Leaf Costa Research Articles

How to Recognize Mosses from Extant Groups among Paleozoic and Mesozoic Fossils

This paper describes a range of Paleozoic and Mesozoic mosses and assesses how far they can be referred to extant taxa at the family, ordinal, or class levels. The present study provides new data on Paleozoic mosses of the order Protosphagnales, re-evaluating affinities of some groups previously thought to be unrelated. The leaf areolation pattern, combined with the leaf costa anatomy, results in the subdivision of Protosphagnales into five separate families: Protosphagnaceae (at least six genera), Polyssaieviaceae (at least three genera), and three monogeneric families: Rhizonigeritaceae, Palaeosphagnaceae, and Servicktiaceae. We urge caution in referring Paleozoic and Early Mesozoic fossil mosses as members of Dicranidae and Bryidae, as they may belong to the extinct moss order Protosphagnales. Additional evidence supports the relation of the Permian genus Arvildia to extant Andreaeopsida. We segregate Late Palaeozoic and Early Mesozoic mosses that are superficially similar to extant members of either Dicranales or Polytrichales, into the artificial informal group of Archaeodicranids, distinguishing them from ecostate Paleozoic and Mesozoic mosses, which are combined here into another artificial informal group, Bryokhutuliinids. The latter includes the genus Bryokhutuliinia, widespread in contemporary Asia, from the Middle Jurassic to the Lower Cretaceous, as well as other superficially similar ecostate plants from different regions worldwide, ranging from the Upper Palaeozoic to the Lower Cretaceous. A list of Paleozoic, Mesozoic, and Eocene moss fossils suitable for age calibration in phylogenetic trees is provided.

Sciaromiopsis sinensis (Amblystegiaceae), revised to a member of Brachythecium (Brachytheciaceae)

Sciaromiopsis comprises a single species, S. sinensis, endemic to China. The genus is currently placed in the Amblystegiaceae, solely on the basis of gametophytic characters since its sporophytes are unknown. As a semiaquatic plant, the character of a strong leaf costa and marginal borders can aid S. sinensis to adapt drought as while as aquatic conditions. In this study, the phylogenetic position of Sciaromiopsis was revisited based on morphological and molecular phylogentic evidences of three datasets, the plastid rps4 dataset with 346 mosses species, the ITS dataset with 104 moss species and 82 plastid protein-coding gene dataset with 32 moss species. According to the morphological characters of gametophyte, the stable pattern of pseudoparaphyllia, leaf cells smooth and single costa of Sciaromiopsis are consistent with key characteristics of the Brachytheciaceae, the ovate-lanceolate leaves, differentiated alar cells and rhomboidal median leaf cells are consistent with key characteristics of the Brachythecium. Maximum likelihood and Bayesian analyses of both datasets of the rps4 gene and the 82 plastid protein-coding genes clearly indicated that Sciaromiopsis is a member of Brachytheciaceae. Sciaromiopsis sinensis is either clustered in a well supported clade among species of Brachythecium, Koponeniella and Myuroclada in the rps4 tree, or strongly supported as the sister to Brachythecium rivulare in plastid 82 gene tree. Maximum likelihood analysis of the nuclear ITS locus suggested that S. sinensis is nested within Brachythecium with moderate support. Thus, S. sinensis should be considered as a member of the Brachythecium, the diagnostic character of its leaf margin bordered by 5–8 rows of linear cells making it an easy distinction from other species of Brachythecium.

Heavy Metal Accumulation and Copper Localization in Scopelophila cataractae in Thailand

Four specimens of gametophores and protonemata of Scopelophila cataractae (copper moss) were collected from a stream in Doi Suthep-Pui National Park, Thailand in order to determine heavy metal accumulation and Cu localization. The order of total metal concentrations in the protonemata and leaf cell surfaces of S. cataractae was Fe > Zn > Cu. Significant Cu values (> 400mg kg-1) were found in both gametophores and protonemata. Growth substrates were considered as a key source of heavy metals in the sampling stream. X-ray spectrometry (EDS micro-analyser) detected the localization of ten elements (C, O, Mg, Al, Si, Ca, S, Cu, Zn and In); substantial atomic percentages of Al, Cu and Zn were noted in leaf surfaces and protonemata. These metallic elements were found in highest proportion. To some extent, cell surfaces at the basal leaf costa showed the highest peak value compared to medial and apical leaf portions (≈ 4.3 at.%). This Cu moss can be used as a bioindicator to reflect anthropogenic activities in stream ecosystems.

Ecological Adaption of Leaf Costa of Bryophyte from Alpine Periglacial Region

Ecological Adaption of Leaf Costa of Bryophyte from Alpine Periglacial Region

Phantomia vadimii(Dicranaceae), a New Moss Genus and Species from Northern Vietnam

Phantomia vadimii S. He & W. R. Buck, a new moss genus and species, is described from Lao Cai Province, northern Vietnam. The new taxon is characterized by its abruptly convolute leaf shoulders; the presence of a median row of stereid cells in the upper lateral costal cross sections; a weakly differentiated marginal border at the leaf base; and the absence of a central strand in the stem. The new genus shares some characteristics with Chorisodontium (Mitt.) Broth. in having a narrow basal costa that flares outward at the midleaf and persistent, inflated alar cells. It also has an anatomical similarity to the leaf costal cross sections (especially the upper leaf costa) of Dicranodontium Bruch & Schimp. The similarities and differences of the new genus in comparison with the genera of Campylopodioideae and Dicranoideae are discussed.

Grimmiaceae in the Early Cretaceous: Tricarinella crassiphylla gen. et sp. nov. and the value of anatomically preserved bryophytes.

Widespread and diverse in modern ecosystems, mosses are rare in the fossil record, especially in pre-Cenozoic rocks. Furthermore, most pre-Cenozoic mosses are known from compression fossils, which lack detailed anatomical information. When preserved, anatomy significantly improves resolution in the systematic placement of fossils. Lower Cretaceous (Valanginian) deposits on Vancouver Island (British Columbia, Canada) contain a diverse anatomically preserved flora including numerous bryophytes, many of which have yet to be characterized. Among them is the grimmiaceous moss described here. One fossil moss gametophyte preserved in a carbonate concretion was studied in serial sections prepared using the cellulose acetate peel technique. Tricarinella crassiphylla gen. et sp. nov. is a moss with tristichous phyllotaxis and strongly keeled leaves. The combination of an acrocarpous condition (inferred based on a series of morphological features), a central conducting strand, a homogeneous leaf costa and a lamina with bistratose portions and sinuous cells, and multicellular gemmae, supports placement of Tricarinella in family Grimmiaceae. Tricarinella is similar to Grimmia, a genus that exhibits broad morphological variability. However, tristichous phyllotaxis and especially the lamina, bistratose at the base but not in distal portions of the leaf, set Tricarinella apart as a distinct genus. Tricarinella crassiphylla marks the oldest record for both family Grimmiaceae and sub-class Dicranidae, providing a hard minimum age (136 million years) for these groups. The fact that this fossil could be placed in an extant family, despite a diminutive size, emphasizes the considerable resolving power of anatomically preserved bryophyte fossils, even when recovered from allochthonous assemblages of marine sediments, such as the Apple Bay flora. Discovery of Tricarinella re-emphasizes the importance of paleobotanical studies as the only approach allowing access to a significant segment of biodiversity, the extinct biodiversity, which is unattainable by other means of investigation.

Inventarization Epiphytic Mosses in Hutan Lumut Area “Dataran Tinggi Yang”, Wildlife Preserve Argopuro Mountain

Mosses are group of non-vascular plant, small size, and able to growth in many substrates. Epiphytes are organism witch growth at wood surface of living plant. Epiphytic mosses has some advantages, there are out of range from terestial organism and to get more optimaly sun light. One of place which has suitable conditions for this research is in Wildlife Preserve “Dataran Tinggi Yang”, Argopuro Mountain. This research purpose to get known about species of epiphyte mosses and morphological characteristic each species of epiphytic mosses in Wildlife Preserve “Dataran Tinggi Yang”, Argopuro Mountain. The result of identification and characterization obtained 17 families and 25 species of epiphytic mosses. The main characteristic of mosses are leaf position, leaf form, and leaf costa.

Testing hypotheses on suprageneric relationships and morphological evolution in the Leucobryaceae (Bryophyta)

We studied suprageneric relationships and patterns of morphological character evolution within the moss family Leucobryaceae, based on phylogenetic analyses of markers from all three genomes and representatives from 11 out of 14 genera. Three main lineages are strongly supported within the Leucobryaceae, which display different morphologies of the leaf costa, two dicranoid clades (Campylopus clade and Dicranodontium clade) and a leucobryoid clade. Character evolution analyses resolved the leucobryoid morphology as a synapomorphy for the leucobryoid clade and provided data to evaluate generic circumscriptions within the family. Patterns of molecular variation, species richness, geographical distribution, ecological amplitude and variation in costa structure seem to covary: The two lineages with the most modified morphologies (deviating from the basic dicranoid type; Campylopus and leucobryoid clades) are also the most molecularly variable, species diverse, and occupy the broadest distributions and widest variety of habitats. Most sampled genera have clear morpho-molecular circumscriptions, except Campylopodiella, Dicranodontium and Leucobryum. For the latter, two alternative topologies were resolved (Leucobryum monophyletic or the Asian genera Cladopodanthus and Schistomitrium nested within Leucobryum).

The moss Helicophyllum torquatum (Bryopsida: Helicophyllaceae) has survived since at least the Miocene

Classification of incompletely preserved fossils is a challenging task. We describe a moss fossil preserved in a piece of Miocene Dominican amber and assign it to the monospecific extant genus Helicophyllum. According to the published divergence time estimates, Helicophyllum originated in the Late Cretaceous, but so far no Helicophyllum fossils have been found. The Helicophyllum fossil consists of several sterile gametophytes with dimorphic leaves in two lateral and one ventral series;the lateral leaves being lingulate and obtuse and the shorter ventral leaves ovate-lanceolate. All leaves have a percurrent single costa and hexagonal to subquadrate, papillose cells. The fossil differs from extant Helicophyllum torquatum only by its slightly narrower leaf costa. Based on the extensive morphological overlap of the fossil and extant Helicophyllum specimens in other gametophytic characters and considering the Mesozoic origin of the genus, we propose an assignment of the fossil to the extant species H. torquatum, thereby accepting a minimum age of the species of 15 My. We discuss the problems of assigning fossils to extant species and propose to take into account not only morphological evidence but also evidence from divergence time estimates.

Plagiomnium guizhouense Y.-J.Yi & S.He sp. nov. (Mniaceae) found in southwestern China

A new species of Plagiomnium (Mniaceae), P. guizhouense Y.-J.Yi & S.He from Guizhou, China is described and illustrated. The new species is similar to P. affine in having spinosely serrate leaf margins with teeth consisting of up to 4 or more cells, a broadly elliptic leaf shape, and a decurrent leaf base, but is distinguished from the latter species by having a cuspidate leaf apex, broader marginal differentiation with borders consisting of 4–5 rows of linear, thick-walled cells, strongly ciliate marginal teeth that are sometimes branched and up to 7 cells long in upper fertile stem leaves and perichaetial leaves, and a much shorter leaf costa that ends just above mid-leaf in the lower leaves.

Membrane stability of the desert moss Syntrichia caninervis Mitt. during desiccation and rehydration

Syntrichia caninervis Mitt. is the dominant species in the moss crusts of the Gurbantunggut Desert, a cold, northern desert of Central Asia. Most studies of bryophyte desiccation tolerance have been of Tortula (Syntrichia) ruralis. The two species are closely related and any physiological work on one is likely to be relevant to the other. Changes in membrane structures in this species were monitored under varying conditions of water stress in this study. Microscopical and physiological tests were conducted. No significant changes in electrical conductivity of the rehydration water were observed either during dehydration or rehydration. Electron micrographs of the fine-structure of leaf cells were obtained through a drying–re-wetting cycle. Major changes in cell ultrastructure were observed over time but there was no evidence of membrane damage during either desiccation or rehydration. Three possible explanations for disorganized or disrupted membranes in the desiccated state are considered: (1) S. caninervis has special morphological and anatomical characteristics (e.g. strong leaf costa which can transport water during the recovery state) that allow it to survive in an hostile, arid environment, and cellular structures that remain intact in the desiccated state permitting membrane integrity to be rapidly regained during rehydration; (2) the moss quickly becomes dormant during dehydration but maintains a certain level of membrane integrity; and (3) during desiccation, rapidly and continuously increasing amounts of both soluble sugar (major ‘constitutive’ protective substances) and free proline contribute to membrane stabilization.

Indopottia irieandoana sp. nov. (Pottiaceae) from Doi Inthanon, northern Thailand

Indopottia irieandoana H.Akiyama sp. nov. is reported on the basis of two specimens from Doi Inthanon, northern Thailand, as a second species of a genus recently described from southern India. The lack of a peristome precludes unambiguous familial placement based on morphology, but phylogenetic analyses of sequences from a chloroplast and a mitochondrial locus place the new taxon, with strong support, in the Pottiaceae. Its epiphytic habitat on a tree trunk and a branch near the crown of an emergent tree and a strangler tree, respectively, along with morphological features such as spatulate leaves, a single dorsal stereid in the leaf costa, smooth laminal cells, long rostrate opercula, and eperistomate, upright capsules point to a close relationship to Indopottia zanderi. The morphology is compared with that of related genera. A key to similar genera and species is provided.

Morphological Adaptations to Drought and Reproductive Strategy of the Moss Syntrichia caninervis in the Gurbantunggut Desert, China

The biological soil crusts (BSCs) in the Gurbantunggut Desert, the largest fixed and semi-fixed desert in China, feature moss-dominated BSCs, which play an indispensable role in sand fixation. Syntrichia caninervis Mitt. (S. caninervis) serves as one of the most common species in BSCs in the desert. In this study we examined the morphological structure of S. caninervis from leafy gametophyte to protonema using light and scanning electron microscopy (SEM). We also examined the relationships between the morphological structure of S. caninervis and environmental factors. We found that: (1) this moss species is commonly tufted on the sand surface, and its leaves are folded upwards and twisted around the stem under dry conditions; (2) the cells on both upper and lower leaf surfaces have C-shaped dark papillae, which may reflect sunlight to reduce the damage from high temperature; (3) the leaf costa is excurrent, forming an awn with forked teeth; and (4) the protonema cells are small and thickset with thick cell walls and the cytoplasm is highly concentrated with a small vacuole. In addition, we also found that the protonema cells always form pouches on the tip of the mother cells during the process of cell polarization. Our results suggest that S. caninervis has, through its life cycle, several morphological and structural characteristics to adapt to dry environmental conditions. These morphological features of S. caninervis may also be found in other deserts in the world due to the world-wide distribution of the species.

Indusiella (Ptychomitriaceae) in South America

Indusiella, previously known from North America (Alaska), central Asia and North Africa (Chad), is reported for the first time for South America. A new species, Indusiella stellata, is described based on one specimen collected from Potosí Department in Bolivia. In addition, I. thianschanica is reported for the first time from Argentina and Bolivia. The new taxon is distinguished from I. thianschanica by its immersed and gymnostomous capsule, leaf costa without dorsal stereids and 8–20 guide cells in (2–)3–4 layers in the basal leaf region, and stems without a central strand. Both species are described and illustrated. The description of Indusiella is reëvaluated and a key to the species of the genus is provided.

Environmental Factors Potentially Affecting Character States in Pleurocarpous Mosses

Abstract The frequencies of states of 86 characters in 439 pleurocarpous moss species from all over the world are compared across climatic zones, general habitats, and the gradient wetland versus non-wetland. Forty-four percent of the characters are influenced by climatic zone, 35% by general habitat, and 23% by the wetland vs. non-wetland gradient. Most of the differences in character state frequencies among environmental categories seem to relate to two complex functions: 1) water conduction and retention, as expressed by differences in frequencies of states of the characters stem central strand, leaf orientation, leaf costa type, alar cells, paraphyllia, pseudoparaphyllia, inner perichaetial leaf plications, vaginular paraphyses, operculum type, stomatal pore, and possibly seta length and 2) spore dispersal, expressed by variation in frequencies of character states related to capsule shape and orientation, annulus, exostome and endostome appearance, spore size and maturation time, and possibly seta len...

Nuclear Ribosomal DNA Variation in Leucobryum glaucum and L. albidum (Leucobryaceae): A Preliminary Investigation

Leucobryum glaucum and L. albidum are generally distinguished by quantitative differences in plant height, leaf length, and transverse sectional leaf anatomy. Although extremely small plants can be readily identified as L. albidum, and large plants can be confidently assigned to L. glaucum, intermediate forms are common and many identifications are arbitrary. We amplified approximately 815 bp of the nuclear ribosomal DNA ITS from plants varying in size, and cut the products with three restriction endonucleases (Hhal, Hinfi, and Taql). Two DNA haplotypes were detected in a sample of 23 plants growing at a forested site in Durham, North Carolina. All plants with leaves 5.0 mm in length or shorter had one haplotype, and all plants with leaves longer than 5.0 mm had the other haplotype. Our results support the interpretation that L. albidum (small plants) is genetically discontinuous with L. glaucum (large plants), at least in the limited area from which we sampled. Leucobryum is one of approximately eight genera in the Leucobryaceae (Yamaguchi 1993), which is comprised of acrocarpous mosses with haplolepideous peristomes and multistratose leaves. Members of the family are separated from the Dicranaceae on the basis of their distinctive leaf structure. The leaf costa in leucobryoid species, which comprises most of the leaf, consists of a central layer of small, often diamond-shaped chlorophyllose cells (chlorocysts) and several layers of hyaline cells (leucocysts) above and below the chlorocysts. Leucobryum includes approximately 180 species (Brotherus 1924; Yamaguchi 1993), some of which are common components of temperate and tropical forest communities. Leucobryum species of Europe and North America are often called pin cushion mosses because of the rounded colonies they form. Two or three species of Leucobryum occur in eastern North America (Anderson et al. 1990; Crum & Anderson 1981). Leucobryum glaucum (Hedw.) Angstr. ranges from Newfoundland west to Manitoba, and south to the Gulf of Mexico. The species also occurs abundantly across northern Europe and Asia, east to Japan (Yamaguchi 1993). The other North American species, L. albidum (Brid.) Lindb., is restricted to the eastern United States and Canada, and occurs in the Caribbean region and Central America (Crum & Anderson 1981). A third species, L. antillarum, has been reported from the Gulf coast region of the United States, but Crum & Anderson (1981) exclude it from the flora, arguing that North American plants attributed to this species cannot be distinguished from L. glaucum. Nevertheless, Anderson et al. (1990) included L. antillarum in their most recent checklist of North American mosses, and the problem requires further study. Leucobryum glaucum and L. albidum have been distinguished by size of the gametophytes and the number of leucocyst layers below the single layer of chlorocysts, as seen in transverse sectional view at or near the leaf base (Crum & Anderson 1981). The larger species, L. glaucum, is said to form deeper cushions (2-9 cm high according to Crum & Anderson 1981), and the leaves are 3-8 mm long, with 3-4 layers of leucocysts below the chlorocysts. In contrast, L. albidum is described as forming cushions rarely more than 1 cm high, with leaves less than 4 mm long and having only 2-3 layers of leucocysts below the chlorocyst layer. Sporophytes are considerably more common on smaller plants that correspond to L. albidum than on larger plants that fall within the range of morphological variation generally attributed to L. glaucum. The reason(s) for this difference in sporophyte formation has not been studied. Both species are dioicous and are reported as having dwarf males that grow epiphytically among the perichaetial bracts of the females (Crum & Anderson 1981; Smith 1978; Yamaguchi 1993). In L. glaucum, male plants vary in size from extremely dwarfed and epiphytic to only slightly smaller than the females (Yamaguchi 1993). The situation is less clear in L. albidum because no systematic studies have been conducted, but it has been suggested that the males 0007-2745/98/272-277$0.75/0 This content downloaded from 157.55.39.95 on Sat, 11 Jun 2016 05:04:58 UTC All use subject to http://about.jstor.org/terms 1998] PATTERSON ET AL.: DNA OF LEUCOBRYUM 273 5'>TCGATGAAGAACGCAGCG TCCGTAGGTGAACCTGCGG<3'

On Dichodontium pellucidum and D. olympicum

A detailed morphological comparison was made between Dichodontium pellucidum (Hedw.) Dix. and D. olympicum Ren. &amp; Card, in search for new taxonomic features. The two species are found to differ distinctively in cellular details of the ventral surface of the leaf costa, exothecial cells, and in sexuality. A distribution map is prepared for D. olympicum, a western North American endemic. Comparisons of anatomical features are also made between the two taxa of Dichodontium and European specimens of Oreoweisia serrulate (Funck) DeNot. The results support the assertion that all North American specimens of Oreoweisia serrulata should be referred to Dichodontium pellucidum.

The Moss Genus Isotheciopsis

The Moss Genus Isotheciopsis

Mnium nudum in Japan

Mnium nudum is reported as new to Japan from specimens collected in Nagano Prefecture. Mnium nudum Williams ex Britt. & Williams (1900), originally described from Idaho and Montana, is common in British Columbia, Washington, and no doubt elsewhere in the Pacific Northwest. Like so many other species of that area, M. nudum also occurs in Japan. Specimens collected on soil and humus in coniferous forests on Mt. Yatsu and Mt. Kisokoma, Nagano Prefecture, were distributed as numbers 374 and 533 in Musci Japonici under the name M. subglobosum B.S.G. The plants resemble M. subglobosum (or, more properly, M. pseudopunctatum Bruch & Schimp.) in having a relatively short leaf costa, but they are dioicous rather than synoicous. Mnium nudum, a member of the M. punctatum complex, can be recognized with ease by its naked stems which are particularly noticeable in male plants because the lower leaves are reduced to scales and the uppermost leaves are abruptly enlarged and crowded in a perigonial rosette. The rather large leaves are pale to dark green, shiny, scarcely altered on drying, rounded to elliptic, broadly rounded and 1 National Museum of Canada, Ottawa, Ontario. This content downloaded from 207.46.13.33 on Wed, 23 Nov 2016 04:20:06 UTC All use subject to http://about.jstor.org/terms 1965] CRUM: MNIUM NUDUM 119 not at all mucronate at the apex, rather weakly bordered, with the costa ending well below the leaf apex and cells hexagonal and not or only slightly elongate. Other less easily observed differences are given in Lawton's (1964) excellent description and illustrations.

The Genus Hymenostomum in North America

Have we this genus in North America ? This depends somewhat on the point of view. I think we have here a moss which in Europe passes for a Hymenostomum. HYMENOSTOMUM R. Br. in Trans. Linn. Soc., 18I9. The following is the historical view of this genus drawn up by Prof. Limpricht in Laubmoose, I, p. 223, 224: t Hymenostomum (membrane-mouth or-orifice), founded on Gymnostosmum microstomum Hedw., is characterized by the author as a natural genus not merely by reason of characteristic external appearance but by reason of the structure of the capsule. The authors of Bryologia Germanica (1823) emphasize its affinity with Weisia viridula, and they include besides H. rutilans (Hedw.), also H. squarrosum Bryol. Germ., H. obliquum N. v. E., H. brachycarfon Bryol. Germ., H. subglobosumn Bryol. Germ., and H. crisfatum Bryol. Germ.; however the last species is withdrawn again in I83I by the authors in Bryol. Germ., i . 2. p. 33. Huebener in 1833 considers H. obliquum and .H. brachycarfon as varieties, recognizes Phascum rostellatum Brid. as a Hymenostomum, designates it however as H. microstomum var. /. inutilatum Heuben. In Bry. Eur., 1846, Gymnostomum tortile Schwaegr. is after Fuernroh's example described as a Hymenostomum, however H. rutiians (Hedw.) is made a synonym of W[eisia mucronulata Bruch., and H. subglobosum Bryol. Germ. a synonym of UZeisia viridula; further H. rostellatum is treated as an Astomum, and by error H. crisfpatum Bryol. Germ. is also removed. C. Mueller in his Synopsis (I849) treated Hymenosfomum as a subgenus of Weisia; so also Juratzka (1882). Schimper in I86o puts it as a subgenus under Gymnostomum, yet G. rostellatum is counted in; in the second edition of the Synopsis (1876) it is again raised to the rank of a genus and H. unguiculatum Phil. is added: by gross error H. crisiatum Bryol. Germ. and H. murale (Spruce) are placed here. In Milde, who followed Lindberg, the genus is withdrawn in 1869, and its species are thrown in the subgenus Euweisia C. Muell, emend. Lindberg, in I879. considered Hymenostomuzu, including Euweisia C. Muell. and Astormum (Systegium) as a subgenus of ,Mollia Schrank emend., a genus which in respect to structure of capsule and the anatomy of its stem and of leaf costa comprises in its limits diverse elements. Since according to present views a valid taxonomic arrangement cannot be founded on the structure of vegetative organs merely, Hymenostomum is entitled to generic rank, for here in the so-called hymenium of the spore case we find a structure which has its analogue only in the drumhead, (the epiphragm or diaphragm) of the Polytrichacele. Strictly speaking H. microstomum and H. squarrosum are the only representatives within our territory, for H. rostellatum may be viewed as an Astomum and H. tortile probably does not belong here at all. That H unguiculatum Phil. represents a Trichostomum mutabile with rudimentary peristome is known; yet Hymenostomum MAuelleri Bruch from Corsica (Flora, 1829, t. 2