Polytrichum Juniperinum Hedw Research Articles

Moss regeneration for lithium mine waste rock revegetation in Québec, Canada

Despite bryophytes being well adapted to various ecological settings, they are rarely considered in reclamation projects. In this study, propagation regenerative capabilities of bryophytes on different substrates (sand, amphibolite, and pegmatite) and conditions (with or without peat amendment, shade and shredding) were tested in greenhouse and field experiments. In the greenhouse trial, after 6 months of reintroduction, Racomitrium species ( Racomitrium canescens (Hedw.) Brid. and Racomitrium elongatum Frisvoll.) had higher regeneration compared to Polytrichum species ( Polytrichum juniperinum Hedw. mixed with Polytrichum piliferum Hedw.; a combination of shade (65% shading) and peat amendment (0.5 cm depth) was found to be particularly effective, resulting in up to 100% of Racomitrium species regeneration; shredding the stems of Polytrichum species into small pieces of 0.5–1.0 cm inhibited its regeneration. In the field trial, peat amendment had no effect on moss regeneration. The addition of fluvioglacial sand or till on waste rocks promoted bryophytes regeneration in both the greenhouse and field. These results provide science-based practical knowledge to support the inclusion of native bryophytes in waste rock restoration plans for mines located in northern boreal forests.

Мхи лесов юго-западного побережья Байкала (Иркутская область) и их экологическое распределение

Forest moss flora of the southwestern coast of Lake Baikal is diverse both from a floristic and ecological point of view. 211 moss species are identified in the territory, of which 5 are listed in the Red Book of the Irkutsk Region [2020]. The forest types of the study area with their moss species diversity, as well as the ecotopes occupied by bryophytes are considered in detail. Light-coniferous forests are widespread in the study area with a total of 100 moss species found. These are mainly representatives of the families: Bryaceae (9 species), Dicranaceae (8), etc. Dark-coniferous forests, which spread along the river valleys (especially in the head reaches), participate in the formation of the upper forest border. There are 74 moss species in these forests, of which representatives of the families Dicranaceae (8), Sphagnaceae (6), Mniaceae (6), etc. prevail. Mixed forests are widely represented. Most of these are secondary forests. 121 leafy moss species grow in the mixed forests. These are mainly representatives of the families: Dicranaceae (15), Mniaceae (11), and Brachytheciaceae (10). In total, 132 moss species grow on the forest soil. The soil cover dominants in all the forest types are quite common mass species: Abietnella abietina (Hedw.) M. Fleisch., Hylocomium splendens (Hedw.) Bruch et al., Polytrichum juniperinum Hedw. and Sanionia uncinata (Hedw.) Loeske are less often found. All of them are the boreal flora representatives. In places with sufficient moisture, the projective moss cover can reach 70–95%. 38 moss species are found on the exposed ground. 56 epixil and 42 epiphytic moss species are found. Epilithic species make up a significant part of the forest moss flora (142 species). It is explained by the presence of a large number of rocky substrates. The distribution of epilithic species is greatly influenced by air humidity, illumination, and the presence of fine-earth humus material

Heavy metal content in moss samples from Jebel Marra, Darfur, Sudan

A survey of heavy metal contents in 9 moss species: Barbula ehrenbergii (Lor.) Fleisch, Pleurochaete squarossa (Brid.) Lindb., Tortella humilis (Hedw.) Jenn, Pholonotis longiseta (MMichx) E. Britton, Philonotis tenuis (Hedw.) Brid, Funaria hygrometrica Hedw, Bryum pseudotriquetrum (Brid.) Shwaegr, Thuidium furfurosum (Broth.) Broth and Polytrichum juniperinum Hedw. Collected from three sites in Jabel Marra region, Darfur, Sudan was carried out . Concentrations of the elements sodium, potassium, zinc, calcium, copper, manganese and iron in the mosses gave an indication of the soil content in the selected sites and significant differences in heavy metal concentrations were recorded for different sites.

СТРУКТУРНО-ФУНКЦІОНАЛЬНА ОРГАНІЗАЦІЯ МОХОВИХ ДЕРНИН НА ТЕХНОГЕННО ЗМІНЕНИХ ТЕРИТОРІЯХ ЧЕРВОНОГРАДСЬКОГО ГІРНИЧОПРОМИСЛОВОГО РАЙОНУ

Structural and functional features of the bryophytes of different life forms, depending on the humidification of locality conditions of their growth in technogenically transformed territories of the Chervonohrad mining and industrial area, are established. Significant differences in water absorption and its retention by orthotropic assimilative and orthotropic brown parts of the shoots with rhizoid tomenta in Campylopus introflexus (Нedw.) Вrid. (low dense turf) and Polytrichum piliferum Hedw. (low smooth turf) as well as plagiotropic heterotrophic rhizomes in Polytrichum juniperinum Hedw. (high smooth turf) were revealed. In contrast to Campylopus introflexus turf, in which the length and dry matter mass are almost the same in assimilating and brown parts of the shoots, in the Polytrichum piliferum , the green part constitute 20–30 % of the shoots length and 74.0–77.6 % of their total dry mass. It was established that in the ectohydric moss Campylopus introflexus brown part of the shoots with rhizoid tomenta was losing water more slowly than assimilative one regardless of the water regime of the moss’ locality, which caused external conduction along the entire surface of densely foliaceous shoots. In endohydric moss clumps of P olytrich um genus the water balance was provided mainly by apical absorption and water retention by the assimilative part of the shoots; and brown non-foliaceous part of the stem and underground rhizomes mainly prevent the loss of endohydric water and carry out only capillary function – the maintenance of external water between the rhizoids of the shoots of individual moss plants. The apical and basal gradient of carbohydrates assimilation in the Campylopus introflexus shoots contributed to the resistance to water deficiency and the formation of apical reproductive organs, while in the high moss turf of the genus Polytrichum Hedw. more efficient starch storage and the ability to vegetative reproduction became apparent in brown and plagiotropic parts of the shoots.

Characterization and Phylogenetic Analysis of Chloroplast and Mitochondria Genomes from the Antarctic Polytrichaceae Species Polytrichum juniperinum and Polytrichum strictum

In this study, the organelle genomes of Polytrichum juniperinum Hedw. and Polytrichum strictum Menzies ex Brid. (Polytrichaceae, Bryophyta) from Antarctica were sequenced and compared with the plastomes of the model moss species Physcomitrella patens Brid. The sizes of the cpDNA in P. juniperinum and P. strictum were estimated to be 55,168 and 20,183 bp, respectively; the sizes of the mtDNA were 88,021 and 58,896 bp, respectively. The genomes are very similar to each other, with the possible loss of petN in the cpDNA, which also showed some gene inversions when compared with the cpDNAs of P. patens Brid. In the mtDNA, it is possible that rps10 was lost. In contrast, Antarctic Polytrichaceae species have nad7 and orf187, without the occurrence of rearrangement events. Phylogenomic analyses of the plastid and mitochondria revealed that the majority-rule tree suggests some differences in the plastids ancestry, however, P. juniperinum and P. strictum were grouped in the same clade in chloroplast, but in mitochondria P. strictum was grouped with Atrichum angustatum (Brid.) Bruch & Schimp. This study helped us understand the evolution of plastomes and chondriosomes in the family Polytrichaceae, and suggest a hybridization event with relation to the mitochondrial data.

Productivity of Polytrichum juniperinum Hedw. in forest ecosystem of Tatarstan

The values of linear and phytomass increments for the period May - October 2016 in forests of Tatarstan (central part of European Russia) are studied. The average values of increments for Polytrichum juniperinum Hedw. are provided. The relation between habitat characteristics and the productivity of Polytrichum juniperinum is discussed.

The influence of contrasting ground cover vegetation on soil properties in the NJ pine barrens

Upland forests of the New Jersey pine barrens are characterized by a pine and oak forest canopy. The herbaceous layer consists primarily of ericaceous shrub species. Scattered throughout the region grass-sedge and lichen–moss dominated patches under a pine canopy can also be found. It is generally believed these patches come about after severe disturbance. These patches can persist even in the absence of further disturbance. In this study, examples of three herb layer community types: ericaceous (predominantly Gaylussacia baccata Wang.), graminoid (almost exclusively Carex pensylvanica Lam.) and lichen–moss dominated communities (Cladonia spp. and Polytrichum juniperinum Hedw.), in close proximity to one another, from three different forest locations were examined. We determined whether graminoid and lichen dominated communities differ significantly in edaphic factors from the surrounding forest herbaceous layer vegetation matrix (ericaceous dominated community). In order to characterize the sites canopy and herbaceous layer vegetation and surface cover were assed. Soil particle size, soil carbon, respiration, microbial biomass and extractable nitrogen were also determined. Our analysis found only minor differences in forest canopy vegetation and no difference in soil particle size among forests or among communities. The results further suggest that differences in soil chemical parameters are the result of differences in the vegetation rooting architecture and decomposability. The lichen–moss dominated communities are distinguished by more bare ground, low bulk density, low nitrogen availability and a preponderance of microbial biomass in the upper 5cm of the soil profile. The high soil bulk density in lichen communities is presumably a function of its smaller root biomass content, greater percent bare ground cover and lower litter inputs. The ericaceous dominated communities are distinguished by greater presence of tree seedlings, low bulk density, lower nitrogen availability a large above ground biomass (AGB) and below ground biomass (BGB). Despite a significantly greater overall AGB the ericaceous community leaf mass is no larger than the graminoid community leaf mass or lichen–moss dominated community AGB. The graminoid dominated communities were distinguished by higher levels of extractable ammonium, soil organic matter (SOM) as represented by loss on ignition (LOI). Although the communities did not vary significantly in soil particle size the Pearson correlation analysis indicates that the significantly greater levels of soil carbon, ammonium and nitrate characteristic of the graminoid community are positively correlated with % silt–clay and negatively correlated with sand. Our results suggest that the subtle physical and chemical property differences between each of the communities may be due to a biogenic origin. This may explain, at least in part, the persistence of differing herb layer community type dominance.

Seasonal acclimation of the moss Polytrichum juniperinum Hedw. to natural and enhanced ultraviolet radiation

Short- and long-term changes in the methanol-extractable UV-absorbing compounds and biomass of the pioneer moss Polytrichum juniperinum in response to natural and enhanced UV radiation were studied. Under natural conditions, the compounds were found to fluctuate seasonally. In summer these compounds correlated negatively with irradiation. The concentration was low in July after a period of simultaneous heat, drought and high irradiation. Transient positive correlation between daily concentration and UV was seen in June. The concentration increased towards autumn and was relatively high under snow. Two enhanced UV experiments were performed. Seasonality in the compounds was again observed, with negative correlations with irradiation. During the first weeks, a transient inhibition of compound production was observed after the daily UV-B treatment. After six years of modulated UV-treatment in situ, photosynthesising biomass decreased under UV-B and increased under UV-A. A larger variation in the UV-absorbing compounds was observed under UV-B treatment.

Protective effects of three extracts from Antarctic plants against ultraviolet radiation in several biological models

The photoprotective effect of the methanolic extracts of three Antarctic plant species – Deschampsia antarctica Desv., Colobanthus quitensis (Kunth) Bartl., and Polytrichum juniperinum Hedw. against UV-induced DNA damage was investigated in hamster lung fibroblasts (V79 cells) and in a biomonitor organism Helix aspersas, using comet assay. The protective, mutagenic, and antimutagenic profiles of these extracts were also evaluated using haploid strains of the simple eukaryote Saccharomyces cerevisiae, and antioxidant activity were investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, as well as the hypoxanthine/xanthine oxidase assay. At the concentration range employed, the extracts were not cytotoxic or mutagenic to S. cerevisiae. In addition, the treatment with these extracts enhanced survival, and decreased induced reverse, frameshift, and forward mutations in a dose-response manner in all UVC doses employed. The plants extracts did not generate DNA strand breaks in V79 cells, and the treatment significantly decreased DNA damage induced by UVC. Extracts significantly decreased UVC-induced lipid peroxidation in V79 cells , showing a clear antioxidant property. Moreover, results of comet assay in V79 cells, employing Fpg, Endo III, and Endo V enzymes, demonstrated significant reduction of UVC-induced DNA damage after pre-incubation with these extracts. The treatment with all tested extracts were much less efficient against UVC-induced cytotoxicity in the yeast strain defective in photolyase as compared to the wild type strain, suggesting that this DNA repair pathway is stimulated by substances present in the extracts. All extracts showed a significant inhibitory effect in the hypoxanthine/xanthine oxidase assay, and they had the ability to scavenge DPPH. In H. aspersas, the treatment was able to protect against UVC-induced damage. In conclusion, D. antarctica, C. quitensis, and P. juniperinum extracts present photoprotective properties, which can be attributed to molecules, such as flavonoids and carotenoids, which act as UV-absorbing molecules and as antioxidants, as well as stimulate DNA-repair processes.

Dynamics of ground vegetation after surface fires in hemiboreal Pinus sylvestris forests

The aim of this work was to investigate the changes of ground vegetation (field layer: mosses, lichens; ground layer: herbs, shrubs, tree seedlings and saplings) and regeneration of tree species in pine forests after surface fires. The study area was located in Southern part of Lithuania in hemiboreal zone of Europe. The field and ground vegetation was recorded in forest stands burned in 1992 and 1994–2002 and compared with the nearby control fire untouched areas. We selected five burned areas for each year (total 50 burned stands). Vegetation sampling was conducted during July and August 2003. For vegetation description in each stand we systematically placed twenty 1 m × 1 m plots. Mann–Whitney nonparametric test was used to identify significant differences in vegetation between burned and untouched areas. It was determined that species richness increased after fire. Early successional species such as Agrostis capillaris L., Calamagrostis epigejos (L.) Roth, Chamerion angustifolium (L.) Holub, Festuca ovina L. and Melampyrum pratense L. invaded in burned areas immediately after fire. Abundance of dominant species ( Vaccinium myrtillus L. and Vaccinium vitis-idaea L.) recovered after 5 years. Pioneer moss species ( Polytrichum piliferum Hedw. and Polytrichum juniperinum Hedw.) replaced late successional mosses ( Dicranum polysetum Sw., Dicranum scoparium Hedw., Hylocomium splendens (Hedw.) Schimp. and Pleurozium schreberi (Brit.) Mitt.). Species number in the shrub layer decreased. Juniperus communis L. was killed by fire. Amount of undergrowth decreased first 4 years after fire. Saplings of Picea abies (L.) Karst., disappeared at all. Fire stimulated regeneration of Pinus sylvestris L., especially first 4 years after fire. Herbaceous and dwarf shrubs recovered 5–6 years after fire, moss cover—9 years after fire. Differences in moss species composition still remained 11 years after fire. Main finding suggest that fire is favourable to biodiversity of pine forest ecosystems. Fires induce regeneration of pine trees and can be used for restoration of pine forest.

Contrasting terrestrial lichen, liverwort, and moss diversity between old-growth and young second-growth forest on two soil textures in central British Columbia

The diversity and abundance of terrestrial lichens, mosses, and liverworts were examined and compared between two ages of forest (old-growth and young second-growth) on two dominant soil types (fine- and coarse-textured soils) in subboreal spruce forests in central British Columbia. Major differences in species composition were found between forest ages, with 30% of species found only in old-growth forest and 21% found only in young second-growth forest. Liverworts were much more common in old-growth sites with half the liverwort species found exclusively in old-growth, and 90% of the recorded liverwort observations occurring there. Different moss species assemblages dominated old-growth and second-growth sites, with much of the terrestrial cover of second-growth sites composed of Polytrichum juniperinum Hedw. Young second-growth forest had higher cover of lichen species than old-growth forest. Lichens and bryophytes used different terrestrial substrates in each forest age, with higher cover of mosses and lichens occurring on woody substrates in old-growth, irrespective of substrate availability. Nonmetric multidimensional scaling ordination clearly separated plots by forest age and also showed soil texture to be a defining variable. Though not statistically significant, there was increased bryophyte diversity on coarse-textured soils and increased lichen cover on fine-textured soils.

Polarity and endoplasmic microtubules in food‐conducting cells of mosses: an experimental study

SUMMARYThe effects of decapitation and of drugs affecting microtubules, microfilaments and the endomembrane system, on the ultrastructure of food‐conducting cells have been studied in the sporophyte of the mosses Polytrichum juniperinum Hedw. and Mnium hornum Hedw. In both species decapitation caused a marked reduction of cellular polarity. Moreover in Mnium but not in Polytrichum decapitation induced the disappearance of endoplasmic microtubules (MTs), the loss of longitudinal alignment of organdies and the accumulation of abundant starch. Starch accumulated in the cortical parenchyma cells in Polytrichum. In both species extensive MT depolymerization was induced by 100 μM oryzalin, whereas 10 μM oryzalin was less effective and 2·5 mM colchicine had no apparent effect. Treatment with 100 μM oryzalin also caused disruption of organdie alignment, alterations in the shape and position of the nucleus and a marked reduction in, or disappearance of, endoplasmic reticulum, trans Golgi network and membrane‐bounded tubules, that were abundant in the controls. Treatment with 10 μM monensin partially mimicked the effects of oryzalin, causing a reduction of the endomembrane system and disappearance of most endoplasmic MTs. Neither oryzalin nor monensin suppressed cellular polarity. Cells treated with D2O or the actin microfilament inhibitor cytochalasin D showed no structural alterations. The data indicate that: (a) endoplasmic MTs have a major role in organelle alignment and shaping in food‐conducting cells of mosses; (b) cellular polarity depends on the presence of a source/sink gradient and is not directly associated with MTs; (c) interactions between MTS and organelles, notably the ER and other components of the endomembrane system, have mutually stabilizing effects.

Microgeographic genetic variation in the haploid and diploid stages of the moss Polytrichum juniperinum Hedw.

Electrophoretic variability at six enzyme loci was used to examine genotypic variation in the haploid (gametophyte) and diploid (sporophyte) stages of the moss Polytrichum juniperinum Hedw. from a population in eastern Newfoundland. Samples from 16 sites revealed 13 six-locus haploid genotypes and a total of 18 gametophyte genotypes (ten male and eight female) when the genotypic data were combined with sex. Gametophyte genotypic diversity was low within each site and there was marked microgeographic differentiation between sites within the population. There was, however, no relationship between genetic and microgeographic distances among the sites. The observed number of six-locus genotypes and their relative frequency within the population did not differ significantly from the values expected for a sexually reproducing population. This genotypic structure is consistent with sexual reproduction generating the observed variation but vegatative reproduction and limited dispersal maintaining microgeographic genetic heterogeneity within the population. Diploid, six-locus genotypes were determined for 137 sporophytes. The sporophyte genotypic variation suggested that mating was occurring predominantly between female and male gametophytes within the same site. Fewer gametophyte genotypes were observed than were expected to be produced by sporophyte genotypes observed at each site, suggesting that genetical and/or ecological factors may be limiting the recruitment of new haploid gametophyte genotypes into the population.

ANT‐HILL VEGETATION IN ACIDIC GRASSLANDS IN THE GOWER PENINSULA, SOUTH WALES

SUMMARYThe vegetation of ant‐hill and adjacent pasture was compared in five acidic grasslands in the Gower peninsula, South Wales. The acrocarpous mosses Dicranum scoparium Hedw., Polytrichum juniperinum Hedw. and P. piliferum Hedw. were almost confined to the mounds but several perennials, including Anthoxanthum odoratum L., Luzula campestris (L.) DC, Potentilla erecta (L.) Rausch and Sieglingia decumbens (L.) Bernh., were much less abundant on ant‐hills than in the surrounding vegetation. The factors which influence the distributions of the plant species are discussed briefly. In considering the responses of plants to ant‐hills soil chemical and physical factors are probably less important than a plant's dispersal ability and capacity to withstand burial.

Capsule Expansion in the Hairy-Cap Moss, Polytrichum

In cultured explants of Polytrichum sporophytes, capsule expan- sion requires light. Red light is more effective in promoting expansion than white, blue, or green light of equal energy. The increase in capsule dry weight is a linear function of the length of the explant in the absence of dextrose for all lengths tested, and also in the presence of dextrose over the range 10-40 mm. In the absence of dextrose, capsule gain is a linear function of weight loss in the seta over the range in seta lengths 10-40 mm. With dextrose present, capsule gain has a nonlinear relationship to seta loss because dextrose suppresses seta loss relatively more than it enhances capsule gain, with increasing length of the explant. Polytrichum juniperinum Hedw. and P. ohioense Ren. & Card. were used in this study. Gametophytes and attached sporophytes were collected as turves during the winter and spring from Portland Arch, Indiana. All sporophytes were unexpanded, and each experiment is based on sporophytes of one age, only. The plants were freshly collected and grown in a greenhouse for a few days before each experiment, to condition them to the warmer temperature of the laboratory. At the start of an experiment, sporophytes were stripped of their calyptras and removed from the gametophytes, surface sterilized in 5% Clorox for 5 minutes, cut to length by removing the foot and a variable portion of the seta above the foot, and planted base down. Except where noted, explants were cut to 10 mm long. The length of the unexpanded capsule was estimated at 2 mm. The medium consisted of Voth's (1943) solution #5 solidified with 1% Difco Bacto Agar, with or without 1% dextrose. The explants were grown, one per 25 x 100 mm culture tube, for two weeks or longer at 23?C. Given an appropriate light regime, plants treated this way form

Photosynthesis and Respiration of Forest and Alpine Populations of Polytrichum juniperinum

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

Photosynthesis and Respiration in Germinating Spores of Polytrichum

Photosynthesis and Respiration in Germinating Spores of Polytrichum

The Effect of the Calyptra on Capsule Symmetry in Polytrichum juniperinum Hedw.

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

Lichens of the 1951 Foray to the North Shore of Lake Superior

POLYTRICHUM JUNIPERINUM Hedw. (B)-Burnt tract, abundant, Aug. 7, No. 3736; (B)-On burnt-over upland, common, tops being pecked (and presumably eaten) by White-crowned Sparrow, June 5, No. 3357; (B)Open, rocky ground in burnt tract, very common, June 21, No. 3434; (G)Damp, rather open hillside among young spruces, abundant, Aug. 26, No. 3909; (H)-Open, boggy glade among spruce woods, abundant, Sept. 15, No. 4017. POLYTRICHUM JUNIPERINUM var. ALPESTRE B. S. G. (A)-Opening in spruce woods, common, May 30, No. 3339. POLYTRICHUM PILIFERUM Hedw. (D)-Alpine meadow, Barrens, Aug. 15, No. 3843b. POLYTRICHUM COMMUNE Hedw. (H)-Open, boggy glade among spruce woods, abundant, Sept. 15, No. 4016.