various extraction techniques and color reactions that lignin is a normal constituent of the gametophore of Dendroligotrichum dendroides (Hedw.) Broth., comprising up to 10% of the dry weight of the gametophytic axis. He did not investigate the anatomy of the gametophore and therefore the localization of lignin was not determined. The process of lignification has been assigned a definite role in phylogeny and has been implicated in the rise of the upright vascular land plant (Siegel, 1962). In view of this and the recent evidence of lignification in D. dendroides, I undertook this study to examine the anatomy of the gametophore of D. dendroides and to determine the localization of lignin therein. Additional studies are currently in progress which systematically treat the anatomy of other genera in the Polytrichaceae. Using comparative anatomical studies in concert with evidence from other areas, it should be possible to define more precisely phylogenetic relationships among the Polytrichaceae. MATERIALS AND METHODS Gametophores of Dendroligotrichum dendroides used in this study were herbarium specimens collected by C. F. Jardine & G. O. K. Sainsbury (s.n.) 1948, on a forest floor, ca. 3000 ft. elevation, of Mt. Manuoha near Lake Waikaremoane, North Island, New Zealand. Its distribution is limited to New Zealand and southern Chile. Intact pieces of the gametophore were soaked in water overnight, dehydrated in tertiary butyl alcohol, embedded in Tissuemat, and cut at 94 on a rotary microtome. Sections were stained with safranin O and counter-stained with fast green. In addition, pieces of the gametophore were macerated in Jeffrey's solution (Johansen, 1940) for the study of whole cells. Staining techniques used with the macerated material were: safranin O in 70% ethanol; fast green (0.5% clove oil); and the periodic acid-Schiff (PAS) reagent. The pattern of lignin deposition was determined with the light microscope by using the standard staining tests-phloroglucinol-HC1 and safranin O-and by examining the fluorescence of lignin following ultraviolet irradiation. Fluorescence of lignin was observed with a Leitz Ortholux light microscope equipped with an Osram HBO 200-w lamp; BG 12, UGI exciter filters; and Zeiss number 41, 50, and 65 barrier filters.

Mosses modify soil conditions and thereby affect the distribution of certain arthropods. Under extreme environmental conditions (such as those that prevail in Antarctica) arthropod survival and abundance often depend upon the mosses present. Several liverworts and a moss are symbiotic on New Guinean beetles, apparently conferring a degree of protection to the insects. Flies are attracted to the capsules of some Splachnaceae and disseminate their spores. Representatives of the insect o?rders Collembola, Diptera, Hemiptera, Hymenoptera, and Orthoptera, and the acarine orders Cryptostigmata and Prostigmata are known to feed on mosses. Bryophytes, along with other cryptogams, often constitute the initial stages in the plant succession series in newly colonized habitats, and it is postulated that their associated faunas form similar stages in the faunal succession. Mosses have often been studied from an ecological point of view. Among subjects of continuing interest are the role of mosses in the colonization of different land types, their succession in various habitats, and their value as indicator plants (Watson, 1964). More recently, mosses are being utilized as indicators of industrial air pollution in England (Gilbert, 1968). The associations between mosses and arthropods, on the other hand, have been largely neglected by botanical as well as zoological ecologists. The latter often ignore mosses as a habitat for arthropods. At best, this widely-occurring natural habitat is dismissed, as "it is clear that moss does not form a biotope with a stable microclimate" (Cloudsley-Thompson, 1967). The purpose of this review, which makes no pretence at total comprehensiveness is to discuss some moss-arthropod associations, and also to present a r6sum6 of my recent work on moss-feeding mites (Acarina). A full report on this study will be published elsewhere. Gadea (1964) refers to certain other moss-associated invertebrates, such as Thecamoebae, Rotatoria, Nematoda and Tardigrada, especially in high-mountain biotopes. Mosses may modify soil conditions and thus enable certain arthropods to survive better under extreme environmental conditions. Bryophytes may serve as food or 1 This review was prepared at the suggestion and with the encouragement of Dr. Robert R. Ireland, Curator of Bryophytes, National Museums of Canada, who also offered many pertinent suggestions. Dr. D. K. McE. Kevan, Chairman, Department of Entomology, Macdonald College of McGill University, reviewed the manuscript, added references, and made available hitherto unpublished information. Dr. V. R. Vickery, Curator, Lyman Entomological Museum, and Dr. D. E. Swales, Curator of the Herbarium, both of Macdonald College, also allowed me to use unpublished material. The work invested in this review was made possible by a postdoctorate fellowship from the National Research Council of Canada. 2 Department of Entomology, Macdonald College, McGill University, Ste Anne-de-Bellevue, Quebec. Pribsent address: Department of Entomology, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel. This content downloaded from 207.46.13.26 on Tue, 25 Apr 2017 17:59:37 UTC All use subject to http://about.jstor.org/terms 496 THE BRYOLOGIST [Volume 72 shelter for these animals. Insects disseminate the spores of some mosses, and certain Bryophyta have recently been found to live symbiotically on Papuan beetles. These various interactions will be discussed separately. The studies by Gressitt (1967), Strong (1967), and Tilbrook (1967) in Antarctica provide many data on the importance of bryophytes to arthropods under extremely low-temperature conditions where there is almost no other vegetation. Both Gressitt (1967) and Strong (1967) found that temperatures among mosses (Polytrichum, Drepanocladus) are consistently higher than the air temperatures just above them. Tilbrook (1967) concluded that, in the "maritime" Antarctic, Polytrichum-Dicranum mats harbor more arthropods than Pohlia mats, as the former are less wet and cold during summer. Thus, "it is felt that the mechanical structure of the bryophytes and the lichens is important in shaping the air spaces available for arthropods . . . The more open-textured mosses (Polytrichum) support arthropods to a greater depth than the more closely compact type (Pohia)." (Tillbrook, 1967.) Strong (1967) concluded that mosses provide the most extensive and variable habitat types available, differing in their suitability for various arthropods, this variability being dependent on the dominant moss. The importance of the bryophytes to the animals, according to this worker, is mostly in providing shelter from the cold and wind. The dependence of Antarctic arthropods on their local moss flora was emphasized by Janetschek (1967), who defined the bryosystem as one of the dominant antarctic ecosystems. He also noted that, with the approach to climax, mosses become increasingly important, and the entire faunal spectrum of the system is to be found in the moss tufts and mats. N0rgaard (1951) gave another example of how temperatures and humidities are modified by moss carpets and thereby affect the distribution of arthropods. Studying spider distributions in a Danish Sphagnum bog, he divided the moss carpet into two layers, the surface layer and the stalk layer. The microclimate of the former layer was very variable, daily temperature fluctuations exceeding 300C, relative humidities being between 40% and 100%. In the stalk layer the relative humidity was constantly 100% and the daily temperature fluctuation only 50C. One of the spiders studied, Lycosa pullata Clerck, lives on the moss surface, while the other, Pirata piraticus Clerck, inhabits the stalk layer. This spatial distribution is correlated with the higher temperature preference and the higher thermal death point of the former species and with the greater sensitivity of P. piraticus to low humidities. The ability of mosses to provide a humid terrestrial microenvironment may have had a part in the evolution of flies (Diptera). Oldroyd (1964) believes that these insects, as a group, have arisen from ancestors whose larvae, though terrestrial, lived in wet mosses and so had "a foot in both worlds." Several species of crane flies (Tipulidae), considered to be among the most ancestral of living fly families (Oldroyd, 1964), live in and feed on mosses, including aquatic species, and assume their green color. Alexander (1920) records Liogma spp. living on Rhytidiadelphus squarrosus (Hedw.) Warnst. (called Hypnum squarrosus Bruch & Schimp. in Alexander's monograph), Hypnum cupressiforme Hedw., and related species. Another tipulid, Triogma trisulcata (Schum.) lives in mountain streams, Where its larvae are attached to the stems of Fontinalis antipyretica Hedw. These larvae have various leaflike appendages arranged in rows on their bodies, which simulate the leaf arrangements of Fontinalis. As a result, the larvae resemble the moss on which they live to a startling degree (Alex

The mosses collected on this Expedition were submitted to me for determination, by Mr. C. G. Trapnell. They were mostly collected in the neighborhood of Isersiutilik, on the west coast, near lat. 640 N. The collection consisted of about 150 numbers, several of which included two or three species. A number of the usual arctic species predominated, e. g. Dicranum elongatum, Ditrichum flexicaule var. densum, Oncophorus Wahlenbergii, and various boreal forms of Polytrichum. Drepanocladus uncinatus was represented by much fewer gatherings than is usual from these latitudes. The greater number of the species are well known Greenland mosses, and it is scarcely worth while to enumerate these. There are however a few deserving of notice, and one undescribed species of Bryum.

In scanning electron microscope studies on the leaves of Sphagnum imbricatum Hornsch. ex Russ. comparisons between untreated and goldcoated material showed the latter preferable for observations. Pore aperture ultrastructural anatomy previously unreported upon is described. The role of differential shrinkage in the rupture of the covering membrane of hyaline cell pores is considered. Evidence for the shrinkage and furrowing of the outer walls of chlorophyllose cells as drying proceeds is also presented. Since Schimper's (1858) comprehensive treatise, comparatively little has been added to our knowledge of Sphagnum gametophyte morphology. Braithwaite (1880) surveyed the important literature to 1876. Durham (1937) studied the development of the branch leaves and the ontogeny of the hyaline cells. The majority of recent work on Sphagnum has been concerned with its taxonomy and ecology (Rigg, 1940, 1951). Relatively few electron microscopical investigations have been published on the gametophytes of the Musci. Paolillo and Reighard (1967) characterized the ultrastructural features of the green lamellae on the adaxial surface of Polytrichum and Atrichum leaves. Apparently there are no comparable studies on Sphagnum gametophytes. The topography of the Sphagnum leaf lends itself particularly well to observation by means of the scanning electron microscope. This is a newly developed research tool, which, so far as the literature is concerned, seems not to have been used on mosses. MATERIALS AND METHODS Mature gametophores of Sphagnum imbricatuum Hornsch. ex Russ. were cultured on peat moss under high humidity conditions in a terrarium exposed to morning sunlight. Voucher specimens were deposited in the cryptogamic herbarium of the University of Nevada. Material 1 The scanning electron microscope used in these studies is located in the Electronics Research Laboratory, University of California, Berkeley. Purchase was supported by NSF grant GB-6428; operation is supported by NIH grant GM-15536 and NSF grant GK-3845. 2 Department of Biology, University of Nevada, Reno, Nevada 89507. 3 Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720. FIGURES 1-4. Sphagnum branch leaves at various magnifications, all gold-coated except those in Figure 1. 1. Uncoated, untreated branch, 70x. 2. Vacuum-evaporated and goldcoated branch, 26x. 3. Enlarged view of one leaf, 65x. 4. Portion of the abaxial leaf surface above the middle, 260X. This content downloaded from 207.46.13.159 on Sat, 22 Oct 2016 04:42:01 UTC All use subject to http://about.jstor.org/terms 1969] MOZINGO ET AL.: SPHAGNUM IMBRICATUM 485

In Limpricht's Laubmoose, Band II, p. 853, the author has this note: "P. 6I8: No. 6i8. Polytrichum Ohioense Ren. et Card. in Rev. Bryol. 1885, p. ii and 12, and in Coult. Bot Gaz. XIII. p. 199, t. I7 (I888) has the priority over Polytrichum decipiens!" P. decipiens is described by Limpricht in 68. Jahresb. d. Schles. Ges. f. vaterl. Cultur 1890, II. p. 93; also in Laubmoose II, 1894, p. 6I8. In x895, in August or September, appeared the note on p. 853 of Laubmoose, above cited. This shows that at the time of that writing Limpricht considered his P. decipiens identical with P. Ohioense, reducing his name to a synonym of the latter. Then in 900o, in Bot. Centralbl. XXI. Jabrg., No. 5o, Prof. Harald Lindberg showed that the two plants are really separate, This view of the situation is honored by Limpricht in Laubmoose, Bd. III, (1903) p. 800, where he again separates his P. decipiens from P. Ohioense. While P. Ohioense appears to be exclusively North American, P. decipiens is found both in Europe and this country. Prof. Lindberg cites the following localities for P. Ohicense: Wisconsin, Milwaukee, leg. Lapham (Ex. Herb. Cardot). Lake Michigan, leg. Lapham (Ex, Herb. Cardot). Illinois, Chicago, 1888, J. R11 (No. x18I). Edgewater near Chicago, 20. 9, I888, J. Rbll (No. 18I5). New Jersey, Hoboken, 8, 1898, P. T. Cleve. Massachusetts, Milton, Blue Hill, 2, 6, 1898, 28, 8. 1898, 26. i2. I898. G G. Kennedy. District of Columbia, Rock Creek, io. 6. I894, J. M. Holzinger. Renauld and Cardot in their check list of Musci Americse Septentrionalis, p. 41, give the range of P. Ohioense as: Canada, Northern, Eastern and Central States, questionably British Columbia. The range of P. decipiens in North America is given by Lindberg as follows: "Prince Edwards Island (as P. Ohioense Ren. et Card. in Can. Musci, No. 221). To this species belongs also No. 323 in Sullivant et Lesquereux, Musci Bor. Americani, named P. formosum Hedw. Mr. Cardot refers this form in Botanical Gazette. Aug. x888, to P. Ohioense. The specimens in Musci. Bor. Am. are without locality." To this may be added a station in Minnesota, Miss Sarah O'Meara collecting near St. Charles, Winona Co., a plant the writer has referred to P. decipiens. The differences between these two species as pointed out by Lindberg in Bot. Centralbl. XXI. Jahrg., No. 50, are as follows: "P. OHIOENSE Ren. et Card.

Photosynthesis was measured in excised sporophytes of Polytrichum and Funaria with an infrared gas analyzer. Net photosynthesis was recorded for Funaria, but photosynthesis beyond the compensation point was not demon- strable for Polytrichum. The gametophytes of both genera show net photo- synthesis, and the shapes of the light saturation curves for the gametophytes are similar to those obtained for their respective sporophytes. The distribution of dry weight within the sporophyte was followed during capsule development. In Polytrichum the weight of the seta decreases as the weight of the capsule increases. This is not the case in Funaria. These results establish the importance of seta reserves in the economy of the Polytrichum sporophyte during capsule expansion. Throughout its life, the moss sporophyte remains attached to the gametophyte. It is reasonable to assume that the gametophyte contributes organic compounds to the sporophyte during part or all of the sporophyte's development. The presence of chloro- phyll throughout the young sporophyte (Bold, 1940), and especially in the capsule of the older sporophyte (Haberlandt, 1886), has prompted the question of whether or not sporophytic tissue can contribute to its own nutrition by photosynthesis. This paper is devoted to some preliminary attempts to answer this question by infrared gas analysis for the detection of photosynthesis. MATERIALS AND METHODS

POGONATUM ALPINUM (Hedw.) Roehl. Lysted Island, alt. 20-30 ft., 371.10. Lysted Island, north face, 372. Lysted Island, Chain Point, 377.5. Lysted Island, Channel Point, 378.4 Lambda Island, NE. Landing, 345.10. Lambda Island, Sevilla Landing, 348.3. Var. BREVIFOLIUM (R. Br.) Brid. Lysted Island, 335.15. Lysted Island, north face, 372.1. POLYTRICHUM SUBPILIFERUM Card. Lysted Island, 335.14. WEBER: TORTULA PAPILLOSA IN NEW MEXICO

The splitting of the inner, sheathing layer of the calyptra on the sporophyte of Polytrichum juniperinum Hedw. leads to asymmetrical expansion and the development of a capsule that is bilaterally symmetrical and dorsiventral. When unexpanded sporophytes are cultured without the sheathing layer, expansion of the capsule is radially symmetrical. When unexpanded sporophytes are cultured with the sheathing layer intact, the sheath is split and capsule expansion is asymmetrical, as it is in field-grown plants. If capsules that have already become asymmetrical are grown in culture, they develop their later angularity as would be predicted on the basis of their asymmetry. It is concluded that capsule symmetry in Polytrichum is determined by the splitting of the calyptra and the asymmetrical expansion of the erect capsule. In contrast, xThis study was accomplished with the support of National Science Foundation grant GB-6520. 2 Department of Botany, University of Illinois, Urbana, Illinois 61801. This content downloaded from 207.46.13.37 on Wed, 03 Aug 2016 05:50:58 UTC All use subject to http://about.jstor.org/terms 328 THE BRYOLOGIST [Volume 71 capsule symmetry in Funaria is determined as the capsule expands in a horizontal position and is not a function of the splitting of the calyptra. Bopp (1954; 1957a, b) studied the relationship of the calyptra to capsule expansion in moss sporophytes, with special attention to Funaria. He concluded that the calyptra exerts a mechanical restraint on capsule expansion but does not determine the bilateral symmetry of the capsule. The present study is devoted to some observations on the importance of the calyptra in Polytrichum, especially with reference to the determination of capsule symmetry. MATERIALS AND METHODS Sods of Polytrichum juniperinum Hedw. were collected at Portland Arch, Indiana, on April 10, 1968. The collections contained sporophytes with unexpanded, partly expanded, and fully expanded capsules, so that the sequence of events during capsule expansion could be reconstructed. Plants with unexpanded and partly expanded capsules were excised from gametophytes, surface sterilized for two minutes with 5% Chlorox, and planted on Voth's (1943) M5 solution solidified with 1% Difco Bacto-Agar. Unexpanded plants were cultured with and without the inner, sheathing layer of the calyptra. The culture tubes containing the plants were placed under 12 hours of daily illumination at 200 foot-candles under Sylvania Gro-lux fluorescent tubes, at 230C. Funaria hygrometrica Hedw. was obtained from the soil around potted plants in the Botany Greenhouse, on May 20, 1968, and from a border planting on the campus on May 18 and 28. Plants with capsules in various stages of development were examined, and the sequence of events in capsule expansion was reconstructed.

Field observations on colonies of Splachnum ampullaceum Hedw. in Isle Royale National Park, Michigan, and laboratory cultures maintained for three years without decline in vigor indicate a possible interrelationship between nutrient and pH factors to explain the habitual decline of colonies in nature. The genus Splachnum has a distribution in North America ranging from the northern tier of states into the Canadian provinces and to Alaska. It is also found in scattered localities in the higher meadows of the western mountain ranges in the United States. The colonies of the plant, in various states of vigor, are usually found in association with the dung of herbivorous animals, especially that of cow, moose, and caribou. This investigation was initiated to determine if factors other than nutrition might play a role in the habitual decline of the colonies. Two species of Splachnum have been collected in Isle Royale National Park, Michigan: Splachnum ampullaceum Hedw., with the characteristic top-shaped hypophysis and the splotches of purple pigment, and S. rubrum Hedw., with the umbrella-like hypophysis and the characteristic red color. They are always found in close association with moose dung in the sphagnum bogs. Splachnum rubrum is in full fruit in late June, while the fruiting period for S. ampullaceum is late August and early September. Colonies of S. ampullaceum are more common than those of S. rubrum. On Isle Royale both species appear to be most abundant in Tollman Swamp, a sphagnum bog one-quarter mile northeast of the Rock Harbor Lodge on the north end of the main island. The colonies observed in the bog were in various states of vigor. Some were pure Splachnum while others were in various stages of decline as evidenced by the presence of Polytrichum strictum and Sphagnum spp. Observations have been made of Splachnum ampullaceum under cultural conditions during a period of three years. Cultures of the moss were obtained by two different procedures: 1) from spore germination and 2) from small sections cut from mature gametophytic plants. Two types of 2% agar media were used. One was Knops medium and the other was a medium composed of distilled water with the addition of 200 cc per liter of an extract from moose dung. This extract was obtained by heating a quantity of the dung in distilled water with the temperature of the solution kept below the boiling point. The solution was decanted and added to the agar and distilled water. The cultures were grown in 500-cc, wide-mouth 1 Department of Biology, Wisconsin State University, Stevens Point, Wisconsin. This content downloaded from 157.55.39.246 on Tue, 27 Sep 2016 05:48:22 UTC All use subject to http://about.jstor.org/terms 1965] WHITMIRE: ECOLOGY OF SPLACHNUM 343 Erlemeyer flasks. The culture room was a walk-in refrigerator (500F) with three fluorescent tubes. The moss spores were dispersed over the surface of the growth medium and the flask was plugged with cotton. Germination of the spores took place in seven days. Three cultures were started and all proved successful. The small apical portions of the mature plants were first sterilized in 10% Chlorox solution to remove algal contaminants and then were placed on the surface of the agar medium. Five cultures were started. Growth continued from the apex of the plants and good regeneration of protonema and rhizoids occurred from the cut ends of all cultures except one. This failure was probably due to an excessive exposure to the Chlorox solution. Growth continued in both the spore culture and the plant culture until the entire bottom of the culture chambers was covered with mature gametophytic plants. The cultures were maintained without additional nutrient material for three years with no evident decline in the colonies. Sporophytes were produced in one of the spore cultures growing on the dung medium. These sporophytes were without the characteristic hypophysis. This does not seem to be unusual, however, since colonies in nature often produce a few sporophytes without the hypophysis. Sporophytes were not produced in the remaining cultures. There was no apparent difference in growth on the dung medium and on Knops medium. Colonies of Splachnum ampullaceum growing under natural conditions are pure after one season's growth. The second season finds encroachment upon the colonies by Sphagnum spp. and Polytrichum strictum which thrive under more acidic conditions. Three samples of fresh moose dung were found to have a pH of 6.5. Comparison of the vigor of the natural colony with that of plants in the controlled environment suggests that a lowering of the pH may cause a decline of the colonies in nature. The dung substrate undoubtedly takes on the pH characteristics of the surrounding bog. This acid condition would make it difficult for Splachnum to compete with Sphagnum and Polytrichum.

Apparent photosynthesis was measured as a function of light intensity, temperature, and CO, concentration in alpine and forest populations of Polytrichum juniperinum Hedw. The forest population showed light saturation at lower light intensities, sustained apparent photosynthesis at higher temperatures, and showed a greater response to elevated CO, concentration than did the alpine population. The achlorophyllous margins of the leaves in the alpine plants are disproportionately large compared to those in forest plants. The differences in physiology and morphology can be interpreted as adaptations to the respective habitats of alpine and forest populations. The moss Polytrichum iuniperinum Hedw. is a widely distributed species in North America. It occupies diverse habitats ranging from the alpine zone, e.g. in the New England mountains, to fairly dry scrub oak forests on sandy soils. Species of such a wide range may consist of ecologically distinct races genetically adapted to their environments or they may possess wide tolerance limits that allow them to thrive under various environmental conditions. In phanerogams both conditions occur and are very well documented. In the bryophytes, studies on ecotypic differentiation are limited. Tallis (1959) reported that Rhacoamitrium lanuginosum has variable morphology according to the site variation, and that growth rates vary with altitude, being highest at 80 m and lowest at 720 m. Forman (1964) found that leaf morphology of Tetraphis pellucida varies with temperature, being wider relative to its length at lower temperatures. In another study (Forman, 1968) he found that there was an inverse correlation in caloric values of mosses with the altitudes at which they grow. Polytrichum juniperinum from the alpine zone of Mt. Washington gave the lowest value (3951 cal) of the alpine mosses studied. There are other reports indicating that some bryophytes are able to occupy diverse habitats because of their wide tolerances. For example, Rastorfer and Higinbotham (1968) showed that Bryum sandbergii has the capacity of net photosynthesis over a wide range of temperatures and light intensities. They explain its presence in all vegetation zones of the Pacific Northwest intermountain area on the basis of its wide tolerances. Szweykowski and Vogel (1966) found that populations of Geocalyx graveolens collected at two totally different 1 This study was performed at the Department of Botany, University of Illinois, Urbana. Support for the work was furnished in part by NSF GB-6520. We also acknowledge Dr. J. S. Boyer, who furnished the gas analyzer for our use. 2 Department of Botany, University of Illinois, Urbana, Illinois 61801. 3 Section of Genetics, Development, and Physiology, Cornell University, Ithaca, New York 14850. 4 Department of Botany, University of Vermont, Burlington, Vermont 05401. This content downloaded from 157.55.39.177 on Sat, 19 Nov 2016 04:38:54 UTC All use subject to http://about.jstor.org/terms 580 THE BRYOLOGIST [Volume 73 habitats showed no significant morphological differences when grown under the same environmental conditions. For this paper we studied two populations of P. juniperinum from contrasting habitats, measuring their patterns of CO2 exchange at various temperatures, light intensities, and carbon dioxide concentrations. In addition leaf morphology and turgor movements were studied to elucidate possible relationships with the environ