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Germination of Rumex acetosella L. was studied under a variety of experimental conditions to determine whether populations from old fields of different ages (fallow for 6 months to 15 years) differed in seed weight and germination rate and in plant biomass and flowering rate of the resulting plants. Fresh seeds collected from these natural populations showed differences in germination that varied with the date of harvest and the number of years since the field was last cultivated: seeds of the youngest population harvested in July germinated the best and were lighter than those of the other populations. Different fertilizer levels applied during the growth of the mother plants from seeds collected in the original old fields affected the mean weight and the germination rate of the resulting seeds, regardless of the density of cultivation of the mother plant. However, the effect of different fertilizer levels on mean seed weight varied with the origin of each population. Heavy seeds (mean weight > 0.6 mg) of mother plants from the populations of fields abandoned over 2 years ago germinated better than light seeds (mean weight

The low-altitude parts of the Upper Clutha have the nearest to a continental climate in New Zealand, with little-described vegetation comprising a mixture of native and exotic species. The vegetation ranges from remnants of Kunzea ericoides woodland to a “semi-desert” with bare soil between mats of scabweed (Raoulia australis). A vegetation survey was made, and the vegetation summarised for convenience by Cluster Analysis into eight major communities. The “Salix” community occurs in the wettest sites. Other wet sites had a variety of vegetation, and are categorised as “Wet Miscellaneous”. “Dactylis/Cirsium pasture” includes agricultural pasture plants and weeds. Three drier communities can best be characterised overall by the presence of Rumex acetosella and Vulpia megalura. The “Verbascum/Thymus/Rumex” community tends to have present one or more of V. thapsus, T. vulgaris and R. acetosella. It tends to occur at lower altitude than the following two communities, and on east-facing aspects. The “R...

The family Polygonaceae consists of some 40 genera with ca. 800 species. Its distribution is cosmopolitan, but chiefly in the northern temperate regions. The Polygonaceae are of special interest as some of its members are grown as crops (e.g. Fagopyrum esculentum, Rheum officinale), while others are well-known weeds (e.g. Polygonum aviculare, Rumex acetosella). According to Nowicke and Skvarla (1977) the Polygonaceae is one of the most eurypalynous families among the dicotyledons.

Callus cultures were established from dioecious plant species Rumex acetosella and R. acetosa, using cotyledons, hypocotyls and stem tips of aseptically germinated seedlings as primary explants. Cultures were also established from male and female R. acetosella adult plants, starting from vegetative lateral buds. Cell division was induced using a high 2,4-D concentration, while bud induction and multiplication were stimulated on a medium with high BAP/IAA ratio. Cotyledon fragments of both species produced only rhizogenic calli. Hypocotyl-derived calli of R. acetosella produced buds, while those of R. acetosa showed no bud forming response under these conditions. Bud multiplication occurred in stem tip cultures of both species and in lateral bud cultures of R. acetosella. Calli derived from male plants produced more buds than those from female. Shoots were easily rooted using IBA, and plantlets were effectively transferred to soil. Flowering was not induced in culture. The sex of regenerated male and female plants was not altered by the culture conditions.

SUMMARY The present paper is a sequal to similar ones dealing with populations in Belgium and France. About 80 population samples were gathered in the following areas: the southern part of the German Federal Republic, the Swiss, Austrian and (partly) Italian Alps, and northern Austria. Of these samples the occurrence of angiocarpy vs. gymnocarpy and the chromosome numbers were determined, special attention being paid to the incidence of foliar multifidy. In the Alpine region proper the large majority of the individuals is gymnocarpic. In southern Germany and Lower Austria the plants are nearly always angiocarpic, however. The distribution of the levels of ploidy is rather intricate and roughly as follows: gymnocarpic diploids occur in the southernmost French Alps, in the southern and western Swiss Alps, and in a single population in the Austrian Wachau on the NE escarpment of the Alps; gymnocarpic tetraploids in the Austrian Alps, and rather numerous hexaploids, with some angiocarpy, in the intervening border area of the central Alps. In southern Germany and Lower Austria mostly angiocarpic hexaploids were encountered, with predominantly gymnocarpic tetraploids especially in the border area between Austria and Czechoslovakia (the Bohemian Forest). In the latter region hybridisation between tetra- and hexaploids frequently takes place. There are correlations between this chorological pattern and certain consistent phytogeographical phenomena in the Alpine region associated with its Pleistocene geological history, such as the presence of several refugia and the so-called Rein-Traun gap in the central Alps. In addition it is suspected that antropogenous influences have disturbed the original situation to an appreciable extent. The degree of dissection of the leaves, as a character included in the population analyses for the first time, is present to the same extent in alpine di- and tetraploids (in which the leaves are more or less multifid), but in the Alpine and the German and Lower Austrian hexaploids, foliar multifidy is hardly developed. Some possible causes and plausible conclusions are discussed. The single population in the Wachau refugium contains a singularly high percentage of plants with multifid foliage and this is, among other things, the reason why this population is considered to belong to a different population complex than do the Alpine ones. In the discussion some space is devoted to difficulties that may be expected if a future, novel taxonomic classification of the complex is attempted.

SUMMARY Seeds of 14 species were collected, usually in each of 2 or 3 yr, and mixed with the top 7.5 cm of sterilised soil confined in cylinders sunk in the ground outdoors and cultivated three times yearly. Seedling emergence was recorded for at least 3 and usually 5 yr. Most seedlings of Ranunculus bulbosus and Rumex acetosa appeared during the autumn of sowing, while the main emergence of Geranium pratense. Ranunculus acris, Rumex conglomeratus and R. maritimus was in the following spring. Emergence of G. pyrenaicum and G. robertianum took place throughout much of the year after sowing. Seeds of all these species were relatively short-lived in cultivated soil, and few seedlings appeared after the second year. Seed survival was greater in G. dissectum. G. molle, Rumex acetosella. Ranunculus sceleratus and especially R. repens, of which emergence in the fifth year after sowing amounted to 4% of the seeds sown. Emergence from the persistent seed bank was mainly from May to September for G. dissectum and G. molle and during autumn for Ranunculus flammula and R. sceleratus, while seedlings of Ranunculus repens and Rumex acetosella appeared sporadically over most of the year.

Biogeochemical and geobotanical studies have been carried out in several areas of sulphide mineralization in northern Greece. In porphyry copper areas, mineralized zones can be delineated by mapping the distribution of Minuartia verna, or by measuring the copper content of Rumex acetosella and Thymus sibthorpii. Elevated levels of molybdenum in the soil are indicated by higher concentrations of this element in T. sibthorpii. In an area of barite mineralization, biogeochemical methods were not useful in showing the barium distribution, but did provide an indication of the associated lead mineralization. The appearance of the nickel accumulator Alyssum murale near a zone of antimonite mineralization seems to be related to sporadic occurrences of ultrabasic rocks nearby.

Study plots with ten types of disturbances were established in a Solidago-Aster community in western Pennsylvania. One year after disturbance, 93% of all species had vesicular-arbuscular mycorrhizae (VAM) and accounted for 92% of all plant cover. After 3 yr, 96% of the species had VAM and 96% canopy coverage. An adjacent 1 0-yr Solidago-Aster community had 100% VAM species. The VAM annuals, Ambrosia artemisEifolia and Setaria glauca, were major first year dominants while VAM perennials, Agropyron repens, Solidago canadensis, and Aster ericoides, dominated at 3 yr. The mean percent mycorrhizae of all dominants at 1 yr was 39% and 34% at 3 yr. Four disturbed sites had 100% VAM colonization after 1 yr and six sites after 3 yr. Severe physical disturbances (topsoil removed and topsoil-subsoil removed) resulted in complete colonization by VAM species and mean mycorrhizal infections of more than 75%. The plowed-disked-prometone and plowed-disked-vapam disturbances resulted in low levels of mycorrhizae after 3 yr. The plowed-disked-atrazine plot showed an initial severe decrease in percentage of mycorrhizae, but doubled its infection rate by 3 yr. Three non-mycorrhizal species (Chenopodium album, Rumex acetosella, and Polygonus persicaria) were observed during the 3-yr period. C. album was the major dominant after 1 yr in the plowed-disked-fertilized site and R. acetosella a dominant in the plowed-disked-prometone plot.

The sex ratios of natural populations of Rumex acetosella L. have been recorded during two growing seasons, along a successional gradient of abandoned agricultural fields of various ages (from 6 months to 15 years old), south of Paris. At the same time, male and female ramets have been collected to determine the resource allocation pattern of the different organs. We have observed that females of Rumex acetosella L. were more frequent than males at the younger stages, and that males predominated at the older ones. Concomitantly, there was a decrease in aboveground biomass and in the reproductive effort of the two sexes in the field, with increasing community maturity. The decrease in reproductive effort was confirmed, in controlled conditions, in the female genets only. Females always produced a higher reproductive effort and a higher aboveground biomass than males, which may explain why they were more abundant in the younger successional stages. Otherwise, our results show that sexual reproduction represented a high energetic cost which tended to consume root resources. Females, and mainly those of the younger stages which presented a high reproductive effort, may suffer more than males. The latter, which were more vigorous in vegetative reproduction and less affected by flower production than females, prevailed at older stages.

Ecological Investigation of a Meadow Developed on a Metal-Rich Soil The floristic structure of a meadow over a copper-rich soil was studied, and four different stages of vegetation succession were described. The following species dominate over the different stages: Minuartia verna, Thymus sibthorpii, Rumex acetosella and Chrysopogon gryllus. Soil analysis showed that the most undeveloped soil of the Minuartia stage exhibits the highest concentration of Cu and of twelve other elements, while the mature soil of the Chrysopogon stage exhibits the highest concentrations of Al, Ca, Na and Ni. An inverse relationship was found between the concentrations of Cu in the soil and the number of species in the forty sampling quadrats. Plant analysis showed that Minuartia verna and Rumex acetosella accumulate more copper in their tissues than the other two dominant species.

Seedlings from golden delicious apples (Malus domestica Borkh. 'Smoothee') were grown in the green- house with orchardgrass (Dactylis glomerata L. #3 DACGL), Kentucky bluegrass (Poa pratensis L. # POAPR), red sorrel (Rumex acetosella L. # RUMAA), and Korean lespedeza (Lespedeza stipulacea L. # LESSL) at four densities and four fertility levels. Orchardgrass and red sorrel inhibited tree growth more than Kentucky bluegrass on a per plant basis. Korean lespedeza inhibition of apple growth was associ- ated with the amount of root nodulation on the Korean lespedeza. Apple shoot dry weight over all fertility levels, ground cover species, and densities was predicted by a re- gression model based on increase with fertility and decrease with ground cover dry weight. These results indicate that the competitiveness between equal number of ground cover species is due to differences in biomass production. Addi- tion of nitrogen to the system increased nitrogen levels in apples but did not completely overcome apple growth in- hibition. Additional index words. Nutrients, Dactylis glomeratus, Poa pratensis, Rumex acetosella, Lespedeza stipulacea, POAPR, LESSL, DACGL, RUMAA.

Rumex acetosella, Trifolium repens, and Lolium sp. were grown in monoculture and mixture in a 3 × 3 arrangement of fertiliser and lime application to potted soil. Competition between the species described by the de Wit (1960) model of plant competition indicated that R. ace-tosella was least suppressed by either Lolium or T. repens on unlimed and infertile soil. Competition indices showed that the yields of mixtures of both R. acetosella and Lolium with T. repens on infertile soil were increased relative to the yields of the respective monocultures. and this effect was especially marked for the T. repens-R. acetosella mixture on unlimed infertile soil. The pH of soil derived from the experiment was higher after growth of R. acetosella than after growth of the other species. Also, residual yields of R. acetosella, Lolium, and T. repens grown in the soil after harvest of the first experiment indicated for R. acetosella and Lolium greater yields following T. repens. Also for the monocultures the res...

Summary Measurements were made of the yield and habit of two lowland populations and one mid-altitude population of R. acetosella grown in soil in tins at sites near sea level, 1,900 ft, and 4,200 ft in Canterbury. Soil from each site was transported between sites in an attempt to separate climatic and edaphic effects on yield and habit. Correlations between plant height and yield were calculated. Altitudinal change of climate was the major determinant of yield and habit. Soil responses indicated the tolerance of the species to acid, base-deficient soils. The greater yield of the two lowland populations relative to the mid-altitude population diminished markedly with increasing altitude. Evidence is presented of soil adaptation to the site of origin and of plant population adaptation to soil. It is concluded that the successful colonisation of tussock grasslands by R. acetosella can be partly related to its phenotypic plasticity associated with the natural selection of habits facilitating survival in this...

SUMMARY Cytological studies of the Rumex acetosella complex in the Netherlands have shown that in this country tetraploids and hexaploids occur. Such plants are referred by Love to R. tenuifolius and R. acetosella, respectively. Diploid angiocarpous specimens belonging to R. angiocarpus have not been encountered, in contradistinction to a report by Love. However, apart from gymnocarpous hexaploids, also angiocarpous hexaploids have been found to occur in the Netherlands. The range of distribution of these angiocarpous hexaploids corresponds with the distribution indicated by Love for angiocarpous diploids. The results of our studies render the occurrence of the diploid R. angiocarpus in the Netherlands most unlikely. Angiocarpy can not be considered a good diagnostic character to distinguish R. angiocarpus and, accordingly, the keys to the species of Rumex belonging to the complex and the circumscription of these species by Love and in several recent floral works are in need of revision.

Severe attacks by Ditylenchus destructor on potatoes in the south of Sweden appeared to have arisen from cultivation in infested soil. The principle risk of using slightly infected seed tubers, which in a field experiment gave a far less damaged crop than more severely injured ones, seems to be the possibility of spreading the nematode to new locations. For the occurrence of soil infestation, in some places very heavy, weed hosts were of major importance. Important weed hosts were Mentha arvensis, Stachys palustris, Potentilla anserina and Rumex acetosella, of which the last two have not before been reported as hosts. Underground decaying remains of potato plants infected by D. destructor may in autumn contain nematodes of some stage or stages which over-winter without the necessity for living plant tissue. Nevertheless, damage in potatoes seemed to become slighter after continuous cultivation of this crop.

Observations on the geographical distribution of plants frequently show an intimate connection between vegetation and soil. Some species of plants are to a certain extent indifferent to the chemical composition of the soil, while others are more or less strictly adapted to definite substrata. This led F. Unger, as early as I836, to divide all plants into three groups: (I) those indifferent to the chemical composition of the soil; (2) those showing a preference for certain soils; (3) those growing exclusively on certain soils. In a general way, the chemical composition of the soil determines a characteristic flora, a fact which was noticed long ago. Petry (i889) in Germany, Flahaut (I893) in France, Magnin (i893) in Switzerland, and others describe the distribution of plants on different soils. In this respect attention may be called to nitrophyte plants, which have been studied carefully by Sernander (i9i2). They grow on soils rich in NH4 and NO,, and usually occur in the vicinity of human dwellings. To the group in question belong some species of the families Chenopodiaceae, Cruciferae, Solanaceae, etc. As regards the relation between plants and lime soils, the opinions of scientists are divided. Some authors (Sendther, Nageli, Schimper and particularly the French school) ascribe paramount importance to the chemical composition of the soil, and give lists of plants absolutely avoiding lime soil: Calluna vulgaris, species of Erica, Pinus maritima, Pteridium aquilinum, Rumex acetosella, some Gramineae and Cyperaceae, Sphagnum, and many others. On the other hand, there exist species showing a marked preference for lime. Blytt (I893) established the fact that in Norway Ophrys muscifera and Libanotis montana grow exclusively on soils containing calcium. Adamovic (i909) gives lists of calcophilous plants for the Balkan, and Moss and Tansley do the same for England. For the Alps Kerner gives a list of the so-called parallel species belonging to the same genus, but growing respectively on schists and on limestone: Anemone sulphurea and A. alpina, Primula villosa and P. auricula, Ranunculus crenatus and R. alpestris, etc. Other scientists profess an entirely different theory, elaborated by Thurmann (i849), who was followed by Alph. de Candolle, Celakovsky, Krasan

Rumex hastatulus Baldw. is a dioecious annual plant native to the southeastern United States. Sex determination is controlled by a heteromorphic sex-chromosome mechanism and the species has the lowest chromosome number known in Rumex (Smith, 1955). In the North Carolina population, females are homogametic with eight chromosomes (2n = 6 + XX); males are heterogametic with nine chromosomes (2n = 6 + XY1Y2). The sex-chromosome mechanism resembles that of Eurasian R. acetosa, but sex determination in R. hastatulus depends upon the concerted action of the X-chromosomes, the Y-chromosomes, and the autosomes (Smith, 1963). This differs from the Drosophila-like X/A, Yneutral sex determination of R. acetosa (e.g., Yamamoto, 1938). The phylogenetic relationships and geographic history of R. hastatulus are uncertain. It is a member of the subgenus Acetosa, an Old World group with most of its forty or more species in Europe, the Near and Middle East, and Africa (Rechinger, 1949, 1954, 1958). Only three species of this subgenus are known from the Western Hemisphere, all from North America. These are the circumboreal R. acetosa L. (s. lat.) which extends southward into Montana and Wyoming (Beartooth Plateau); the Rocky Mountain and California Sierra species, R. paucifolius Nutt., which occurs as far south and east as north-central Colorado; and R. hastatulus Baldw. This latter species is allopatric with respect to all other members of the subgenus. Studies of sex determination in R. hastatulus (Smith, 1963) have been based almost exclusively upon material derived from the North Carolina population. Even in this geographically limited sample of the species, karyotypic variation occurs among the autosomes (Smith and Giles, 1959). A previously unknown karyotype, which differs from that of the North Carolina population both in chromosome number and in sex-chromosome organization, was discovered recently in material collected from Bastrop County, Texas. Rumex hastatulus: Growth habit, habitat, and geographic distribution.-The native American species, R. hastatulus is often confused with the adventive and ubiquitous "sheep sorrel," R. acetosella. Both species are dioecious and both are hastate-leaved "sorrels" with the sour taste which results from a high content of oxalic acid. In other respects the two species are very different. Rumex hastatulus is a cespitose, tap-rooted, winter annual which usually grows to 18-24 inches in the spring and produces the broadly winged fruits characteristic of the subgenus Acetosa. Rumex acetosella is a rhizomatous, matforming perennial which rarely reaches 18 inches in height. As the fruits do not have conspicuously winged valves, this species belongs to the subgenus Acetosella (Rechinger, 1937). Fields of R. hastatulus form bright red patches in the Coastal Plain landscape from North Carolina to northern Florida because of the intense anthocyanin coloration of the stems and young fruits. Closer examination reveals that the plants in these populations are heterogeneous, varying from greenish or straw-colored with little anthocyanin to others which are intense carmine or purplish rose. The Texas population, however, does not present the red aspect described above; here the plants 1 Contribution from the Department of Genetics, North Carolina Agricultural Experiment Station. Published with approval of the Director as Paper No. 1546 of the Journal Series. Supported in part by the National Science Foundation Program in Genetic Biology: Grant G2561 renewed as G5532 and G19401.

The variability of leaf form and panicle height of Rumex acetosella L. sensu lato was examined to separate genetic, developmental, and environmental components of variation. First seedling leaves were ovate and entire, subsequent leaves lanceolate to linear lanceolate, and uppermost cauline leaves linear and entire. The rate of transition of leaf form varied between populations and was accelerated by temperatures and photoperiods inducive to flowering. The allometric relationship between lamina length and width changed from about I for seedling leaves to less than 1 for cauline leaves. Seasonal changes of leaf form and environmental modifications of leaf form were related to changes in the proportion of vegetative and cauline leaves and allometric size effects on relative dimensions of mature leaves. Panicle height and leaf size were markedly modified by environmental factors and were of little value for taxonomic determinations of field samples. The greatest variability of leaf form occurred in ...

Summary Records of time of flowering obtained from herbarium specimens of Rumex acetosella L. indicated seasonal delays and a shorter period of flowering with increasing latitude and altitude, while earlier flowering was indicated in regions of Mediterranean climate. Observations on the time of flowering in a uniform environment of populations spanning 50° of latitude showed correlations with latitude, and deviations from this trend could be attributed to adaptation to montane, continental, or Mediterranean climates. Experiments showed that the species required long days for floral induction in the seedling year, the populations varying in the length of day required, with populations from high latitudes not flowering in the prevailing daylengths at Christchurch (43° 30′S). In the second year of growth all populations flowered in the prevailing daylength at Christchurch, although long days and high temperatures hastened the maturation of flowers and the populations varied in time of flowering. Population d...

Cytogenetic studies were made with particular emphasis on the sex-determining mechanism in Rumex acetosella (6 x = 42) and its hybrids (F 1, F 2, BC 1 and BC 2) with R. hastatulus (synthetic 4 x = 16 = 4 A +4 X = ♀ and 4 x = 18 = 4 A + 2 (X Y 1 Y 2) = ♂). Rumex acetosella was almost strictly dioecious with 50∶50 male and female. Breeding tests revealed that the males were heterogametic. The longest chromosomes (S), usually two, are the sex chromosomes of this hexaploid species. The S chromosomes are homomorphic in both male and female. The sex chromosome: autosome ratios, and the strong epistatic male effect of the S (M) chromosome in the polyploid dioecious species and in the hybrids, are evidence of an X/Y Melandrium type sex-determining mechanism controlled by a single pair of homomorphic sex chromosomes. Thus, the sex chromosome formula of the males was S (F) S (M) and that of females was S (F) S (F). The present approach is a new method for resolving the sex-determining mechanism in a dioecious species.

Summary Angiocarpic seeds occur in diploid, tetraploid and hexaploid populations of Rumex acetosella s.l.- gymnocarpic seeds occur in tetraploids and hexaploids only, and among the hexaploids in populations from northern and central Europe. Cell and organ sizes do not rigorously correspond with the various levels of ploidy, and the overlap in range and frequency results in monomodal distributions. All New Zealand populations are hexaploid and angiocarpic and are unlikely to have been introduced from northern and central Europe.

Single applications of 4.48 and 22.4 kg/ha of the ester formulation of (2,4,5-trichlorophenoxy)acetic acid (2,4,5- T ester), 2,4,5-T amine, and 2-(2,4,5-trichlorophenoxy)pro- pionic acid (silvex) to the ground cover and soil under apple (Malus sylvestris Mill.) trees significantly reduced the propor- tion of broadleaf plants to grasses. After six annual applica- tions of these herbicides, the ground cover consisted of almost pure stands of grasses. Six applications of 2-sec-butyl-4,6- dinitrophenol (dinoseb) + oil at 4.2 kg/ha + 374 L/ha and five times this rate decreased the proportion of broadleaf weeds to grasses, but one application did not change the proportion. One and six annual applications of dinoseb amine at 16.8 and 84 kg/ha significantly reduced the percentage of broadleaf weeds. One application of 3-amino-s-triazole (amitrole) at 4.48 kg/ha and six annual applications of amitrole at 22.4 kg/ha significantly decreased the percentage of broadleaf weeds. Six annual applications of 2,2-dichloropropionic acid (dalapon) + dinoseb amine at 47.6 + 84 kg/ha significantly increased the percentage of broadleaf weeds, especially mouseear chickweed (Cerastium vulgatum L.) and red sorrel (Rumex acetosella L.). Six annual applications of ammonium sulfamate (AMS) at 168 and 840 kg/ha increased the proportion of grasses to broadleaf weeds as did a single application at 168 kg/ha. AMS caused phytotoxic symptoms on young apple replants at the 168-kg/ha rate and also on mature trees at the 840-kg/ha rate. No phyto- toxic symptoms were noted with the other herbicides applied. diuron, and simazine. In Michigan, Putnam (5) has found that field bindweed, horsenettle (Solanum carolinense L.), Canada thistle (Cirsium arvense (L.) Scop.), common milk- weed (Asclepias syriaca L.), and poison ivy (Rhus radicans L.) have increased following herbicide use in orchards for 3 or more years. Witchgrass (Panicum capillare L.), fall panicum (P. dichotomiflorum Michx.), and yellow foxtail (Setaria lutescens (Weigel) Hubb.) often are found in plots treated with 2,6-dichlorobenzonitrile (dichlobenil) or sima

Rumex acetosella est une plante naturalisee tres repandue en Nouvelle Zelande, tant en terre arable que dans la vegetation indigene modifiee. Dans des vallees en cuvettes de l'Ile Sud, ayant une precipitation annuelle de 300 a 700 mm, des milliers d'hectares qui n'ont jamais ete laboures portent a present R. acetosella (2n=42) comme espece la plus importante, accompagnee de “mauvaises herbes” naturalisees et indigenes. Ce sont des regions ou les prairies naturelles a touffes de Festuca novaezelandiae ont ete ravagees au cours d'un siecle par des incendies successives et par la paissance de moutons et de lapins, animaux introduits par l'homme. Le groupement vegetal a Rumex — produit d'origine exotique (“exotic-induced”) — tel qu'il se trouve dans la partie nord de l'Ile Sud, est etudie et quelques releves en sont presentes. Une comparaison est dressee entre cette region et d'autres en Nouvelle Zelande, ainsi qu'avec les iles Tristan da Cunha dans l'Atlantique du sud et Masafuera dans le Pacifique du sud. Le Rumecetum, qui s'est propage la ou se trouvent en assez grand nombre ces animaux introduits, pourrait bien continuer a exister indefiniment, a moins que ceux-ci ne disparaissent.

It is found that if distilled water is allowed to flow through the leaves of terrestrial plants (Achillea millefolium, Chenopodium album, Rumex acetosella, Ficaria verna), the protoplasm of the cells exhibits increased fluidity. The terrestrial plants thus react in the same way as the earlier investigatedHelodea. The cause is not the absence of nutrient salts or of microelements, since nutrient solutions prepared from distilled water have the same effect. The cause is instead the absence of the fluidity-active substances that have earlier been demonstrated in the soil fluid, and which derive from plants.

SUMMARY Cytological studies have demonstrated the occurrence of tetraploids (2n = 28) and hexaploids (2n = 42) of the Rumex acetosella complex in Belgium. Diploids have not been encountered. In both the tetraploid and the hexaploid races angiocarpous plants have been recorded next to gymnocarpous ones. There is a correlation between the relative frequencies of the angiocarpous individuals and of the gymnocarpous ones in the hexaploid populations and the type of soil: on the loamy soils of Central and South Belgium almost exclusively angiocarpous plants occur in the populations, whereas in the populations on the sandy soils of the coastal area and of Belgian Brabant the gymnocarpous form predominates. Tetraploids are almost exclusively restricted to the populations found on the sandy soils of northern Belgium.

Particle concentrations derived from operation of a rotobar sampler at a midwestern location during 1965 to 1968 have confirmed the regular and substantial occurrence of Rumex pollen; field studies have implicated Rumex acetosella (sheep sorrel) as the primary source. Comparisons of rotobar and gravity slide data suggest that purely aerodynamic factors may decrease the recovery of Rumex pollen by the Durham sampler by as much as 50 per cent relative to grass pollen. A high frequency of positive skin reactivity to Rumex pollen extract was noted among 367 persons demonstrating some wheal and flare reactions on skin testing with extracts of common inhalant allergens. More than half of a group of positive skin reactors to Rumex extract also demonstrated positive nasal provocative tests with this material. Most, but not all, positive nasal reactors to Rumex had experienced pollinosis during the common period of Rumex and grass pollen prevalence, and at least some of these manifested negative responses on mucosal testing with grass pollen extracts. The combined aerobiological and clinical data suggest that specific sensitivity to Rumex pollen may contribute significantly to the severity of pollinosis in selected patients.

Studies on the population biology of dioecious plants have concentrated on deviations from the expected sex ratio of 1:1 (refs 1–4) and on sexual imorphism5–10. Sexual dimorphism may imply that the two sexes have different ecologies and this has been demonstrated for a number of animals11. Clearly, if males and females occupy at least partially different niches, competition between members of the two sexes will be reduced and observed sex ratios may be biased by the relative carrying capacities of the two niches. Putwain and Harper12 described differences in the seasonal patterns of growth of males and females in Rumex acetosa and Rumex acetosella and Freeman et al. 13 showed that the males of five dioecious plant species in northern Utah were more abundant on xeric microsites, while females were over-represented in the moister regions of each local environment. We report here that the growth of male and female plants of the annual Spinacia oleracea L. var. Viking is affected differently by population density, and this is reflected in the sex ratio.

Three tussock grassland sites were sampled along a climatic-soil gradient in the Mackenzie Basin, South Canterbury. There was a range within sites of 0.5 pH units in the 1-5 cm soil layer beneath different species. The pH was highest beneath composite flatweeds and Rumex acetosella and lowest below Festuca novae-zelandiae.

In this study about the weeds on arable lahd in Japan, the following five groups were suggested from their present geographical range, though it must be admitted that we cannot show their origin exactly. The historical consideration has also been given in this paper. 1) The recently naturalized plants have been introduced in recent year. 2) The old naturalized plants were introduced from Europe or Eurasia through China in the early stage of history. 3) Cosmopolitan. 4) The prehistoric naturalized plants were introduced from Central and South China in ancient times. 5) Native species. 1) The recently naturalized weeds on upland field : 27 species were originated from Europe, and some of the most important are as follows; Senecio vulgaris, Veronica arvensis, Cerastium visosum, Rumex Acetosella, Festuca Myuros, etc.; 5 from Eurasia, Veronica persica, etc.; 9 from Nouth America, Erigeron annuus, E. canadensis, Euphorbia supina, Oxalis Martiana, etc.; 6 from New Tropical regions or South America, Oenothera odorata, Amaranthus retroflexus, etc. 2) The old naturarized weeds: 8 species were originated from Europe. Sonchus brachyotis, Vicia sepium, V. tetrasperma, Stellaria neglecta. Polygonum nodosum, P. Persicaria, Poa annua and Polygonum lapathifolium. All these species are upland field weeds, except the latter one which is paddy field weeds. 25 species were originated from Eurasia, among them Galium spurium, Elsholtzia patrini, Lamium amplexicaule, Capsella Bursa-pastoris, Chenopodium album, etc., are in upland field, whereas the following 13 species are in paddy field, Elatine triandra, Cardamine flexuosa, Ranunculus sceleratus and the others. 3) The species of old world origin or Cosmopolitan; 27 species on upland are Stellaria aquatica, Bulbosylis barbata, Digitaris adscendens, Equisetum arvense, 0xalis corniculata, Portulaca oleracea, Amaranthus ascendens, Polygonum aviculare, etc.: 26 are found in paddy field, among them there are Bidens tripartita, MyrioPhyllum verticillatum, Nasturium palustre, Eleocharis acicularis, Hydrocharis asistica, Ceratophyllum demersum, Najas marina, etc. 4) The prehistoric naturalized species: They are originated from South eastern Asia and especially interesting because these weeds are attendant on rice plants. Among them, Eclipta alba, Dopatorium junceum, Lindernia angustifolia, L. Pyxidaria, Limnophila sesseliflora, Ludwigia prostriat, Rotala indica, Monochoria vaginalis, Eriocaulon sieboltianum, Cyperus diffomis, C. Iria, Fimbristylis miliacea, Echinochloa crus-galli var. oryzicola. etc. are most important. 5) The Japanese native species; there are endemic species and the mutual common species in Japan, Korea, China, or Siberia, etc. The former contains only two species; Pleioblastus spp. and Sagittaria Aginashi. The latter would be perhaps the native species in those days when Japanese archipelago was detached from the continent (the last part of Diluvial epoch or the early years of the Allucual epoch) The native species which can be seen in Eastern as well as Northeastern Asiatic continent are amounted about 130 species on upland field and about 90 on paddy field. The most species, however, are slightly harmuful weeds, i.e., they are grown on the bordering foot-path or in the edge of irrigation ditches. A few species are noxious. As mentioned above, most of the troublesome weeds in Japan were found among the foreign species

In 1930 the writer published in this journal an account of the vegetation of Heart's Content forest listing the plants then known to occur within the area. The stand is a remnant of the primeval forest which formerly covered much of northwestern Pennsylvania. A number of foresters and botanists, appreciating its ecological importance, have developed a lively interest in the area. Since 1928, when the initial studies were made, the place has been visited every summer and a number of additional species collected. The object of this paper is to record these species. The Scirpus sp. was immature but appeared to be S. cyperinus; it was impossible to collect flowers or fruit of either Ribes rotuzdifoliwni or Crataegus tenella, hence the identification of these species remains tentative. Some of the plants here reported seem to be recent invaders rather than natural components of the virgin forest. During the summer of 1929 cutting of immediately adjacent areas was completed, exposing the south and east sides of the virgin forest block. This exposure to sun and wind has certainly altered natural conditions within a considerable part of the forest and has made entry of a number of ruderals possible. A further factor in accounting for the recent arrivals seems to be the increasing use of the area by the public. Among the species which represent recent arrivals in the area are Dactylis glomerata, Agrostis alba, Populis tremiloides, P. gr iididentata, Rumex acetosella, Polygomurn acre, Phytolacca decaundra, Lysimacliia qunadrifolia, SolanxUn dulcamtara, Bidens discoidea, Erechtites hieracifolia, and Hieracium aurantiaci1n. Plants occurring only in the grazed portion of the forest are not included. Information on such species may be obtained from an earlier paper by the writer.

Four plant species of woodland clearings - Avenella flexuosa, Chamaenerion angustifolium, Rumex acetosella, and Senecio sylvaticus - were grown on five different horizons of an iron-humus podzol profile. Reasonable growth was achieved only on the A0 horizon, which was rich in organic matter. The growth reduction on the other horizons was correlated with low concentrations of manganese and phosphorus in soils and plant organs. The restriction of so-called acidophilous species to acid soils is interpreted as meaning that they have a need for a high supply of manganese.

The uptake of copper, lead and zinc by plants in several areas of sulphide mineralisation in eastern Thrace, Greece, has been studied. Two indicator plants for sulphide deposits in central Macedonia,Rumex acetosella L. andMinuartia verna (L.) Hiern, have not been found on Thracian soils high in sulphides. However, the widespread speciesHypericum perforatum L. andScleranthus perennis L. are tolerant of the elevated metal levels in these soils. AlthoughH. perforatum is not useful as a biogeochemical indicator, the levels of Cu, Pb and Zn inS. perennis were found to be strongly correlated with the corresponding concentrations in the soil.

As a zone of transition between North Africa and the European continental regions, the Western Mediterranean area has an original flora, rich in species with a localized distribution (‘Mediterranean species’ sensu stricto), but also with many steppic species coming from semi-arid countries (Maghreb) and septentrional species, well settled in the wettest biotops.

Male and female plants of Rumex acetosella were grown on a moisture gradient to measure possible differences in the drought tolerance of the sexes. The growth of both sexes declined under water stress but males were significantly more drought tolerant. This could not be explained by greater water use efficiency in the male plants; measured rates of both photosynthesis and leaf conductance did not differ significantly between the sexes. Multiple discriminant analysis showed that the sexes differed at all moisture regimes in their overall patterns of biomass allocation. Males had proportionately greater investment in root and leaf tissue which could explain their growth advantage over females under water stress. Despite essentially equal water use efficiencies, on a per plant basis males, with more leaf and root biomass, could fix more carbon and more rapidly exploit the local water resource than females. Thus the pattern of biomass allocation rather than intrinsic physiological differences appears to explain the greater drought tolerance of male plants of Rumex acetosella.

Rumex acetosella, spec. nov. 22. Rumex floribus dioicis, foliis lanceolato-hastatis. Vir. cliff. 32. Hort. cliff. 139. Fl. lapp. 131. Fl. suec. 296. Roy. lugdb. 231. Gron. virg. 153. Acetosa arvensis lanceolata. Bauh. pin. 114. Oxalis ovina. Tabern. ic. 440. ��. Acetosa lanceolata angustifolia repens. Bauh. pin. 114. prodr. 55. ��. Acetosa arvensis minima non lanceolata. Bauh. pin. 114. ��. Acetosa minor erecta, lobis multifidis. Bocc. mus. 164. t. 126. Habitat in Europae pascuis & arvis arenosis. ���, Published as part of Linnaeus, Carolus, 1753, Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas, Stockholm :Laurentius Salvius on page 338, DOI: 10.5281/zenodo.3931989

Patterns of resource allocation in the dioecious Rumex acetosa and R. acetosella were investigated. Males were found to allocate more to reproduction during flower production than females, whereas females invested considerably more in reproduction during seed production. Altogether, females allocated both a higher total amount and a higher proportion of energy to reproduction than did males. By regression analysis, the influence of plant size on reproductive effort was examined separately for males and females. The results indicated that while reproductive effort is sometimes lower for tall plants than for small plants, size-independent effects have a greater influence on reproductive effort than size distribution. An analysis of variance was conducted to investigate the effects of population, season, sex and their interactions on plant size, and an analysis of covariance was used to study differences in resource allocation patterns. Different interaction effects were found to be most important in the two species of Rumex.

While the author (Gaertner 1962) has previously reported on the freezing, preservation and preparation of native wild plants of Ontario for culinary purposes, this communication concerns itself primarily with three common weeds: sow thistle (Sonchus spp.), evening primrose (Oenothera biennis L.) and sheep sorrel (Rumex acetosella L.), which might add to our winter diet. Two of the three plants are European introductions, usually considered extremely troublesome when present in the field; the third is a native biennial. In addition, the use of the unopened male cones of pine (Pinus spp.) and spruce (Picea spp.) are described.

(1) Seeds of fourteen species were placed in the mor layer of a north Swedish coniferous forest in autumn 1979. Samples were excavated and tested for viability at intervals until autumn 1984. (2) Three species showed no innate dormancy and germinated to a large extent in the soil: Epilobium angustifolium and Pinus sylvestris were eliminated within one year, but a small fraction of the sample of Deschampsiaflexuosa remained viable for five years. (3) Three others had a strong innate dormancy which was gradually lifted within a few years, resulting in a high degree of germination in the soil: Prunus padus was eliminated within three years but a fraction of Sorbus aucuparia and Trientalis europaea remained viable after five years. (4) For nine species no germination in situ was evident, but viability was generally well maintained over five years. For three of these (Calluna vulgaris, Rubus idaeus and Rumex acetosella) germination was 80-100% after 5 years. (5) For Rubus idaeus and Rumex acetosella there was an increase with storage time in the soil in the proportion of seeds germinating in the laboratory during the first few days after excavation, indicating gradual changes in dormancy characteristics over several years. (6) A proportion of the seeds of Betula pendula, Sorbus aucuparia, Vaccinium myrtillus and V. vitis-idaea had their seed coats partly degraded after five years in the soil, although this had not affected the viability of the seeds. (7) The patterns of depletion observed in the seed populations did not indicate a constant rate of depletion, suggesting that the long-term survival of seeds in boreal forest soils may be very different from that found in many agricultural soils.

The effects of five residual herbicides and two mixtures of herbicides on tree and weed growth were studied in two trials over two consecutive seasons in a young peach orchard at Bathurst, New South Wales. In the first trial, dichlobenil at 4.5 and 9.0 kg ha-1 increased tree growth and suppressed weeds, but the residual effects of the low rate were short; simazine (2.2 kg ha-1), trifluralin (2.2 kg ha-1) and simazine (1 1 kg ha-1) plus trifluralin (1.1 kg ha-1) also reduced weed incidence but did not improve tree growth. In the second trial, terbacil (2.2 kg ha-1) and mixtures of diuron (1.1 kg ha-1) and terbacil at 1.1 or 2.2 kg ha-1 effectively controlled weeds, giving faster tree growth. Terbacil (1.1 kg ha-1) and diuron (1.1 kg ha-1) suppressed broadleaf but not grass weeds. Terbacil (1.1 kg ha-1) improved tree growth only in the second season; diuron (1.1 kg ha-1) did not affect tree growth. None of the peach trees displayed toxic symptoms. The main weeds present in the trial site were: Amaranthus powellii, Chenopodium album, Polygonum aviculare, Lepidium hyssopifolum, Lactuca serriola, Rumex acetosella, Sonchus oleraceus, Plantago lanceolata, Cynodon dactylon, Bromus sp, and Eragrostis sp.

Environmental requirements for seed germination and seedling growth vary appreciably among pasture species. Therefore, it is possible that the botanical composition of pastures may be manipulated by timely seasonal exposure of the soil-seed reserve to conditions that promote germination differentially. This possibility was examined in two Mediterranean type pastures in which plots were tilled once per year, each in a different month, for 2 years. For several pasture species, effects were estimated with respect to numbers of soil seeds, numbers of emergent seedlings and canopy coverage. Individual species showed specific behaviour patterns. Seeds of sorrel (Rumex acetosella) and wireweed (Polygonum aviculare) maintained abundant seed in the soil, those of annual ryegrass (Lolium rigidum) and subterranean clover (Trifolium subterraneum) were less persistent, and seeds of red brome (Bromus rubens) and silvergrass ( Vulpia spp.) occurred only seasonally in the soil-seed pools. Mature plants of red brome, silvergrass and subterranean clover attained dominance only in summer and early autumn-tilled plots. Annual ryegrass was more abundant when soil was cultivated in late autumn and early winter, whereas sorrel and wireweed were significant only in plots ploughed in winter. Thus botanical composition may be altered radically by time of tillage, and this has several practical implications for pasture management and weed control.

An experiment was conducted to determine if leaves of Rumex acetosella changed size or shape when under drought stress, and if leaves of plants taken from a xeric environment responded differently to drought stress than leaves of plants from a mesic environment. Mean leaf areas were significantly larger in plants from xeric populations in both dry and control treatments. The five largest leaves of each control individual were significantly larger on xeric plants and on those plants whose clone had survived the low moisture stress. Multivariate analyses indicated no leaf shape differences between moisture treatments or between habitat of origin. The results suggest a physiological rather than a morphological basis for drought tolerance in R. acetosella.

Exclosures established in 1979 at 3 grassland sites in the Tidbinbilla Nature Reserve kept out kangaroos and rabbits, kangaroos only or rabbits only, at each site. The occurrence of some plant species changed over time in all treatments as a result of natural plant succession, but other changes were caused mainly by grazing by the grey kangaroo [Macropus giganteus]. The 3 sites were different floristically mainly in the percentage cover of Themeda australis, Bromus molliformis, Hypochoeris radicata and Trifolium spp. The frequency of occurrence of moss, Haloragis tetragyna, Rumex acetosella, B. molliformis and Trifolium spp. also differed between sites. Compared with ungrazed plots, exclosures grazed by kangaroos had decreased percentage cover of Glycine clandestina, Aira caryophyllea and Haloragis tetragyna whereas moss species increased. Bothriochloa macra, which occurred only at 1 site, increased on plots grazed by kangaroos and produced a significant site-treatment interaction. The plots grazed by kangaroos had increased frequency of occurrence of dicotyledonous seedlings, A. caryophyllea, Danthonia sp. and H. radicata. Since 1982-83, the frequency of occurrence of G. clandestina, Lomandra filiformis and Verbascum thapsus decreased where the grey kangaroo grazed. New species recorded in 1986, that appeared only in sites grazed by the grey kangaroo, included B. molliformis, Eriochilus cucullatus, Trifolium campestre, Luzula sp. and Silene gallica. Species such as Hibbertia obtusifolia, Plantago lanceolata, Lactuca serriola, Conyza bonariensis, Danthonia sp. and Hydrocotyle laxiflora were not present on plots grazed by the grey kangaroo. Height of Acrotriche serrulata, dicotyledonous seedlings, G. clandestina, H. laxiflora, Hypericum gramineum, H. radicata, L. filiformis, Poa sp., Sorghum leiocladum and T. australis was reduced markedly in plots grazed by the grey kangaroo, although grazing did not always appear to be the reason. The reduction in the height of the vegetation made the areas unsuitable for stubble quail (Coturnix pectoralis) and Richard's pipit (Anthus novaeseelandiae), and also affected certain invertebrates.

(1) Nitrogen fixation rates associated with various plant species growing on china clay waste materials were estimated using the acetylene reduction technique. (2) Rates associated with leguminous species (Lupinus arboreus, Ulex europaeus, Trifolium repens) were at least ten times greater than those of non-leguminous species. (3) Of the swards comprising non-leguminous species, only those with Rumex acetosella or Festuca rubra and Agrostis tennis fixed significant amounts of nitrogen, presumably in their rhizospheres. Low rates were detected in some other species. The estimated rate of atmospheric input of combined nitrogen was greater than the input from any of the non-leguminous species. (4) There was no detectable fixation by free-living micro-organisms, except with an added carbon source. (5) All rates were low, probably because of an exceptionally dry summer. (6) Legumes are therefore recommended as the most valuable method of promoting nitrogen accumulation. Nevertheless up to 50 Kg N ha-' could be applied as fertilizer to Trifolium repens without affecting its fixation rate.

Contributors. Foreword. Preface. Profile of John L. Harper. Scientific Publications of John L. Harper Dynamics and Evolution of Plant Populations in Natural or Seminatural Environments: Past, Present and Future: Studies on the Population Dynamics of Some Long-lived Trees, J. Ogden. Plant Demography: A Community-level Interpretation, J. Sarukhan, D. Pinero and M. Martinez-Ramos. Fires and Emus: The Population Ecology of Some Woody Plants in Arid Australia, J.C. Nobel. Differences in Life Histories between Two Ecotypes of Plantago lanceolata L., J.M. van Groenendael. Variation and Differentiation in Population of Trifolium repens in Permanent Pastures, . Disasters and Catastrophies in Populations of Halimione portulacoides, Ad H.L. Huiskes and A.W. Stienstra. Establishment and Peri-establishment Mortality, R.E.L. Naylor. Population Biology and the Conservation of Rare Species, H.J. Harvey. Biology of Invasive and Weedy Species: Invading Plants: Their Potential Contribution to Population Biology, R.N. Mack. Proso Millet (Panicum miliaceum L.): A Crop and a Weed, P.B. Cavers and M.A. Bough. Population Dynamics of a Few Exotic Weeds in North-east India, R.S. Tripathi. Weeds and Agriculture: A Question of Balance, B.R. Trenbath. The Demographic Interpretation of Plant Form: Application to Plant Competition and Production: On the Astogeny of Six-cornered Clones: An Aspect of Modular Construction, A.D. Bell. The Importance of Plant form as a Determining Factor in Competition and Habitat Exploitation, P.H. Lovell and P.J. Lovell. Modular Demography and Form in Silver Birch, M. Jones. Modular Demography and Growth Patterns of Two Annual Weeds (Chenopodium album L. and Spergula arvenis L.) in Relation to Flowering, L. Maillette. A Modular Approach to Tree Production, M. Franco. Plant Interference: The Effects of Neighbours: Plant Responses to Crowding, A.R. Watkinson. The Thinning Rule and Its Application to Mixtures of Plant Populations, J. White. The Influence of Pathogens and Predators on Plant Populations: Pathogens and the Genetic Structure of Plant Populations, J.J. Burdon. Sex Ratios, Clonal Growth and Herbivory in Rumex acetosella, J.L. Doust and L.L. Doust. The Role of Grazing Animal, R. Dirzo. Plant Reproductive Biology: Islands and Dioecism: Insights from the Reproductive Ecology of Pandanus tectorius in Polynesia, P.A. Cox. The Meaning and Measurement of Reproductive Effort in Plants, F.A. Bazzaz and E.G. Reekie. Index.

THE species Rumex acetosella L. is a weed, which seems to be distributed all over the northern hemisphere. It has been investigated cytologieally by Roth1, who counted the chromosome number n = 16 (2n = 32), and later, among others, by Meurman2, Kihara3, and Jensen4, who all found the number to be hexaploid or 2n = 42.