Fifteen species of mosses are reported as new to Costa Rica, five of those are new to Central America. These are: Paraleucobryum albicans (Schwaegr.) Loeske, Philonotis elongata (Dism.) Crum & Steere, Leskeodon cubensis (Mitt.) Th?r., Hookeriopsis dimorpha (C.M.) Broth. and Isopterygium machrisianum (Crum) Irel.

Porotrichum perplexans Dix. from Central China is reduced to synonymy with Homaliodendron papillosum Broth.

Four types of asexual reproduction in Plagiochila and the Plagiochilaceae are known: propagules, caducous leaves, gemmae and cladia. Plagiochila pluma Steph. has caducous leaves and teeth with regenerants. The terms for asexual reproduction modes in liverworts are briefly discussed and new definitions proposed.

Cheilolejeunea subgenus Xenolejeunea Kachroo & Schust. is emended to account for variability observed in stem anatomy and lobule structure. Cheilolejeunea subgenus Tegulilejeunea Schust. is reduced to synonymy with subgenus Xenolejeunea. A new sectional classification of subgenus Xenolejeunea is proposed (sections Gigantae, Meyenianae, and Xenolejeunea). A key distinguishes among the sections and the 10 species accepted in the subgenus, which is known from Australasia, Oceania and tropical Asia. A nomenclator and discussion is provided for each species. Comments on excluded species conclude the treatment

This is the first contribution on the moss flora of Xishuangbanna, southern Yunnan Province, one of the main tropical areas in China. This rich moss flora shows a similarity to that of Southeast Asia and the Himalayas.

The genera Meteoridium and Zelometeorium are described and illustrated from 73 collections made by the author in Bolivia. Barbella tenuissima (Hook. & Wils.) Fleisch. is transferred to the genus Meteoridium as Meteoridium tenuissimum (Hook. & Wils.) M. Lewis comb. nov. Due to its hypnobryoid peristome and other characters, the genus Meteoridium is placed in the Brachytheciaceae. Meteoridium remotifolium (C. M?ll.) Manuel shows marked variation over its altitudinal range and four ecoforms are recognized. Distribution records show that the species of these two genera have distinct ranges, with only Meteoridium remotifolium overlapping the ranges of the other species. Habitat data shows that none of the species treated are obligate epiphytes, and that they grow equally well in terrestrial habitats.

Breutelia microdonta (Mitt.) Broth., described originally from Brazil, is the oldest name for a disjunct widespread tropical species that includes as synonyms B. angustifolia Rehm. ex Sim of Southern Africa and B. merrillii Broth. of the Philippines. Breutelia kilaueae (C. Muell.) Broth. of Hawaii is considered a synonym of the austral Pacific species B. affinis (Hook.) Mitt., and B. brachyphylla Broth. of Ecuador is reduced to synonymy under the North Andean B. squarrosa Jaeg. Breutelia anacolioides Herz. of Bolivia is removed to Philonotis as a synonym of the North Andean P. incana (Tayl.) H. Robins. Differences in spore ornamentation offer an additional character distinguishing Breutelia from Philonotis.

A bryophyte inventory along an altitudinal gradient on Cerro Pirre (1200 m), Dari?n National Park, Panama, demonstrates that the different rain forest types along the gradient (inundatedlowland, hillside-lowland, submontane, montane elfin forest) have very different species assemblages. The montane forest has the largest number of exclusive species and the largest bryophyte biomass. Species richness is greatest in the submontane forest. The bryophyte flora of Cerro Pirre is not exceedingly rich in species owing to the rather low elevation of the mountain and the seasonal climate in the adjacent coastal plain. Nevertheless, the distinct altitudinal diversification and the occurrence of a considerable number of rare hepatic taxa, demonstrate the importance of Dari?n National Park as an area of plant conservation. Forty hepatic species are reported as new to Panama.

Lichen exploration of the Upper Mazaruni District, Guyana yielded 273 species, of which 179 were found for the first time in the Guianas and 13 were as yet undescribed. A list of all taxa encountered is presented, with indications of habitat and distribution in the investigated area as well as first descriptions for the following 7 species: Buellia aptrootii, Byssoloma farkasii, Myriotrema guianense, M. neofrondosum, M. subdactyliferum, Ocellularia astrolucens, and Thelotrema albomaculatum. Mazosia bambusae is recorded for the first time from the Neotropics. The richest areas for lichens appear to be the rocky tablelands with scrub vegetation on top of the lower mountains. The slopes of Mount Roraima are of special interest because they support some montane species which are unlikely to be found elsewhere in the Guianas; otherwise they are less rich in lichens, probably because of the high humidity, which favours bryophyte growth.

The neotropical genus Potamium as described by Mitten (1869) included species that had little more in common than a growth form adapted to a semi-aquatic habitat. Brotherus divided the genus in section Eu-Potamium and section Potamiopsis, based on peristome characters. This study shows that all species of section Eu-Potamium belong to Sematophyllum, including P. lonchophyllum which was designated as lectotype of Potamium by Buck (1990). In section Potamiopsis two species are recognized: P. vulpinum (Mont.) Mitt. (syn. nov.: Sematophyllum maguireorum Buck) and P. deceptivum Mitt. (syn. nov.: P. leucodontaceum (C.M?ll.) Broth., Meiothecium negrense Mitt. and Maguireella vulpina (Mont.) Buck). The genus Potamium is characterized by capsules with an endostome consisting of a low basal membrane and filiform segments, which are often reduced in P. deceptivum. P. vulpinum is designated as lectotype of Potamium and the lectotypification of Buck is rejected. Descriptions, illustrations and a key are provided to the species of Potamium and allied semiaquatic taxa of Sematophyllum.

A synopsis is provided of 88 species in 17 genera currently recognized in Lejeuneaceae subfamily Ptychanthoideae sensu lato (including Nipponolejeunea) of Asia. Taxonomic novelties include Thysananthus flavescens (Hatt.) comb. nov. (for Mastigolejeunea flavescens (Hatt.) Mizut.), Spruceanthus macrostipulus (Steph.) comb. nov. (for Archilejeunea macrostipula (Steph.) Verd.) and the reduction of Platylejeunea Mizut. to synonymy under Lopholejeunea. The ptychanthoid flora of Asia has more species but fewer genera than the neotropical flora. Moreovere, the taxonomic make-up of the two floras is very different, Asia being the centre of diversity for the tribe Ptychantheae whereas the New World is particularly rich in Brachiolejeuneae. The larger number of neotropical genera reflects the unusually high generic diversity in the New World (Schuster 1990). The high species richness in Asia is probably due to a greater latitudinal extension of the rain forest in the Far East as compared with the New World. 22% of the ptychanthoid species of the Far East are “non-tropical”, whereas in the New World it is less than 2%. Contrasting biogeographic trends are seen among the endemic genera of the two subfamilies of Lejeuneaceae in Asia, Ptychanthoideae and Lejeuneoideae. In Ptychanthoideae the endemic genera are largely restricted to the subtropical and temperate areas of Asia and the majority are also known as fossils in Eocenic amber of Europe (Ginkgo-type distribution). They are considered to be palaeoendemic, relictual groups. Endemic genera of Lejeuneoideae, however, occur mainly in the tropical rain forests of the Malesian archipelago, are often highly specialized and are lacking in the fossil record. They should have co-evolved in the Tertiary with the rain forest and are considered neoendemics. Ptychanthoideae seem to be older than Lejeuneoideae and presumably already existed in the Mesozoic before the break-up of Laurasia and Gondwanaland

Twenty-eight species of epiphyllous liverworts were identified from twenty-five sites in Kowloon Peninsula, Hong Kong. Twenty-four of these species are new records to Hong Kong, while four of them are new epiphyllous records to the Chinese mainland. The majority of the sites are located between 30-200 m above sea level, representing the lowest altitude of epiphyllous liverworts found in the Chinese mainland. Characteristics of the host plants bearing epiphyllous liverworts are briefly discussed. The following new combination is proposed: Cololejeunea pseudolatilobula (Chen & Wu) But & Gao comb. nov. (Pedinolejeunea pseudolatilobula Chen & Wu).

Twenty-two species of bryophytes are reported from Fernando de Noronha. One of these, Fissidens veracruzensis Pursell, has not been reported previously from Brasil.

A survey of the literature and a few unpublished identifications of recent collections indicate that 426 taxa have been reported from Costa Rica, including Cocos Island. The distribution of each taxon is indicated by province and parameters are given for most localities within each province.

88.Campylopus hildebrandtii (C. Müll.) Jaeg. is reported as new to Ethiopia. 89. The combination Campylopus flexuosus (Hedw.) Brid. var. incacorralis (Herz.) J.-P. Frahm is validated. 90. Campylopus sedgwickii Dix., a species hitherto regarded as endemic to Sri Lanka, is recognized as a synonymous with C. recurvus (Mitt.) Jaeg. 91. The Campylopus fragilis complex in SE-.Asia has been revised. It consists of C. fragilis (Brid.) B.S.G. in southern China, C. goughii (Mitt.) Jaeg. occurring from southern India to Sikkim and Bhutan and C. zollingerianus (C. Müll.) Bosch & Lac. occurring from Indonesia to the Philippines and also in Hawaii. Campylopus zollingerianus has proved to be the legitimate name for C. boswelii (C. Müll.) Par. and C. crispifolius Bartr. and not for C. goughii. All three species are distinguished mainly by the shape of the upper laminal cells only and accordingly, C. goughii and C. zollingerianus are placed as geographical vicariant races as subspecies to C. fragilis.

Seven species of Radula are reported from the Galapagos Islands, including Radula santacruziana spec. nov. The majority of the species are common and widespread in the neotropics; two (including the new species) are endemic to the Galapagos. R. cornucopiae Spruce and R. mollis Lindenb. et Gott. are reduced to synonymy, resp. under R. episcia Spruce and R. quadrata Gott. et al.

The species of Octoblepharum occurring in Central America have been critically examined. Six are recognized as valid species: O. albidum, O. cocuiense, O. cylindricum, O. erectifolium, O. pulvinatum and O. stramineum. Synonyms are given for these species: O. longifolium = O. albidum; O. mittenii, O. fragillimum, O. pellucidum and =O. pulvinatum var. angustifolium are synonyms of O. cocuiense; O. juruense and O. densum = O. pulvinatum and O. purpureo-brunneum = O. stramineum. All species are widely distributed in the area except for O. cylindricum and O. stramineum that are known only from Belize and Panama respectively.

Of the 65 species of Campylopus known from tropical America, 33 are andine in distribution, 16 are found only in SE Brazil, 8 have wide ranges through Central and South America, 3 species are disjunct in SE-North America and Brazil, 3 are confined to the Caribbean and one species belongs to the circum-pacific and one to the tethyan element. For different parts of the Neotropics, the composition of phytogeographical elements is calculated. For the first time, bryophyte distributions are compared to the Pleistocene forest refuges proposed by zoologist and phanerogamists. The distribution of several rainforest species of Campylopus coincides with the major part of the montane refugia. Using an interpretation of the present-day ranges, a hypothetical survey is given of the origin and evolution of this genus in tropical South and Central America. The ranges of part of the species can be explained only by long distance dispersal, while the ranges of other species seem to be relictual.

A new moss genus and species, Gradsteinia andicola, is described from the northern Andes of Colombia. It is an aquatic moss known sterile and characterized by 1) oblong or oblong-ovate, concave, cucullate and recurved-apiculate leaves with a very strong and variable costa that is basically single but commonly repeatedly branched and spurred from the base, giving the leaves a polycostate appearance; 2) thick-walled, porose and irregularly uni- to multistratose lamina cells; 3) bicellular axillary hairs; 4) the presence of incomplete limbidia; 5) the absence of paraphyllia, pseudoparaphyllia, central strand and alar cells. Until the sporophyte of Gradsteinia becomes known, this very distinct genus is tentatively placed in the family Donrichardsiaceae, based primarily upon the presence of variously multistratose leaf laminae and leaf areolation.

A floristic and ecological study of bryophytes and macrolichens in different lowland rain forest types around Mabura Hill, Guyana, South America, yielded 170 species: 52 mosses, 82 liverworts and 36 macrolichens. Lejeuneaceae account for about 30% of the species and are the dominant cryptogamic family of the lowland rain forest. Special attention was paid to the flora of the forest canopy, by using mountaineering techniques. It appeared that 50% of the bryophyte species and 86% of the macrolichens occurred exclusively in the canopy. Dry evergreen 'walaba' forest on white sand is particularly rich in lichens whereas the more humid 'mixed' forest on loamy soil is characterized by a rather rich liverwort flora. More species are exclusive to the mixed forest than to dry evergreen forest due to the 'canopy effect', i.e. the occurrence of xerophytic species in the outer canopy of both dry and humid forests. Furthermore, canopy species have wider vertical distributions on trees in the dry evergreen forest than in the mixed forest, due to the more open canopy foliage of the dry evergreen forest.

Based on a study of ca. 120 Fissidens species covering all sections and subgenera, three types and costae are recognized. One type is characteristic of sect. Amblyothallia and of F. asplenioides, F. fasciculatus and F.plumosus (the fasciculatus group); the second of subg. Serridium, subg. Fissidens sect. Crispidium and F. grandifrons (subg. Pachyfissidens) and the third type of subg. Fissidens sect. Fissidens, sect Aloma, sect. Crenularia, sect. Semilimbidium, sect. Pycnothallia, and sect. Areofissidens, subg. Octodiceras, and subg. Sarawakia

A synopsis and key emphasizing vegetative characters are provided for the 967species (in 36 genera) of Lejeuneaceae with undivided underleaves recorded from the New World

The Holomitrium-complex (consisting of Holomitrium, Eucamptodontopsis, and Schliephackea) is a group of closely related genera in the Dicranaceae characterized by five features: 1. a strong single costa, 2. well developed alar cells, 3. long, sheathing perichaetial leaves, 4. erect capsules, and 5. undivided peristome teeth. Holomitrium sinuosum is newly described. Dicranoloma brittonae is transferred to Eucamptodontopsis. Holomitrium standleyi is a synonym of H. arboreum. Breedlovea chiapensis is a synonym of Holomitrium pulchellum and the genus Breedlovea is placed into the synonymy of Holomitrium.

Desmotheca Lindberg was proposed in 1872 as a replacement name for the illegitimate Cryptocarpon Dozy & Molk. (1844) and Cryptocarpus Dozy & Molk. (1846). Seven names have been placed in these genera, from which two species appear to be taxonomically valid. Desmotheca apiculata (Dozy & Molk.) Card. occurs from New Caledonia and New Guinea west to Indonesia and the Andaman Islands, north to Burma, Thailand, Vietnam and Mindanao in the Philippines, while D. brachiata (Hook. & Wils.) Vitt comb. nova is restricted to the island of Luzon in the Philippines. The evolution and dispersal of this genus can be related to the northward movement of Gondwanan island blocks during the Cretaceous.

This catalogue provides an annotated listing of the mosses (MUSCI) reported from the Guianas (Guyana, Surinam, French Guiana), based on work on the Moss Flora of Suriname, which is now nearing completion. In total 238 species in 90 genera are listed. A list of synonyms (including 10 new ones) and a systematic arrangement of the genera and families are also provided. The following new combinations are proposed: Callicostella guatemalensis (Bartr.), Sematophyllum lonchophyllum (Mont.), Sematophyllum pacimoniense (Mitt.) and Trichosteleum intricatum (Th?r.).

Crossomitrium is a genus of neotropical, essentially epiphyllous mosses. The genus consists of six species that are distributed in two sections: section Crossomitrium (C. acuminatum, C. patrisiae, and C. scabrisetum) and section Cormophila (C. epiphyllum, C. saprophilum, and C. sintenisii). Section Crossomitrium is characterized by 1. plants nearly always on leaves or twigs, 2. lateral leaves oblongacuminate and widest below the middle, 3. leaves when dry that arch from an erect base downward to the substrate and, 4. the presence of specialized brood branches that are closely adnate to the substrate and have tightly imbricate leaves. Section Cormophila is characterized by 1. plants growing on rocks and tree trunks as well as on leaves, 2. lateral leaves oval to obovate, acute to apiculate and widest above the middle, 3. leaves when dry flattened to the substrate and, 4. the presence of erect, specialized brood branches that have leaves spreading on all sides. Crossomitrium is placed in the Hookeriaceae (sensu Whittemore & Allen, 1989) on the basis of its branched stems, ecostate leaves, straight, unbranched rhizoids that are tightly clustered just posterior to the leaf bases, 2-celled axillary hairs and weakly pigmented stem cortex. Within the Hookeriaceae Crossomitrium is considered close to the genus Lepidopilum by virtue of 1. its peristome which is hydrocastique and has a high basal membrane, 2. the spinose setae of C.acuminatum and C. scabrisetum, 3. the irregular subdivision of its stomatal guard cells (including the presence of stomates at the base of raised pustules), 4. leaves doubly serrulate by the projecting ends of contiguous marginal cells, 6. absence of a stem central strand. It differs from Lepidopilum in its 1. symmetric, ecostate leaves, 2. calyptra fimbriate by downward projecting, multicellular hairs that arise from the margins of the calyptra, 3. collenchymatous exothecial cells, 4. the presence of broodbodies on specialized brood branches as well as in clusters just below the junction of the leaf with the stem.

The distinctions between dispersal and vicariance are discussed and shown how they relate to geological history. Postulated theories on the tectonic origins and history of the Greater Antilles are reviewed, as well as possible climatic events that would affect biogeography. Numerous zoological examples are presented to argue both dispersalist and vicariance viewpoints. It is proposed that the modern moss flora of the Greater Antilles is best explained primarily by dispersal events. Post-vicariant events, such as Pleistocene climate changes, would have extirpated the vast majority of mosses from the islands and even among those taxa that survived, disperal by the same taxa would have obscured their origins. It is assumed that many of the North American elements in the high elevations of Hispaniola are a result of invasions during the Pleistocene. The Andean elements are considered relatively recent dispersally derived taxa that have successfully colonized the Antilles because of ecologically compatible habitats.

After some 150 years of research there are more than 575 publications on Mexican bryophytes. Most of these appeared in the last two decades; it is suggested that research toward the preparation of the Manual of Mexican mosses increased the rate publication for that period of time.

The growth habit of the Hedwigiaceae has been described variously as acrocarpous, pseudopleurocarpous, or pleurocarpous. Anatomical evidence presented here indicates that Hedwigia ciliata is acrocarpous. The archegonia are terminal on the main shoot, and the branching pattern is sympodial. The main axis of each plant thus consists of a succession of subterminal innovations, rather than a single shoot of indeterminate growth. Since the plants are plagiotropic and are pleurocarpous in appearance, this growth pattern can be also called pseudo-pleurocarpous.

The study is based on the major part of the bryophyte material collected during the Koponen-Norris expedition on the Huon Peninsula, Papua New Guinea, in 1981. Only taxa which were collected at least twice are included. Five altitudinal zones, the boundaries of which are indicated by discontinuities in the bryophyte flora, are distinguished: 0 - 300 m, 300 - 1200 m, 1200 - 2200(-2300) m, 2200(-2300) - 2800(- 2900) m, and 2800(-2900) -3400 m. These zones, each characterized by a typical species assemblage, are well in accordance with some earlier New Guinean zonation schemes based on the phanerogamic flora and vegetation. The most obvious correlations between bryophytes’ altitudinal ranges on the Huon Peninsula and their general phytogeography are: New Guinean or Western Melanesian endemics, as well as Malesian endemics, are concentrated at relatively high altitudes (zones III-V); Asian - Oceanian and Asian - Oceanian - Australian taxa, notably mosses, are relatively strongly represented at low to moderate altitudes (zones I-III); species which have their main distribution in the northern hemisphere occur at high altitudes; 'cosmopolitan' species either have wide vertical ranges or are restricted to high altitudes.

Campylopus with nearly 200 revised species is one of the largest genera of mosses in the world and has extremely broad geographical, altitudinal and ecological ranges. Factors to be considered for the rich speciation are 1) the enormous anatomical plasticity of the structure of the costa, 2) the ability for vegetative propagation utilizing different methods, and 3) the special twist mechanism of the cygneous setae. Phytogeographical interpretations of present ranges of species of Campylopus lead to the conclusion that this genus is of Gondwanalandic origin. Most of the species seem to be cool temperate in origin. They have adapted to dry habitats in the Mesozoic and invaded the tropical mountains during the Tertiary, accompanied by rich speciation. This is supported by the physiology of these species. According to preliminary gas exchange measurements, tropical montane species do not differ from temperate species, and are not able to stand climatic conditions of the tropical lowland rainforests; a relatively young habitat for bryophytes. A cladistic analysis of the infrageneric categories of Campylopus using phytogeographical evaluations of apomorphic character states shows that the section Homalocarpus seems to be the most primitive and the subgenera Campylopidulum and Thysanomitrion the most derived.

The Frullania taxa on Mount Albert Edward, Papua New Guinea, form many associations that suggest a high degree of niche similarity, but at different altitudes, different associations form. The species diversity of the genus is greatest at the middle altitudes and least in the dry lowlands. This altitudinal separation is apparent in the niche widths of the taxa. The members of the four sibling taxa pairs examined exhibit distinct altitudinal niches, suggesting that the sibling taxa are distinct, with different niche optima.

The Guianas (French Guiana, Suriname, Guyana) are probably one of the last areas of the world covered largely by virgin lowland rain forest. Species diversity of epiphytic bryophytes was investigated in dry evergreen forest and mixed forest using mountaineering techniques to ascend into the canopy. The results indicate that the lowland rain forest is richer in species than previously believed due to neglect of the canopy flora, which may hold more than 50% of the local species. The mixed forest holds the richest flora and on one single forest tree up to 67 bryophyte species were found (50 on average); 28 trees yielded 154 species. A species/area curve indicates that epiphytic bryophyte species are usually commonly distributed in the forest and a few trees may yield much of the local flora. A recent checklist of the Guianas includes over 600 species of bryophytes: 375 Hepaticae and 234 Musci. As the region lacks in altitude (except on Mt. Roraima) the general character of the bryophyte flora of the Guianas is typically lowland neotropical. Over 80% of the species are rather widespread in tropical America (Amazonian species included), and the remaining are Guayana Highlands, northern Amazonian or Caribbean elements. Endemism is very low: 2.5 %.

The South American paramos appeared in Pliocene times and persist to the present day. The moss flora of this habitat consists of an estimated 400 species that comprise 8 floristic groups. In Venezuela these groups and their percent representation are as follows: neotropical 37%, Andean 26%, cosmopolitan 18%, Andean-African 8%, neotropical-Asiatic 3%, neotropical-Australasian 2%, temperate Southern Hemisphere 2% and northern boreal-temperate 2%. Acrocarpous taxa outnumber pleurocarps by nearly 3:1. The neotropical and Andean floristic stocks likely were present prior to late Pliocene orogenies that elevated the cordillera above climatic timberlines. These species may have existed in open, marshy areas (paramillos) or may have evolved from cloud forest ancestors. Taxa of northern boreal- temperate affinities, including those with Asiatic distributions, probably arrived in the paramos during the Pleistocene, a period which may also have seen the establishment in the Northern Andes of some cosmopolitan elements. Species with temperate Southern Hemisphere and Australasian affinities likely spread first to austral South America thence migrated northward during a cool, moist interval sometime over the past 2.5-3 million years or may have become established in the paramos as a result of long- distance dispersal.

A project dealing with the hepatic and moss floras of New Guinea and the Solomon Islands has proceeded more than halfway. The revision of the flora is based on the study of ca 17000 specimens collected in 1981. Two new genera and ca 50 new species have been described in 33 published papers and seven manuscripts. Many families, genera and species not previously recorded for the area have been added to the flora. More than 300 names have been reduced to synonyms. The percentage of endemic species of liverworts (40 %) is higher than that of mosses (18 %). Most of the endemic species occur at elevations above 1700 m. The geological history of New Guinea suggests that these high altitude endemics may be relatively young, i.e. less than 10 million years old. The moss flora is more closely related to the floras of Indonesia and the Philippines and continental Asia than to that of Australia. This can be explained by plate tectonics. The altitudinal distribution of hepatic and moss floras partly coincides with the zonation of vegetation proposed earlier. Human influence on bryophyte floras is devastating but a part of the flora may survive in gardens and plantations.

A review of the status of bryological research in each of the nations, states or governmental units of southern Melanesia, Micronesia and tropical Polynesia shows the imperfect state of knowledge about the Pacific tropical islands. Best known overall are Hawaii and Micronesia with Wallis and Futuna, the Marquesas and the high mountains of Fiji seeming to be the least known potentially species rich areas. Involvement of residents from Pacific islands in botanical study and preservation of ecosystems should be encouraged by tropical bryologists.

During the past 5 years intensive bryological explorations were carried out in Tanzania with special emphasize on hitherto undercollected areas (e.g. Nguru mountains, Mafia Island, unknown accesses of Mount Kilimanjaro and Meru) and on special habitats (e.g. rocky semi-desert or heath vegetation and alkaline tolerant epiphytic vegetation along the Rift Valley). These collections (above 8000 numbers) resulted in numerous records, some of them new to the African continent and at least 8 species new to science. The data point to interesting phytogeographical links and help to explain the evolution of the flora of East African volcanoes and crystalline mountains. Hitherto unknown oil bodies of more than 50 liverwort species were investigated. This paper does not give a full account of these studies but only provides examples to illustrate the above points.

The land areas of the Western Hemisphere south of the United States support over 276 species of Fissidens (Wijk et al. 1962, 1969). This number is approximately 30% of the total number of species known. Progress made on a monograph of the family in the neotropics and the adjacent areas is summarized; approximately 50% of the species have been studied. Commonality among the neotropical, African and Asian species of Fissidens is discussed. Changes to be made in the classification of the family are indicated. New characters used in distinguishing species and the classification of the family are enumerated.

Recent conclusions on the limits of the Leucobryaceae and on the function of the Leucobryaceous leaf are used as basis for further observations on evolution of the group. Eight genera are recognized in the family; 1. Leucobryum, 2. Steyermarkiella, 3. Ochrobryum, 4. Arthrocormus, 5. Schistomitrium, 6. Holomitriopsis, 7. Cladopodanthus, and 8. Octoblepharum. The leaf form, capsule shape, and peristome substructure of Leucobryum seems to derive from a Campylopus-type member of the Dicranaceae. Four basic stages are noted in the functional evolution of the family. 1. The stratification of the leaf into leucocysts and chlorocyst layers with leucocysts holding water and internally generated gas; 2. The shift from soil substrates seen mostly in Temperate Zone Leucobryum to rotten wood substrates or epiphytism; 3. Increasing reliance on vegetative reproduction with reduction of reliance on sporophytes; 4. Morphogenetic increase of the number of chlorocysts in the leaf. Geographical concentrations of the genera are noted, and distributions between hemispheres are apparently mostly by way of the South Atlantic. The use of functional considerations in evolutionary studies is emphasized. The retention of paraphyletic groups in taxonomy is defended.

The neotropical hepatic flora, predominantly constituted by members of the Jungermanniales and Metzgeriales, includes a disproportionate number of genera which are endemic (over 38) and a number which evidently originated here but have shown slight and in a geological sense, modern dispersal by solitary species. Endemism is confined almost to the Jungermanniales; it is to a large degree of a unique sort: confined to highly apomorphic derivatives, often extremely reduced, sometimes confervoid or thalloid (aside from 'normal' sexual branches). These endemics are derivatives of basically cool-Gondwanalandic suborders, chiefly Lepidoziineae and Cephaloziineae which, in the Antipodes today include a wide range of plesiomorphic taxa. The highest proportion of endemic genera, often stenotypic (1-3 species each) occurs in the upper montane zone: from upper Andean forest to páramo, to the edge of permanent snow and ice; a smaller number occurs at upper elevations of the Guyana Shield, but more occur in the riverine systems that dissect this shield. The taxa found there (i.a., Zoopsidella, Pteropsiella, Schusterolejeunea, Cephalantholejeunea) are among the most apomorphic of all hepatics. The amount of endemism is shown to be higher than in any comparable region of the globe. It is assumed that this is owing to: (a) isolation, exceeding 40 m.y. and probably exceeding 60 m.y.; (b) continuous tectonic activity, preserving the 'raw' and 'pioneer' habitats which are necessary for the survival of 'fugitive', 'shuttle' and other types of pioneer taxa; (c) the antiquity of the Guyana Shield and its riverine system; (d) creation of striking ecological gradients, many biotic islands; (e) fluctuation in extent and degree of isolation of these 'islands', leading to (f) rapid evolution due to genetic drift and perhaps enhanced selection pressures. It is concluded that part of the complexity of the flora is due to preservation of some elements on the old Guyana Shield but most is due to relatively rapid evolution during Tertiary times. A final contributing element has been the fact that movement of the South American plate has been primarily from east to west, so that the relevant land area has not been rafted into regions with very different climatic parameters: the degree of extinction seen in, e.g., India and Australia is not evident here. It is concluded that the amount of endemism seen, and its extreme kinds, 'need' in excess of the 40-60 m.y. time span which seems available. In particular, the large number of high elevation endemics, some (such as Ruizanthus) very isolated, cannot be satisfactorily explained by assuming their evolution in the few million years available since alpine regions were created by the rise of the Andes. It is almost necessary to conclude that limited 'pre-Andes' must have existed and that the ancestors of the isolated taxa seen today in alpine loci in Colombia and Venezuela originated elsewhere. The other side of the outlined scenario is that with the near-total isolation of tropical America until the Andes were elevated, and until the Pliocene connection to North America arose, one would expect to see few and scattered intruders from cool-Gondwanalandic areas and from Laurasia. The modern flora reflects exactly this.

The generic and specific affinities of the Philippine, Bornean and New Guinean hepatic floras were analyzed by calculating the Kroeber's percentage of similarity on the basis of recently published checklists. It is observed that the overall affinities parallel that exhibited by local moss floras except for one important difference. For the three areas, the number and distribution of species of large, actively evolving hepatic genera are noted to be disparate and with few shared taxa. Contrastingly, the large and actively evolving moss genera produce consistently large number of species in all three areas with an equally large number of shared taxa. The strong dependence of many hepatic taxa on asexual reproduction and the poor spore dispersability are accepted as the best explanation to this phenomenon.

As currently understood, the Lejeuneaceae flora of Australia consists of 122 species in 27 genera. The family occurs almost exclusively in rainforested areas along the eastern coast of the continent. Based on species composition, three floristic regions are recognized: tropical, subtropical and temperate. The tropical region contains 80 percent of the total number of Lejeuneaceae found in Australia, the subtropical region contains 45 percent, and the temperate region only 15 percent of the total flora. The affinities of the Lejeuneaceae in the tropical and subtropical regions are strongest with the Asian flora, and those of the temperate region are strongest with the New Zealand flora. The diversity of the Lejeuneaceae flora in Australia is higher than might be expected for a non-equatorial region. This diversity may result from the wide variety of rainforest habitats that are available along both latitudinal and altitudinal gradients. The temperate flora is probably derived from that which existed in Australia, New Zealand, Antarctica and probably southern South America prior to the breakup of Gondwanaland. The modern tropical flora is probably a mixture of species that were part of the original northern Gondwanan flora and those that have invaded more recently.

The concept of Bryohumbertia walkeri (Mitt.) J.-P. Frahm was based on isotype specimens, which are, however, not identical with the holotype which consists of Campylopus comosus (Reinw. & Hornch.) Bosch & Lac.Therefore the next older epithet avilable must be chosen for B. walkeeri and the newcombination B. subcomosa is introduced accordingly.

All the species of Chorisodontium record fromthe neotropical mountains (Bolivia-Costa Rica) have been critically recived. Three species, C. nigricans Herz., C. mittenii (C. Muell.) Broth. and C. wallisii (C. Muell.) Broth. are accepted. Chorisodontium speciosum (Hook. f. & Wils.) Broth. is placed as variety to C. wallisii.

A bryological inventory of the Upper Mazaruni District, Guyana (former British Guiana) yielded almost three hundred species, including 2 genera and 11 species new to science and 130 species new to the Guianas. The densely forested and very humid north slope of Mount Roraima (500-2300 m.) proved to be the richest area for bryophytes and most of the novelties were found there. The present paper provides an enumeration of the species collected with a brief characterization of their habitat. The following species are described as new: Haesselia acuminata Gradst., Plagiochila gymnocalyx Inoue, Radula gradsteinii Yamada, Radula guyanensis Yamada, Radula mazarunensis Yamada and Stenorrhipis grollei Gradst. Anastrophyllum subg. Vanaea Inoue & Gradst. from Mount Roraima is elevated to generic rank.

37 species of mosses are reported from the Mascarenes. Of these 19 belong to the genus Campylopus and 8 to Leucoloma. Three are new to the Mascarenes i.e. Campylopus leucochlorus (C.M?ll.) Par., C. paludicola Broth. and C. subperichaetialis Biz. & Kilb., two are new to Mauritius i.e. Bryum truncorum (Brid.) Brid. and Leucoloma cinclidotioides Besch. and four are new to R?union i.e. Campylopus incacorralis Herz. C. praetermissus J.-P. Frahm, C. trachyblepharon (C. M?ll.) Mitt. ssp. comatus (Ren. & Card.) J.- P. Frahm and Leucoloma rutenbergii (Geh.) Wright var. elatum Ren. The variety is new to the Mascarenes.

There are 26 species of Campylopus in Central America. They are divided into three groups on the basis of two characters: the presence or absence in the costa of a ventral layer of enlarged, hyaline cells and the presence or absence in the stem of an outer hylodermis. Dicranum costaricensis Bartr. is transferred to Campylopus as C. valerioi nom. nov. Campylopus hoffmanii and C. standleyi are recognized as distinct species. Six new synonyms are proposed: C. straminifolius = C. densicoma; C. costaricensis = C. surinamensis; C. roellii = C. tallulensis; C. donnellii = C. zygodonticarpus; C. tuerckheimii = C. zygodonticarpus; C. sargii = C. zygodonticarpus.

A revised moss checklist for Colombia recognizes 877 species distributed among 242 genera and 65 families. Departmental distribution is provided for all species. This paper is based on the previous checklist by Florsch?tz-de Waard & Florsch?tz (1979), publications since that time, on the extensive holdings of the New York Botanical Garden, the Institute of Systematic Botany, Utrecht, and other herbaria, and on recent field work. Included in this list are a number of the collections made by Aguirre C., Cleef, Griffin, Killip, Schultes, Steere, van der Hammen and van Reenen, among others, which have not previously been incorporated into the Colombian moss literature. Comparison of the number of species reported for each of the departments based on the 1979 and the present checklist both suggest that over half of the departments are poorly known. Forty new additions to Colombia are provided in this catalogue: Amblystegium serpens, Anoectangium aestivum, Astomiopsis amblycalyx, Breutelia brevifolia, Brymela parkeriana, Bryohaplocladium praelongum, Bryum coloratum, B. perlimbatum, Chorisodontium setaceum, Dicranum peruvianum, Drepanocladus uncinatus, Encalypta asperifolia, Entodon hampeanus, Epipterygium immarginatum, Fissidens allionii, F. diplodus, F. intermedius, Groutiella obtusa, Gymnostomum recurvirostrum, Hymenodon reggaeus, Leiomela ecuadorensis, Lepidopilum affine, L. cuspidans, L. cubense, Leptodontium stellaticuspis, Leskea plumaria, Leskeadelphus bolivianus, Neckera urnigera, Potamium deceptivum, P. pacimonense, Pseudotaxiphyllum distichaceum, Rhegmatodon polycarpa, Schistidium apocarpum, S. rivulare ssp. latifolium, Scorpidium scorpioides, Syrrhopodon steyermarkii, Tortula caroliniana, Zygodon ehrenbergii, Z. fragilis, Z. stenocarpus. Approximately 560 new departmental records are included. Several new combinations are made: Calyptrochaeta deflexa (C. Muell.) comb. nov., C. nutans (Hampe) comb. nov., Pleuridium subenervis (Hampe) comb. nov., Rhodobryum perspinidens (Broth.) comb. nov., R. roseodens (C. Muell.) comb. nov., Schizymenium brevicaulis (Hornsch.) comb. nov., S. dolichothecum (Herz.) comb. nov., S. pectinatum (C. Muell.) comb. nov., S. subobliquum (Hampe) comb. nov., Sematophyllum sticticola (C. Muell.) comb. nov. and, S. turgidulum (Herz.) comb. nov. Several further species are reduced to synonymy: Aulacomnium venezuelanum Mitt. (=A. palustre), Grimmia bogotense (Hampe) Jaeg. (=G. longirostris), Mielichhoferia elegans Herz. (=Schizymenium bogotense), Pohlia integridens (C. Muell.) Broth. (=P. elongata), and P. paucifolia (Jaeg.) Broth. (=P. elongata)