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Premise of research. Climbing plants are important components of modern-day tropical forests and primarily comprise angiosperms, but in Paleozoic tropical forests, pteridosperms were the dominant c...

This paper investigates the taxonomic diversity of marattialean stems from the family Psaroniaceae preserved in-situ within the Wuda Tuff Flora. Three species of the permineralized stem Psaronius and eight species of the compression/impression stem Caulopteris are documented, but it has not been possible to associate the anatomically preserved species with the compression/impression ones due to preservational limitations. The higher diversity of Caulopteris species may relate to anatomical features that could distinguish additional species of Psaronius not being preserved, or it may reflect the rarity of anatomical preservation in the flora limiting the available dataset and it is also possible that a “generalized” Psaronius anatomy was common to several stem species showing distinct leaf scars (Caulopteris) and distinct leaves (Pecopteris). The eight species of Caulopteris recorded are very close to the previously reported diversity of nine species of the vegetative leaf Pecopteris from the Wuda flora, which also indicates a high diversity within the family. However, intraspecific variation makes the identification of species of Pecopteris and Caulopteris rather difficult, potentially inflating the taxonomic diversity of these genera. We show that Psaronius stems from the Wuda flora include one species from the Psaronius blicklei-group, one species that shares characters with both Psaronius blicklei and Psaronius panxianensis groups, and one species that shares characters with Psaronius blicklei-group but possesses a unique one different from both Psaronius blicklei and Psaronius panxianensis groups. These species appear to represent transitional forms evolved from the Carboniferous–Cisuralian (early Permian) Psaronius blicklei-group that are on the evolutionary lineage leading to the Lopingian (late Permian) Psaronius panxianensis-group. In addition, a single occurrence of a stem of Psaronius in organic attachment to a tri-pinnate frond of Pecopteris orientalis (Schenk) Pot. is documented, representing an important starting point for future Psaroniaceae whole-plant reconstructions within the Cathaysian flora.

Much is known about the biology and ecology of the plants that comprised the forest ecosystems during the Carboniferous and Early Permian. However, a broad understanding of the interrelatedness between the plants and other organisms living in these forests has been slow to develop. The tree fern Psaronius (Marattiales), an important element in many Pennsylvanian and Early Permian peat-forming forest ecosystems, gained mechanical stability from a massive root mantle. Thin sections of a permineralized Psaronius root mantle from the Manebach Formation (Asselian, Lower Permian/Cisuralian) near Ilmenau, Germany, show a diverse assemblage of predominantly intracellular fungi in all root tissues. Especially interesting is a fungus that produces prominent, boot-shaped swellings close to where it passes through host cell walls and what appear to be physiological interfaces comprised of short, densely clustered hyphal branches within the host cells. Other fungal remains occur in the form of chytrid-like sporangia, several types of basidiomycete hyphae with simple, medallion, and ampulliform clamp connections, and tenuous mycelia resembling present-day ‘fine endophytes.’ This fungal assemblage represents one of the best preserved Carboniferous-Early Permian fungal communities documented to date. It strengthens the hypothesis that plant-fungus associations were highly diverse and complex in late Paleozoic forests, likely because many plants in these ecosystems were long-lived and complex in morphology and internal organization, and thus provided multiple contact sites and ecologically distinct microhabitats for fungi.

A marattialean trunk of Psaronius laowujiensis sp. nov. is described from the Upper Permian of the Xuanwei Formation, Panxian County, Guizhou Province, South China. The specimen most likely represents the lower part of the trunk, because the preserved thickness of the root mantel is somewhat larger than the diameter of the stem. Meristeles of the stem are arranged in approximately five tangential stelar cycles but not in radial files. Inner meristeles are in small number, ∼12–13, and loosely arranged. Leaf traces diverge helically and are organized in a 2/5 phyllotaxy. The leaf base vascular configuration consists of three strands that include a large U‐shaped, centrifugal strand, a small centripetal strand, and an inverted Ω‐shaped internal strand. A vascular bundle sheath one or two cell layers thick surrounds each meristele. Within the centripetal concavity of each peripheral cauline bundle there are anchor‐shaped sclerenchymatous strands. Ground tissue appears to consist of aerenchymatous parenchyma, ...

A new species of the marattialean fern trunk Psaronius Cotta is described from the Upper Permian Cathaysian flora in the Xuanwei Formation of Guizhou Province, SW China, and named P. panxianensis sp. nov. Stems possess a helically diverging sequence of leaf traces organized in a 2/7 phyllotaxy and are characterized by stages of leaf trace development that include an early ontogenetic stage with a single vascular bundle (Stewartiopteris-type), a middle stage with two vascular bundles (Stipitopteris-type), and a late stage with three vascular bundles. Roots diverge singly or occasionally in pairs, arising alternately from the centrifugal surface of the peripheral cauline bundles (PCB) near the tip, and form both bound and free root mantles. This species is distinguished from all previously recognized species from the Euramerican and Gondwana floras in having an anchor-shaped sclerenchymatous strand internal to the PCB and a large V-shaped strand formed by the connection of two anchor-shaped strands. Psaronius panxianensis sp. nov. is important as its leaf traces show three distinct ontogenetic development stages within the trunk, with this organization interpreted as a derived condition within psaroniaceous marattialean fern evolution. In the stem abundant air space suggests that P. panxianensis lived in waterlogged substrates with aerenchyma facilitating gaseous exchange. However, the presence of marattialean fern dominated communities in the Upper Permian of SW China suggest an overall drying trend with these plants replacing earlier lycopsid and sphenopsid dominated wetland communities.

The Tedeleaceae are late Paleozoic Filicalean ferns with two known genera, Ankyropteris and Senftenbergia, which partially overlap morphologically and have the same known stratigraphic ranges—Namurian A to Lower Permian in Euramerica. Ankyropteris is anatomically known and Senftenbergia is almost exclusively based on compression specimens. Both genera exhibit abaxially, laminar-borne sori and/or solitary sporangia with some schizaeoid attributes. The sporangia are pyriform to tear-drop shaped, erect to slightly curved with a two to multiseriate apical annulus and mature spores usually of the Raistrickia type. Detailed morphological comparisons of Ankyropteris with Senftenbergia emphasize generic overlaps as well as lack of congruence. Ankyropteris brongniartii, a classic vine in anatomy, defines the stratigraphic range of the genus and provides recurrent ecological observations of habit and associated plants in ecotonal swamp reaches as well as in volcanic environments and on other clastic substrates. Ankyropteris may have originated from the clepsydroid zygopterid clade outside of the swamps. Ankyropteris brongniartii occurred as an epiphytic vine on Psaronius tree ferns as they expanded into coal swamps and often co-occurred with Paralycopodites even earlier in Middle Pennsylvanian. Vine stem anatomy and functional morphology of aphlebiae are emphasized in A. brongniartii with comparisons to Austroclepsis, an early “vining” false tree fern. Anatomical comparisons of Ankyropteris species based on shoots emphasize divergent habits with similar robust sizes; all exhibited aphlebiae. Known only from coal balls, Ankyropteris corrugata (Westphalian A–B) had a rampant habit on exposed peat with a succulent, dichotomous rhizome and erect fronds. The Lower Pennsylvanian specimen of Ankyropteris hendricksii is a compact tree fern with crowded frond bases and intercalated roots. Tyloses commonly occur in A. corrugata and A. brongniartii indicating water-stressed conditions. Apical meristems of shoot and fronds are reported for the first time, suggesting response growth to disturbance and rapid burial.

New specimens of Botryopteris Renault deriving from the Permian of the Maranhao Basin (NE Brazil) are both the first evidence of this palaeozoic fern group from the Southern Hemisphere and the youngest known to date. These remains cannot be assigned to any known species of the Botryopteridaceae. Therefore, the new species Botryopteris nollii sp. nov. is established. One of the most conspicuous characters of this new fern is the ability to grow in different forms. Firstly, it has been found rooted within the marginal trunk base of the tree ferns Grammatopteris freitasii Rosler and Galtier and Psaronius brasiliensis Brongniart. Secondly, cauline organs, foliar members and adventitious roots of this fern formed a compound system of a so-called false trunk. This results from the formation of closely spaced spirally arranged foliar members of different order on upright stems and of the repetitive development of shoots from foliar-borne buds inside the trunk. The newly collected material is preserved as silicified permineralisation, and therefore allows to recognise characters of vegetative morphology but also details of the anatomy and internal organisation. Botryopteris nollii sp. nov. is characterised by nearly circular protostelic stems and stipes/rachises that show a dorsiventral ω-shaped vasculature. The new fern underlines the striking growth form diversity seen in the whole family Botryopteridaceae.

Stimulated by new observations, this contribution presents a summary of the current knowledge of different plants that grew closely associated with Psaronius trunks in the Early Permian petrified forest of Chemnitz (Saxony, Germany). The role of Psaronius tree ferns was to provide a frequently-used substrate for colonisation by other plants. The massive root mantles protected different developing plants, and they may have improved the possibility of preservation of smaller plants and plant organs in particular. These are climbing axes of the fern Ankyropteris brongniartii , small epiphytes of the fern Tubicaulis sp., different isolated petioles of the fern Anachoropteris , small ? Grammatopteris axes, roots of the pteridosperm Callistophyton , and Dadoxylon specimens representing Amyelon roots of Cordaites and conifer stems. Further, plant-animal interactions demonstrate the role of Psaronius as an ecosystem unto itself.

International audience; A new species of permineralised marattialean fern trunk is described from Lopingian (late Permian) aged volcaniclastic tuffs from Panxian County, western Guizhou Province, China and named Psaronius xuii sp. nov. The stem has vascular bundles that are encircled by a bi-layered sheath and has a ground tissue consisting of thicker-walled and thinner-walled parenchymatous cells and dispersed nests of sclerenchymatous cells. Two sclerenchymatous strands occur between neighboring stelar cycles, with this species lacking a peripheral sclerenchyma sheath and possessing a "chrysanthemum"-shaped sclerenchyma strands in the adaxial bay of the peripheral vascular bundles. Although distinct from other species, comparisons demonstrate a consistent organisation amongst contemporaneous species from South Cathaysia that have sclerenchymatous strands in the adaxial bay of the peripheral vascular bundles, vascular bundles and leaf traces surrounded by a vascular bundle sheath, and the middle part of the leaf trace is depressed inward after departing from the peripheral vascular bundle. These features are used to define the Panxianensis Group named after the most comprehensively known species, P. panxianensis. Species within the Panxianensis Group differ from other species from the Carboniferous and Permian floras of Euramerica, Gondwana and North Cathaysia that we place in the Blicklei Group that lack sclerenchymatous strands in the adaxial bay of the peripheral vascular bundles, lack vascular bundle sheaths, and the middle part of the leaf trace is arched outwards when they depart from the peripheral vascular bundles. Members of the Panxianensis Group appear to represent a relatively derived group that appears to be endemic to South Cathaysia, with these presumably evolving from members of the Blicklei Group in the Cisuralian or Guadalupian

We document the presence of the piercing-and-sucking functional feeding group and the dietary targeting of vascular tissue (phloem and xylem) in marattialean tree-fern rhachises from a Late Pennsylvanian (302 Ma) coal-swamp forest in the Illinois Basin. Our evidence originates from permineralized peat that exhibits cellular-level preservation of tissues from whole Psaronius tree-fern rhachises; it includes 3 stylet probes, each of which traverses epidermal tissues and parenchyma, and terminates in a distinctive feeding cavity within phloem and xylem of a vascular strand. The stylet probes are lined with an opaque, sheathlike material, and are principally intracellular, although large gum sac cells are avoided. One of their most diagnostic features is 1 or 2 ridges occurring on the inner surface of each stylet probe, paralleling most of the probe length. These ridges, documented by light and scanning electron microscopy, are interpreted as host tissue casts of interstyletal sulci. From these and other features of stylet-trace morphology, we conclude that the herbivore was an insect of the order Palaeodictyoptera rather than an hemipteroid insect. Well developed reaction tissue surrounding the stylet trace developed while the plant host was alive, demonstrating herbivory. Previous studies have documented piercing-and-sucking in several examples of plant damage from the Early Devonian to Late Pennsylvanian (395–290 Ma). The oldest credible examples are plant lesions indicating piercing-and-sucking arthropods from 2 Lower Devonian deposits. We hypothesize that in later Middle Pennsylvanian, equatorial, coal-swamp forests of Euramerica, the dominant arborescent plants possessed vascular tissues largely unavailable to insects, because they were either deeply embedded in thick cortical tissues or protected by outer indurated, peridermal tissues. Subsequent tree-fern forests of the Late Pennsylvanian provided accessible vascular and other tissues to surface-dwelling insects with stylate mouthparts–a condition which continued into the Permian and propelled the hemipteroid radiation.

ACL-11-04; International audience; Psaronius housuoensis sp. nov. is described from the Upper Permian Xuanwei Formation deposits of Housuo Coal Mine, Fuyuan County, Yunnan Province, southwest China, adding to the marattialean fern community of the Cathaysian flora. The permineralized stem shows a polycyclic dictyostele with five leaf traces arranged in a helical manner and exhibiting 2/5 phyllotaxy. Vascular bundles arranged in 6 concentric rings with cauline bundles in 5 radial rows. Stem bound externally by a peripheral sclerenchyma sheath. Leaf trace configuration comprised of three vascular bundles resulting from the division of a single originally C-shaped strand. Ground tissue replaced with coprolites and sediments. Stem surrounded by a thick mantle of roots. Occurrence of coprolites within the stem indicates well developed plant-animal interaction during the Late Permian times and that the habitat in which Psaronius grew was abounding with diversity of arthropod or the oribatid mite community preferring the rotting P. housuoensis sp. nov. stem ground tissue as a suitable microenvironment for shelter. Evolutionary pattern of leaf trace development is described in the new species and its possible ecological significance.

Basal parts of Botryopterisforensis have been discovered rooted within the mantle of the tree fern Psaronius. Specimens occur in Upper Pennsylvanian coal balls from near Steubenville, Ohio, USA. The Botryopteris stems branch profusely, and these shoots are intertwined with the Psaronius roots near the surface of the mantle. They also produce adventitious roots that extend among the Psaronius roots. This material demonstrates that B. forensis was a trunk epiphyte, rather than a rhizomatous terrestrial fern. The B. forensis plant is interpreted to have branched continuously, to ramify, and to maintain itselfat the periphery ofthe growing mantle of Psaronius roots. A new reconstruction of B. forensis is offered showing the large, globose fructifications hanging pendulously from horizontal fronds on emergent shoots. Epiphytes and lianas are common on the trunks of Psaronius, indicating that some Marattiales did not produce leaf skirts.

Psaronius Cotta is one of most widespread and well known fossil generic names established for permineralised stems showing anatomical structure (Goppert in Nov. Actorum Acad. Caes. Leop.-Carol. Nat. Cur. 17(Suppl.): 456. 1836; Brongniart, Hist. Veg. Foss. 2: 56. 1837 & in d’Orbigny, Dict. Univ. Hist. Nat. 13: 94. 1849; Schimper, Traite Paleontol. Veg. 1: 716. 1869; Scott, Stud. Foss. Bot., ed. 2, 1: 296. 1908; Seward, Foss. Pl. 2: 412. 1910; Gothan in Potonie, Lehrb. Palaobot., ed. 2: 109. 1919; Hirmer, Handb. Palaobot. 1: 545. 1927; Posthumus, Cat. Foss. Fern Stems: 146. 1931; Darrah, Textb. Palaeobot.: 141. 1939 & Princ. Paleobot.: 96. 1939; Reed in Bot. Gaz. (Crawfordsville) 110: 506. 1948; Stidd in Palaeontographica, Abt. B, Palaophytol. 134: 87. 1971; Mickle in Illinois State Mus. Sci. Pap. 19: 1. 1984; Herbst in Ameghiniana 21: 243. 1985; Rosler in Rev. Palaeobot. Palynol. 108: 55. 2000; Hilton & al. in Geol. Mag. 141: 661. 2004; Taylor & al., Paleobotany: 418. 2009). In addition, the generic name provides the type of a distinct fossil fern family Psaroniaceae F. Unger (in Endlicher, Gen. Pl. Suppl. 2: 4. 1842 (‘Psaronieae’)), order Psaroniales Barthel (in Abh. Staatl. Mus. Miner. Geol. Dresden 24: 37. 1976) and suborder Psaroniineae O. Feistm. (in Palaeontographica 23: 151. 1874 (‘Psaronieae’)) [vide Doweld, Prosyllabus: vii. 2001]. In 1845, after careful studies of original Sternberg’s fossil material, Corda (Fl. Protogaea: 94. 1845) came to conclusion that Scitaminites Sternb. should be synonymized with Psaronius Cotta due to their essential similarity in anatomical structure. Although the priority of Sternberg’s name was obvious even in these earlier times, a consensus was reached to keep the junior name Psaronius Cotta in current use, while recognizing Scitaminites Sternb. as a rejected synonym (Presl in Abh. Bohm. Ges. Wiss., ser. 5, 4: 288. 1847; Goppert in Bronn, Index Palaeontol.: 1050. 1848; Brongniart in d’Orbigny, Dict. Univ. Hist. Nat. 13: 94. 1849; Unger, Gen. Sp. Foss.: 216. 1850; Renault, Cours Bot. Foss. 3: 142. 1883; Kidston in Trans. Geol. Soc. Glasgow 9: 39. 1889; Potonie, Lehrb. Palaobot.: 70. 1899 & in Engler & Prantl, Nat. Pflanzenfam. Abt. 1, 4: 509. 1900). Scitaminites Sternb. was used only three more times in its history (Goppert, l.c. 1836; Brongniart, l.c. 1837; Presl in Sternberg, l.c. 2: 173. 1838) and disappeared completely from the botanical literature from 1845. Therefore, in order to legitimize the established use of Psaronius in current systematic botany, it is proposed to conserve this generic name against Scitaminites Sternb. As an addition to the Taxonomic Literature II database, the exact publication date of the book of Cotta (l.c.) was established via weekly bibliographical lists of all newly published books in German states, Bibliographie von Deutschland oder Wochentliches Verzeichnis aller in Deutschland herauskommenden neuen Bucher, Musikalien und Kunstsachen (Leipzig), no. 5, 10 Mar 1832, p. 35 (# 298), the range of dates reflecting the interval between the issuance of consecutive weekly numbers (3–10 Mar 1832).

Carbon allocation to different tissues and organs of Late Pennsylvanian-aged coal-swamp plants was determined for the first time through study of coal balls from the Calhoun coal of central Illinois. Coal balls are concretions that preserve the original peat fabric of the coal seam; they occur within the coal matrix and generally are permineralized with calcium carbonate. Coalified plant cell walls are preserved within the mineral matrix of the coal ball, entombed within the calcium carbonate. Relative carbon allocation was determined by separation of the mineral matrix and organic carbon. Carbon content was determined for replicates of tissues or organs of Psaronius tree ferns, Medullosapteridosperms, the lycopsid Sigillaria approximata, the small fern Botryopteris forensis, and "whole peat'. Unit volume results for tissues and organs were normalized for trunk sections 45 cm in diameter and 1 m long. Psaronius tree ferns were significantly "cheaper" than all other plants due to the large mantle of aerenchymatous roots that made up the bulk of the trunk. Medullosans and small ferns were most "expensive", with the arborescent lycopsid in between. Relative expense of construction closely parallels the inferred ecological role of each plant within ancient coal swamps, deduced from distributional patterns and indicators of habitat conditions. Tree ferns and lycopsids are colonists, medullosans are site occupying forms.

Coprolites composed of plant debris are common in Pennsylvanian-age coal balls. However, the coprolites themselves given no indication as to whether they were produced by herbivores or detritivores. In this report evidence that certain coprolites were produced by a highly specific kind of herbivore is presented. Many petioles of the marattialean tree-fern Psaronius chasei from the Calhoun Coal (Upper Pennsylvanian) of Illinois have large cavities filled with coprolites and disrupted plant tissue. The cavities are bordered by extensive proliferation of the cortical parenchyma. This proliferation closely resembles wound tissue produced by extant ferns and occurs only in petioles with coprolites. The cylindrical coprolites averaged 1.85 by 2.76 mm and are composed of the remains of plant tissues including sclerenchyma, gum sacs, and other cells identifiable as tissue from the petioles in which the coprolites occur. The plant-animal interaction represented by the wounded petioles is highly specific. No evidence of it has been found in any other kind of petiole (e.g., seed fern) or even in petioles of other species of Psaronius. Only petioles larger than 1.5 cm in diameter have wound tissue and coprolites.

A new species of Psaronius is described from permineralized monocyclic stems with distichous leaf scars. Diameters for the steles are 3.5–4.4 cm, up to 6.5 cm for the stem, and 8 cm for the trunk which includes inner and outer roots; the longest of 11 specimens is 32 cm. These specimens from the lower Pennsylvanian of western Illinois are the oldest known histologically preserved stems and roots for the genus. Psaronius simplicicaulis sp.nov., with its distichous leaf arrangement, is very similar to Mississippian – early Pennsylvanian Megaphyton specimens, indicating that the earliest known marattialean tree ferns were smaller in diameter than their late Pennsylvanian relatives and probably monocyclic with distichous fronds. The middle Pennsylvanian increase in the distribution and abundance of Psaronius generally coincides with increased size, polycyclic stelar anatomy, and polystichy.

Description anatomique detaillee du phloeme des tiges, de differents specimens de Psaronius, et comparaison avec la structure de phloeme des membres existants de Marattiales

Telangium pygmaeum Graham is known from Upper Pennsylvanian coal balls from the Calhoun coal mine (Illinois). The species was described as possessing radial synangia consisting of 3-5 sporangia fused laterally for about 1/3 their length. Synangia were believed to be sessile and borne terminally or laterally on a branching rachis without lamina. Examination of new coal ball material of the same age indicates that the synangia are borne abaxially on the pinnules of a compound frond with the anatomy of a Psaronius leaf (Marattiales). Synangia are sessile and borne in two rows, one on either side of the pinnule midrib, under the unbranched lateral veins. Synangia are radial, 0.6 mm in diam, and consist of a ring of thin-walled sporangia fused to near their apices prior to dehiscence, but separating on dehiscence to release spores along their inner midline. Spores are spherical, trilete, 30-48 ,um in diam, with a granulate ornamentation. The new genus Araiangium is proposed for this material based on the organization of the sessile thin-walled synangia. Araiangium is compared with other marattialean genera with sessile synangia (Acaulangium, Acitheca), and with the pedicellate synangia of various species of Scolecopteris. Criteria used in the delimitation of genera in Paleozoic anatomically preserved marattialean fertile foliage are discussed. TELANGIUM PYGMAEUM GRAHAM (1934) is a portion of a fertile coal ball plant from the Upper Pennsylvanian of Illinois. The generic name implies that it is a pollen organ belonging to the lyginopterid seed ferns, and was described as consisting of sessile radial synangia borne on a naked branching system. Specimens of Telangium from the Upper Mississippian have

Criteria are provided for identification of certain Pennsylvanian-age plant megafossils directly from coal based on their characteristic anatomical structures as documented from etched polished coal surfaces in comparison with other modes of preservation. Lepidophloios hallii periderm, Diaphorodendron periderm, an Alethopteris pinnule, and a Cordaites leaf were studied in material in continuity with adjacent permineralized peat (carbonate coal-ballas). Calamites wood in attachment to a pitch cast and a Psaronius stem in coal in attachment to a fusinitized Psaronius inner root mantle were studied. Sigillaria was identified in coal by comparison to its structure in permineralized peat. Other plant tissues with characteristic structures were found but could not be attributed to specific plants.

Numerous specimens from several species of the Paleozoic marattialean fern genus Psaronius Cotta were collected from Upper and Middle Pennsylvanian deposits in Ohio, Illinois, and Kansas. I suggest that, as the Psaronius plant grew, basal portions of the stem and bound root zone decayed. This conclusion is based on specimens in which the stem and bound root zone are completely or partially lacking, the paucity of very basal trunk segments known for the genus, and evidence from living analogs. Secondary parenchyma in P. chasei Morgan and P. blicklei Morgan is described as localized areas of radially aligned cells in stems and outer cortex. Linear regressions of number of orthostichies, stelar cycles, and inner meristeles versus stem diameter indicate that vascular ontogeny may have occurred at different rates among some species of Psaronius. Analysis of Psaronius stem anatomy and morphology suggests that, in general, stems had an open, unidirectional growth mode with a continuously expanding apex and vascu...

1. A well-preserved silicified specimen of the genus Psaronius, showing both the internal anatomy and the external features of Caulopteris, is described (as P. cooksonii) from the Kansas Wabaunsee group, Upper Pennsylvanian. 2. Anatomically, it is characterized by twelve foliar bundles alternating with twelve peripheral bundles. The leaf scars are in twelve vertical rows arranged in alternating whorls of six leaves each. Evidence is presented to show that the pattern of the leaf trace scar varies (depending on the distance from the base of the petiole) from a straight band to a U-shape, then to an oval-shape, and finally to an oval with an inclosed inverted V. It is also pointed out that when the Caulopteris surface is free from the usual sheath of adventitious roots, the leaf vascular bundle scar is visible only as a slightly curved band within the base of the protruding petiole scar, its higher configurations being simulated by the fissure between inner parenchyma and outer sclerotic zones of the petiole.

HALL, JOHN W. (U. Minnesota, Minneapolis.) Anachoropteris involuta and its attachment to a Tubicaulis type of stem from the Pennsylvanian of Iowa. Amer. Jour. Bot. 48(8): 731-737. Illus. 1961.-Petioles referable to Anachoropteris involuta are described, attached to a stem which most nearly corresponds to a member of the genus Tubicaulis. These petioles are attached in a 2/5 phyllotaxy. At their points of departure petiole traces are massive and C-shaped but become involute in regions away from their attachment. Adventitious roots were borne on the stem in partial whorls. It is suggested that 4nachoropteris petioles were extremely long and that they bore adventitious stems at intervals. These, in turn, bore adventitious roots, perhaps to serve for uptake of minerals or support in regions removed from the true stem. Such a "petiole unit" may also have functioned as a vegetative propagule. This would account for the apparent rarity of true stems and the abundance of petioles in coal balls. ALTHOUGH one of the less conspicuous elements of the Paleozoic vegetation, the coenopterid ferns nevertheless occurred in great variety. Two incompletely or inadequately known form genera of this group are Tubicaulis and Anachoropteris. Tubicaulis is a generic name assigned to protostelic stems to which are attached baror C-shaped petiole traces in a 2/5 phyllotaxy; except for their bases, where attached to the axis, the leaves of Tubicaulis are unknown. On the other hand, Anachoropteris is a genus which includes petioles whose xylem traces are more or less involutelv coiled, with the bar portion of the trace presumably on the adaxial face of the petiole. These petioles are not infrequently encountered in coal balls, but there has been only 1 account of either fructifications or foliage laminae attached to supposed Anachoropteris petioles (Kubart, 1916). The axis to which petiales of the Anachoropteris type were attached is unknown, but there have been suogestions that Tubicaltlis or Tubicaulis-like stems did bear Anachoropteris petioles (cf. Delevoryas and Morgan, 1954). In no specimen of Tubicaulis thus far recorded have the petiole traces been involute, in typical Anachoropteris fashion. Delevoryas and Morgan (1954) have discovered petioles of A, clavata to which are attached small, terete, stem-like axes. But for other species of Anachoropteris, no principal axis has been discovered. Tubicaulis is represented by 6 species, 3 known from Europe, 3 from the United States; 2 growth habits are represented in this genus: an erect, perhaps somewhat shrubby habit, and the scan;dent habit. From this country, T. multiscalariformis Delevoryas and Morgan (1952) and T. stewartii I Received for publication March 6, 1961. Support for this publication was provided by grant G944 from the National Science Foundation. Appreciation is expressed to Chr. Westergaard, Danish Geological Survey, who made the photographs. Eggert (1959) are erect, and T. scandens Mamay (1952) is an epiphyte on a trunk of Psaronius. There are relatively few specimens of Tubicaulis known; 2 of the American species are based on single specimens. Anachoropteris is much commoner than Tubicaulis and many species are known. A. involuta Hoskins (1930) is particularly common in this country. The stem to be described here is essentially a Tubicaulis stem, but petioles of the Anachoropteris involuta type are attached to it. It is convenient in the following description to refer to the stem as Tubicaulis and to the petioles as A. involuta. The stem does not correspond to any of the species of Tubicaulis thus far described. This stem is from a coal ball collected at the Carbon Hill coal mine near Oskaloosa, Iowa, which is in the Des Moines Series of the Middle Pennsylvanian. The coal ball was relatively small and oblate, and the axis lay obliquely to its long axis. Since the coal ball was cut at right angles to its long axis the stem was originally cut somewhat obliquely; subsequent cuts partially corrected the obliquity. The ends of the stem, at the margins of the coal ball, were pyritized and not well preserved. In spite of its small size the coal ball contained numerous plant fragments, mostly leaves, cones and seeds of Cordaites. Delevoryas and Morgan (1952) suggested a semisubterranean habit for T. multiscalariformis, partly on the basis of lack of associated extraneous material. It would appear likely that the present stem was an aerial segment which was transported and deposited with the other associated aerial plant fragments; neither apex nor base was preserved. DESCRIPTION OF THE SPECIMEN-The stem was probably sub-elliptical in outline, but Fig. 1, 2, 10, 11 appear elliptical because of a slight obliquity to the sections and because the specimen has been

1. Some isolated vegetative fragments of two groups of Carboniferous plants, Sphenophyllum and Psaronius, are described. The fragments are from different sources, from Indiana, Illinois, and Texas, but all are from coal fields which were said to be part of the Allegheny formation of the Pennsylvanian system. 2. The Sphenophyllum fragments consist of stem tips, their associated leaves, and small portions of two mature stems. One of the mature stems is noteworthy for its exceptional size, measuring 1.5 cm. in diameter, which makes it one of the largest, if not the largest, on record. This stem also possesses irregularities of growth simulating growth rings. 3. A review of the anatomical features of the different regions of Sphenophyllum leads to the belief that the plant was of a trailing or scrambling (lianoid) habit. 4. Adventitious rootlets from two regions of Psaronius are described: (a) young rootlets from the upper region of the stem, where they are crowded and held together by interstitial tissue, ha...

1. This paper records the occurrence of a number of plants found as petrifacts from Calhoun coal mine, Richland County, Illinois. The plants belong to the genera Calamites, Sphenophyllum, Lepidodendron, Lepidostrobus, Sigillaria, Mazocarpon, Botryopteris, Anachoropteris, Psaronius, Heterangium, Myeloxylon, and Cardiocarpus. 2. It appears that there are no constant anatomical distinctions between the Eu-Sigillariae and the Sub-Sigillariae. 3. The branching of petioles of Botryopteris americana is described.

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A B S T R A C T The basal stem anatomy of three young sporophytes of Psaronius from the Middle Pennsylvanian of Kansas and Illinois is described. The origin of the second stelar cycle is demonstrated in the transition from a simple, amphiphloic siphonostele to a dicyclic dictyostele. Petioles with C-shaped vascular strands are attached to the stem in a one-third phyllotaxy. A root mantle is lacking. Basal stem anatomy of Psaronius is compared with that of living genera of the Marattiaceae. ONTOGENETIC approaches to the study of Pennsylvanian-age plants have greatly increased our understanding of the arborescent lycopods, calamites, seed ferns, and tree ferns. Although some fossil apices have been described, the fragments usually represent more mature parts of the plaint, and in many cases secondary growth has further modified the plant body. These studies have been reviewed in detail by Delevoryas (1964). For the first time small, young sporophytes of Psaronius, a marattiaceous tree fern, have been discovered with attached petioles in Pennsylvanian-age coal balls from Illinois and Kansas. Some of the earliest ontogenetic stages of the vascular system are described below.

1. A morphological study of four specimens of the Paleozoic tree fern Psaronius was made. These specimens were placed in the following three species: Psaronius septangulatus Gillette, P. peoriensis Gillette, and P. giffordi Potonie. P. sepiangulatus and P. peoriensis possessed seven rows of leaves arranged spirally; P. giffordi possessed six rows of leaves arranged in two whorls. 2. The vascular anatomy of one of the specimens of Psaronius septangulatus was studied in detail from a series of transverse sections of the stem. The leaf traces diverge outward from the center of the stem axis in a manner somewhat similar to that described for P. infarctus, which possessed whorled leaves. 3. Thin sections of all three species were examined and described for the different tissue types.

After referring to the remarkably uniform character of the order of Ferns throughout their whole history on the globe, the author pointed out that there existed in the Coal-Measures two very distinct kinds of fern-stems, each represented by several species. Both of these were very different from the Chelepteris -group already described by the author in the Journal of the Society. The first group had a stem-structure like that of living tree ferns. In them the vascular elements of the stem formed a close cylinder round the pith; and the vascular bundles for the leaves were given off from the out-turned edges of the cylinder, where, at regular intervals, corresponding to the position of the leaves, narrow meshes occur for this purpose. To this group were referred the stem described by Lindley and Hutton as Caulopteris Phillipsii , and several hitherto undescribed species from Radstock and Newcastle. No materials had yet been detected which could throw any light on the foliage or fruit of these fern-stems. The second group included some stems the casts of which the author had obtained from Radstock, and the root-structures from Halifax. By the help of a fine series of specicimens in the collections of the British Museum, he was able to correlate the different parts of these plants. The stems had been described by Corda under the name of Stemmatopteris . They differed from the other group chiefly in having the ends of the vascular plates, as seen in the transverse section, turned inwards, and having the bundles of the leaves formed in a complete condition in the axis of the stem. The author showed that the relation of the different parts of the stem in the species of Caulopteris was tile same as in a first year9s dicotyledon; while in the latter group the analogy of the structures was with the monocotyledonous stem. The roots, which surrounded the older portions of the stem, formed the well-known genus Psaronius , of Cotta; and as this was the earlier name, it was proposed to retain it for the genus. There was associated with all the fine specimens of this group, which the author had received from J. M9Murtrie, Esq., F.G.S., foliage which had been described as Cyatheites arborescens . Although this had not been observed organically connected with the stems, the author adduced several reasons for believing that it belonged to them. If this connexion could be established, it was of the greater importance, as this form was known in fruit; and the fruit established that its affinities were with the living Alsophilas and Cyatheas. Many species of this genus occurred in the continental coal-fields; but the author believed that all the specimens found in England, though differing considerably amongst themselves, belonged to a single species.