Archive for Bryology
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The Chocó region in Colombia is one of the wettest rainforests regions in the world. Isolated for about 3 million years, it is known for its high rate of endemism in flowering plants, ferns, birds and butterflies. Bryophytes (mosses and liverworts) of this region, however, were very unsufficiently known. For this reason, a first survey of the bryoflora of the Chocó region was made in 1992 along a transect from sea level to 1800 m elevation. Apparently because of the high precipitation with up to 12 m annual rainfall, terrestrial species were found growing on bark or corticolous species on leaves. The cover of epiphytic bryophytes is higher than elsewhere, especially in the lowland forest which shows usually a low bryophyte cover. The percentage of mosses compared with that of liverworts is much lower than elsewhere. Mosses form only about 10% of the bryophyte cover in contrast to 40-50% in the according elevation in other rain forest regions.
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Plants variable in size and appearence, from a few mm to more than 10 cm tall, in loose to dense tufts. Stems erect, simple, rarely branched, radiculose, sometimes densely tomentose; rhizoids reddish-brown to whitish. Leaves erect-patent, sometimes curled when dry or falcate (sometimes erect and falcate expressions in the same species), short to longly lanceolate, often subulate; margins entire or serrate at leaf tips; costa single, percurrent to short excurrent, sometimes hyaline excurrent, filling 1/6 to 4/5 of leaf width, in transverse-section with median deuter cells and dorsal stereids, rarely hyalocysts, ventrally either stereids or more rarely hyalocysts; laminal cells usually smooth, occasionally bulging mammillose, cell walls smooth; alar cells differentiated or not, when distinct, hyaline or reddish brown, inflated, thin-walled or incrassate, basal laminal cells mostly rectangular, thin-walled or incrassate, occasionally pitted, upper laminal cells quadrate to rectangular or oval, leaf border present in some taxa. Vegetative propagation by microphyllous branches, deciduous leaves or stem tips, or anisophyllous brood leaves in the axils of the upper leaves. Dioicous or autoicous. Perichaetia terminal, or occasionally pseudolateral by stem innovations, perichaetial leaves often different in shape, from sheathing base subulate. Seta mostly elongate (1-4 cm), rarely short (<1 cm) or almost absent, erect, in few genera flexuose, cygneously curved and twisted. Capsule immersed to more commonly exserted, inclined to suberect or erect, symmetric to asymmetric, short long-cylindrical to ovoid-cylindrical or ovoid,, smooth or furrowed when dry and empty; stomata present or absent; annulus present or absent. Operculum conical to long-rostrate. Peristome single, teeth 16, mostly divided 1/2 or more toward base, vertically striate below, distally papillose to papillose throughout. Calyptra cucullate, smooth, naked, base entire or ciliate. Spores almost smooth to coarsely papillose.
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The development of and the changes in the classification of bryophytes are shown over the last two centuries. It is shown that, except for an early period, the bryophyte system was never totally revised but was always only slightly improved, in which the ideas of a bryophyte system has undergone some kind of evolution but was never drastically changed. Neither the evolution theory in the last century nor the results of cytology, phytochemistry, computerbased studies or genetics in this century had drastically altered the bryophyte system. The reasons for the never totally changed but always slightly improved classification of bryophytes seem to be that recognition of systematic units is based on certain principles such as hierachical classification, types and algorithms of comparison. Therefore it is postulated that no general changes in the classification of bryophytes are to be expected in the future.
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Germinating tests with bryophytes were undertaken with three moss species and two hepatic species. For the first time these tests were performed with aquaceous extracts of bryophytes in contrast to previous studies in which seeds were directly placed on moist bryophytes. First tests showed an inhibition of the germination rate in 3 species but an increase of the germination in one species. A second study revealed that aquaceous as well as alcoholic extracts in high concentrations inhibited the growth of cress, highly diluted extracts promoted the growth. Other authors found either only germination promoting effects or both, promoting and inhibiting effects. Experiments with compounds extracted from bryophytes cited in the literature had only growth inhibiting effects. Brachythecium rutabulum revealed growth inhibiting effects in a previous but growth promoting effects in this study. The conflicting results are hard to explain and should stimulate further more detailed studies. They maybe due to various combinations of different concentrations of bryophyte extracts, different bryophyte species, different pH and different seeds but also contamination by dust, soil, bacteria and fungi .
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Leptodontium styriacum shall be distinguished from the closely related L. flexifolium by the frequent occurrence of gemmae, leaves ending in a hyaline cell and larger laminal cells. A critical evaluation of these characters revealed that these differences are obsolete. Therefore both species are synonymised with the result, that L. flexifolium has a disjunct range between the oceanic parts of Europe and the Alps, a distribution pattern also found in several other species.
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Scopelophila cataractae, a species on heavy metal rich substrates, was first recorded for Europe in 1967 from Britain and subsequently recorded from many localities contaminated with heavy metal especially around zinc works. It was found in Germany on schist-walls nearby mines from the nineteenth century. This could indicate that the species was present in Europe already prior to 1967 but overlooked. Records even from solid rock nearby mines suggest a status as native species, however, the species had not been observed in the inrtensively floristically studied region before 1870.
136
The habitat as well as the unicellular thallus margins of Aneura maxima lead to the assumption that this species could be a hygromorphosis of A. pinguis. Therefore specimens of A. pinguis were cultivated in water. Even after four months the multicellular thallus margins were retained, which proved to be a stable character to separate A. pinguis from A. maxima. Therefore plants even with a small unistratose border, which are attributed to aquatic forms of A. pinguis, may belong to A. maxima. It is supposed that A. maxima was overlooked in Europe but regarded as aquatic forms of A. pinguis named as fo. rivularis. Such plants show unicellular thallus margins and are regarded as hygrophytic form of A. maxima. The presence viz. absence of an unicellular thallus margin seems to be a sufficient character to separate both species. The discussion about the width of the unistratose thallus margin is useless because the type of A. maxima has only 2-4 rows of unicellular cells and not 6-12 or more as attributed by European hepaticologists. This raises doubts whether the European material is identical with A. maxima rather with A. pellioides from Japan.
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Since 150 years, the surroundings of Meran in the Etsch valley (Prov. Alto Adige (Südtirol), Italy) are known as an extraordinary place for rare bryophyte species. It is an attraction for bryologists, who collect species, which are found in Europe only in a few places in the southern Alps. The region is especially well known by the fieldwork of Julius Milde, who stayed there 2 years and described some species as new. In spite of the bryological importance of this region, descriptions of this area as well comments on the phytogeographical background seem to lack.
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Based on collections of the author in February and March 2012, Notothylas breutelii, Syzigiella perfoliata, Campylopus lamellinervis. as well as the genus Riccia are reported as new to the Dominican Republic. Sixteen new provincial records are given. Updated and revised lists of the mosses of the Dominican republic as well as the province of La Plata are given.
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