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91 Tropical Bryology 2: 91- 101, 1990

Campylopus, a modern and successful genus !?

Jan-Peter Frahm Universität Duisburg, Fachbereich 6, Botanik, Postfach 101503, 4100 Duisburg, W-Germany

Abstract. 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.

1. Introduction given in textbooks, but probably no more The somewhat provocative title goes back than 10.000 (4.000 species of hepatics to Schuster (1984), who (as a and 6.000 species of mosses). There are hepaticologist) interpreted some only a few genera of mosses with numbers distribution maps of Campylopus and of species comparable to Campylopus, called this genus ‘modern and successful’. but these have not yet been revised critically So it would be interesting to prove whether on a worldwide basis, and therefore a moss genus such as Campylopus is Campylopus may be one of the largest really modern and successful. genera of mosses in the world. Based on In total, more than 1000 species of an estimated total of about 6000 species of Campylopus have been described. Twenty mosses, i of every 30. mosses (or 3.3% of years ago, Index Muscorum (Wijk et al. all mosses) belong to the genus 1959) listed more than 700 legitimate Campylopus. species. Since that time, the number has The genus Campylopus has a wide been reduced by worldwide revisions to latitudinal range between 650N (Alaska) less than 200. This is a common effect in and and 650S (South Sandwich Islands) bryophytes, especially in tropical ones, and an enormous altitudinal range between where rates of reduction owing to sealevel and more than 4500 m elevation. worldwide revisions, are about 60-70%. The species occur on a variety of different This indicates that there are not 25.000 substrates such as nutrient poor sand, humic species of bryophytes in the world as soil, peat, rocks, rotten and living wood,

93 2.1 Gametophyte seems to function only in wet habitats, 2.1.1 Costa since the cell walls of large hyalocysts are very delicate and can probably not stand The most conspicuous vegetative character desiccation. In species pairs the species of of the genus Campylopus is the broad wet habitats have larger hyalocysts than costa with extreme diversity of internal species in drier habitats, as exemplified by differentiation. There is no comparable Campylopus shawii Wils. growing in range of variation in the structure of the swamps and C. setifolius Wils. growing costa in any other moss genus. All the on wet cliffs (Frahm 1985). It seems, different expressions between types with however, to be paradox that species of wet two stereid bands and a median deuter habitats should depend on storing water, band (as commonly found in the Dicrana- where there is no dry daily or annual ceae and also other families) and costae season. Thus it may be that the function of with no stereids at all can be explained by the hyalocysts (as well in the Leucobrya- a few cell divisions (fig. 1). Thus the ceae) have been misinterpretated. As Ro- mechanism behind this broad variety of binson (1985) has observed, the hyalocysts structures is relatively simple. in the Leucobryaceae often show air What are the advantages of these different bubbles, and the major function may not costal structures? be water storage but gas exchange. This a. mechanical stability. Stereids with firm hypothesis is supported by the location of thickened walls, provide mechanical the chlorocysts, which are situated in the support either in layers on the adaxial middle of the leaf without any direct contact surface or in bundles in the abaxial part of to the atmosphere. the costa. They are supposed to be good Another method of water storage is protection against shrinking caused by between the dorsal lamellae of the costa. desiccation and are therefore are found In species pairs, the species of drier habitats frequently in dry adapted species. In have the longer lamellae, for example species pairs (often sympatric species Campylopus pilifer Brid. and C. introflexus differing mainly in one character of the (Hedw.) Brid. (Frahm 1985). costa and the habitat), the species of the d. Water conducting is probably possible wetter habitat has ventral hyalocysts, not only from cell to cell or through the whereas that of the drier habitat has ventral pectine lamellae of the walls but also more stereids. One of many examples is efficiently through bundles of stereids. In Campylopus comosus (Reinw. & some species the alar cells (functioning for Hornsch.) Bosch & Lac. growing on soil, water uptake from the water conducted with small ventral hyalocysts and C. along the stem) bulge into the costa, flagelliferus (C. Müll.) Jaeg. growing in indicating a conducting pathway from the the same range but epiphytic with ventral alar cells to the costa. stereids (Frahm 1985, Frahm et al. 1985) e. Gas exchange combined with photo- b. Photosynthesis. Assimilation is carried synthesis. Effective gas exchange requires out by a median band (the so called deuter a large surface. Lamellae (being cells) and a dorsal band of chlorocysts. chlorocysts) seem to function not only for Since the width of the costa is usually water storage but also for gas exchange as more than half of the leaf width, and the shown by Campylopus pilifer Brid. var. basal laminal cells are often lamellatus (Mont.) Gradstein & Sipman, nonchlorophyllose, the costa is the main which is not found in arid environments source for photosynthesis. like C. pilifer s.str. but in rainforests. In c. Water uptake and storage. Water is this kind of habitat, water storage is not easily taken up and stored by hyalocysts, required, but gas exchange in high especially the large ventral ones. This humidity may be a problem. 94 Thus the plasticity of different structures Campylopodiella (but not in other closely of the costa allows adaptations to a broad related genera such as Atractylocarpus or variety of habitats. The facility to modify Pilopogon). such structures has promoted the broad The sigmoid curve in the seta is caused by ecological and geographical ranges and its development (Frey & Frahm 1987 figs. enhanced the high number of species. 1-7). When the seta has reached half of its final length, it curves down, the capsule 2.1.2 Vegetative propagation developes, often leaves the calyptra between the perichaetial leaves and curves Compared with other genera of mosses, up again. vegetative propagation is relatively In this way the young sporophyte important in Campylopus. In this genus, developes protected in the perichaetial all different kinds of vegetative propagation leaves which is an advantage, especially from microphyllous branches and in exposed or dry habitats. deciduous leaves to special brood leaves, The twist mechanism of the seta causes broken leaves and stem tips are found. If wide movements of the capsule in a 40% of all species are known only sterile, moistened state at the same time as when the importance of vegetative propagation the peristome is open. The function of is evident. The vegetative propagation these circular movements of the capsule is allows a species to survive in a habitat as not clear. It may enhance spore dispersal a unisexual clone. It also allows clones to to all directions, but this is a relatively survive long unfavourate climatic small advantage compared with the conditions with no sexual reproduction. anatomical structures necessary for these At least it allows propagation over short movements. Spore dispersal in wet weather distances until clones of different sexes conditions also prohibits long distance meet and allow fertilization. Apparently dispersal. However, since Campylopus as most of the species (if not all) are able to many other genera of Dicranaceae are vegetative propagate by more than one dioicous, male and female spores need to kind of vegetative propagation. land near to one another in order to establish new male and female clones which are 2.1.3 Perichaetia situated close enough to allow fertilisation. The mechanism for these uncoiling Differentiated bud-like perichaetia function movements have not been known yet but for splash cup dispersal of spermatozoids could be explained by a study of the and also as protection for the young ultrastructure of the setae (Frey & Frahm sporophyte during the stage of 1987). The epidermal cell layer of the development when the seta is curved into setae possesses a three layered wall with the perichaetial leaves. Such perichaetia asymmetric lumens. SEM and TEM are found in all infrageneric categories of studies revealed a distinct lamination in Campylopus. the second layer and small pores in the outer, asymmetrically thickened epidermal 2.2 Sporophyte cell layer of the seta, and a firm inner teriary cell wall. In dry state the setae are The major characteristic of this genus is coiled by spirally arranged microfibrils in the seta which is curved sigmoid in the the secondary cell wall. Water (or water middle and twisted in the upper and lower vapour) is taken up through the outer cell part and uncoils when moistened. This wall, stored between the microfibrils of character which is also present in genera the secondary wall, causing elongation of such as Microcampylopus, the setae and uncoiling movements. Campylopodium, Dicranodontium or Opposite twist directions in the upper and 95 lower part of the setae prevent the setae ciation: from being twisted off. 1. adaptations to dry habitats. For example, Campylopus introflexus (Hedw.) Brid. can be regarded as the ancestor of C. pilifer 3. Distribution and Speciation Brid., adapting to dry habitats by longer costal lamellae for storing water. Both Campylopus is an ideal genus for phyto- species show a gondwanalandic range: C. geographic interpretations because of its introflexus along the south coast (today wide distribution, broad ecological range, circumsubantarctic), C. pilifer in the wide altitudinal range and high number of interior (today from South America to species. Insofar it is equivalent to several India). By the same way, C. julaceus Jaeg. other genera or even one or more smaller (with one subspecies in SE-Brazil and one families. in E-Africa) and C. aemulans (Hampe) The worldwide distribution of the genus is Jaeg. (in SE-Brazil) can be derived. uneven on both sides of the equator. There Campylopus surinamensis C. Muell., a are 14 species in the subantarctic but only neotropic savannah species, is derived 1 species in the subarctic (Frahm 1988). In from the subantarctic C. vesticaulis Mitt. the tropics, the species of Campylopus are 2. Adaptations to alpine habitats. There mostly confined to the montane belt. There seem to be two pathways to alpine habitats, are only a few species occurring in the one from the subantarctic, especially lowlands, mainly in savannahs and not in through the Andes, which is well known lowland rainforests. The species in the for many other tropical alpine bryophytes, temperate belt of the northern hemisphere and another one from montane species. are (1) either mainly tropical montane There are several pairs of species or species occurring as remnants of the subspecies, one of them confined to Tropical Tertiary flora in oceanic regions montane, the other to alpine habitats. (cf. many species of North America and Examples are C. albidovirens Herz. in Europe, Frahm 1980, 1984), or (2) are of subalpine forests of the Andes and C. subantarctic origin and probably pittieri Wils. in the Paramos; C. flexuosus introduced into the northern hemisphere (Hedw.) Brid. ssp. flexuosus in the montane (cf. Campylopus introflexus (Hedw.) Brid. regions and ssp. incacorralis (Herz.) J.-P. in North America and Europe, Frahm Frahm in the subalpine regions of the 1980, or C. pyriformis (Schultz) Brid. in Neotropics and Africa, C. cuspidatus Europe, cf. Corley & Frahm 1982), or (3) (Hornsch.) Mitt. var. cuspidatus in are endemics related to sister species of montane rainforests of the Neotropics and tropical areas (cf. Campylopus setifolius var. dicnemioides (C. Müll.) J.-P. Frahm Wils. derived from C. shawii Wils., Frahm in the alpine. Other examples are C. 1985a). This leads to the suspicion that the amboroensis Thér. in the high Andes and genus may have its origin on the southern C. johannis-meyeri (C. Müll.) Kindb. in coast of Gondwanaland and has spread to the afroalpine mountains, both derived the tropics. This pathway is illustrated by from C. pilifer Brid. The origin of the several subantarctic species, which have alpine taxa may be explained as ecological closely related species in the tropics, adaptations, which may have been sometimes 3 such species derived from supported by extensions of the alpine belt the same (still present) ancestor in South during the fluctuations of vegetation belts America, Africa and Australia (Frahm in the Quaternary. 1988), representing a species group with a Interestingly, one new habitat like the species mosaic of several small, mostly páramo has been colonized by different allopatric but also sympatric species. taxa from different relationships within There are apparently several ways of spe- the genus, resulting in very similar 96 adaptations. For instance, Campylopus Wils. in the British Isles by changing pittieri Williams and C. cavifolius Mitt. habitats from swamps to wet rocks. both grow often intermixed and can hardly be distinguished in the field. Only transverse sections of the costa show that 4. Physiology these two species belong to different systematic groups. There are similar The cool-temperate origin of the species analogous developments in Dicranum. of Campylopus as that of many bryophytes Species adapted to alpine habitats show (Schuster 1984) and probably most tropical the same growth form (compact cushions, montane mosses is supported by their orthophyllous appressed leaves, subtubular physiology. These species lack the ability leaf apices). They show, however, to descend to the tropical lowlands, as significant differences in the structure of measurements of the gas exchange have the costa and the shape of the capsules (for shown (Frahm 1987, 1987a), due to high example D. groenlandicum Brid. with rates of respiration. Physiologically seen erect capsules and two stereid bands, D. tropical montane bryophytes react as do brevifolium (Lindb.) Lindb. with curved cool-temperate species. Only a few species capsules and two stereid bands, and D. were able to adapt to the humid tropical muehlenbeckii B.S.G. with curved lowlands, probably the youngest in capsules and two stereid bands and two evolution. In Campylopus, there are no epidermal layers). This demonstrates that lowland rainforest species, and only a few species from different evolutionary lines lowland savannah ones. The majority are have adapted to similar habitats. montane in distribution. Tests in climate The only species of Campylopus occurring chambers show that species such as in the subarctic and alpine regions of the Campylopus flexuosus cannot stand the northern hemisphere , C. schimperi Milde, ecological conditions of tropical lowland surprisingly shows the closest affinities to forests characterized by high temperatures subantarctic species. It is, however, not and low light intensities. found in the Andes of South America or the African mountains. This may be an 5. Cladistics example for a species which has drifted from the southern hemisphere to Asia via A cladistic analysis could give an idea, the Indian subcontinent and has spread which species posses the most primitive through the northern hemisphere. This characters and which have the most pathway has been pointed out by Schuster advanced features in this genus. This could (1972, 1976) for hepatics, Smith (1972) also provide a hypothetical background of for Polytrichaceae, and Raven & Axelrod the origin of this genus. It requires, however, (1974) for Angiosperms. the evaluation of primitive and derived 3. Adaptations to different habitats: This characters. This is a major problem in this concerns sympatric species which occurin genus because of the enormous variation different habitats, especially epiphytic of characters. For example, the capsules species, that are derived from terrestrial may be asymmetric or symmetric, the ones. Examples are C. comosus (Reinw. calyptras ciliate or nonciliate, the basal & Hornsch.) Bosch & Lac. and C. laminal cells hyaline and thin-walled or flagelliferus (C. Müll.) Jaeg. in SE-Asia, incrassate and pitted. or C. lamellinervis (C.Müll.) Mitt. and C. There is some support for the evaluation huallagensis Broth. in South America, the of morphological character states by the latter species being epiphytes. By the same interpretation of ecological, differentiation, Campylopus setifolius phytogeographical phytochemical, Wils. seems to have split from C. shawii developmental and palaeobotanical facts.

98 It is in ecological evidence that epiphytic Paraleucobryum enerve. Stereids are species (found only rarely in this genus) produced in later stages of development show apomorphous character states such by cell divisions of hyalocysts. In contrast, as incrassate laminal cells and stereids in in young leaves of Dicranum spadiceum transverse section of the costa. These are Zett., the median deuter cells produce the same adaptions as found in dry adapted abaxial and adaxial stereids (fig. 2b). The soil species. ontogenesis of stereids in Campylopus There is phytogeographical evidence that seems therefore to be different from that in the subgenus Thysanomitrion has most of Dicranum. its representatives in SE Asia but only one There might also be palaeontological in the subantarctic, which is the probable evidence for the fact that hyalocysts in the ancestor and its character states can be costae are a plesiomorphous character regarded as plesiomorphous. state. Smoot & Taylor (1986) described a There are only a few phytochemical data moss from silicified peat of the late Permian present for this genus (Frahm 1983). These of the Antarctic that possessed a data show that certain species in the section multilayered costa. The areolation (figs. Homalocarpus have no flavonoids 11-13) is quite similar to present species of whereas the highest diversity is found in Dicranum. One transverse section (fig. 2) the subgenus Thysanomitrion. resembles much the structure of a species A major problem is in the interpretation of of Campylopus with a median row of the costal anatomy. Are transverse sections deuter cells, ventral hyalocysts and smaller without stereids and large hyalocysts or dorsal, nonstereidal cells. The other those with ventral and dorsal stereids plei- transverse section (fig.5), which I would siomorphe? Within the Dicranaceae, the not refer to the same species, shows ventral most common type of costa is that with and dorsal hyalocysts with two median ventral and dorsal stereid bands. Therefore clusters of stereids similar to costa in present for genera such as Dicranum, species species of Brothera or Campylopodiella. with tendencies to larger cells instead of Therefore multilayered costae with hyalo- stereids are regarded as derived (Peterson cysts were already present in the Late 1979). However, this seems not to be the Palaeozoic. fact in Campylopus. As shown for the In conclusion, costae with hyalocysts, erect epiphytic species and species of the capsules, a dicranoid peristome with subgenus Thysanomitrion, these supposed elongate triangular striate teeth split young species have bands of stereids. So halfway are regarded as plesiomorphic. the genus Campylopus may be derived To the contrary, costae with double stereid from a dicranoid ancestor by evolving bands, asymmetric capsules or filiform hyalocysts (as it might have been the same peristome teeth are regarded as with the genera of Paraleucobryaceae), apomorphic. but within Campylopus there seems to be For the cladistic analysis, the infrageneric support for the opposite evolution, that is categories (subgenus Thysanomitrion, reducing the hyalocysts. subg. Campylopus with sections Transverse sections of the leaf tips of the Campylopus and Homalocarpus) as youngest leaves in Campylopus flexuosus proposed by Frahm (1983) have been show that the apical cell developes into the used along with the subgenus Campylopi- median chlorophyllose deuter band. The dulum described later by Vital (1984). deuter cells produce abaxial and adaxial The analysis using Henningian cladistics hyalocysts (fig. 2a). By this way the (fig. 3) shows that the subgenera transverse section in an early stage of Campylopidulum and Thysanomitrion development of a Campylopus leaf re- have the highest number of apomorphous sembles that of a mature leaf of character states, whereas the subgenus 99 Campylopus is the most primitive one in were present and whether they were which the sect. Homalocarpus turns out continous (allowing migration) or to have the most plesiomorphic characters. separated by arid regions. An interpretation This does not automatically include any of geological sediments allows such conclusion about the age of these conclusions in the way that coal deposits categories. As explained by its rich indicate humid forests, coral reefs tropical speciation in SE—Asia, the subgenus climates, and sandstones, evaporites and Thysanomitrion seems to be the youngest Red Beds desert climates. Maps of the branch, indeed. However, the two coal deposits from different geological representatives of subgenus periods by Seyfert & Sirkin (1973) show Campylopidulum each with one species that there must have been a continuous in the dry savannah regions of the Neotro- humid climate in the present subantarctic pics and Africa (Frahm 1986) seem to go since the late Palaeozoic, which may back on an origin in the dry climatic periods indicate (together with the high percentage of the Mesozoic and seem to have of primitive taxa) an origin of Campylopus developed from the same Gondwanalandic along the south coast of Gondwanaland. ancestor. At least there was considerable The next diversification is indicated by speciation in subg. Campylopus sect. dry adapted species with a present wide Homalocarpus in the Andes, probably by (gondwanalandic) range from South and a spreading of subantarctic ancestors in Central America to Africa and India. This this mountain chain in Tertiary, although type of range may go back to the Jurassic this group is considered here as the most period about 150 Mio years ago, when the primitive and probably also oldest group. continents where still connected. Examples are Campylopus pilifer Brid., C. savannarum (C. Müll.) Mitt., or ancestor 6. Origin and evolution of the genus of species pairs occurring in savannahs such as C. carolinae Grout in Brazil and It would be worth to speculate about the C. perpusillus Mitt. in Africa. It could be age of the genus and species and the that also mesic forest species such as C. probable time of its origin. Since there are fragilis (Brid.) B.S.G. or C. flexuosus no species in Campylopus with a pangaean (Hedw.) Brid. were derived in this period distribution, the genus itself should be by invading the drier interior of Gondwa- younger than 200 Mio years. naland. A reason for this migration and An indication of the presumed origin of adaptation to drier habitats could be the the genus may be a region with the most drainage of swamp forest pressing the primitive forms, with a maximum of species into new habitats (probably continuity of the climate through the past combined with a considerable number of geological periods and a continuity of extinctions). It could be argued that these habitats. The most primitive forms widespread ranges are based on relatively according to the cladistic analysis are recent long distance dispersal. However, species of the section Homalocarpus with this would not explain why Campylopus a center in the subantarctic, where 12 of 14 fragilis, for instance, does not occur in the species belong to this group. mountains of SE-Brazil (which should be A reconstruction of the palaeoclimate easily accessible for long distance allows conclusions whether the climate at dispersal) but is replaced there by a local, any time was humid, either cool or tropical, morphologically different subspecies. It or arid, and thus less favourable for would also not explain why Campylopus bryophytes in general or only for adapted flexuosus is not present in SE-Brazil, species. Furthermore it is important to allthough it has a wide, nearly pantropical know to which extent humid climates range. Therefore these wide ranges seem 100 not to be the result of long distance dispersal The most recent speciation probably took but of previously continuous ranges at a place at the subspecies level on isolated time when the continents where still mountain massifs such as the Serra do partially connnected. Itatiaia in SE-Brazil (Campylopus fragilis There are some examples for disjunctions (Brid.) B.S.G. ssp. fragiliformis (J.-P. of species between SE-Brazil and E- Frahm) J.-P. Frahm) or young volcanic Africa, where they occur in vicariant islands such as the Galapagos Islands (C. subspecies or species. Examples are pilifer Brid. ssp. galapagensis (J.-P. Frahm Campylopus trachyblepharon (C. Müll.) & Sipman) J.-P. Frahm). Mitt. ssp. trachyblepharon in SE-Brazil There is no convincing indication for spe- and ssp. comatus (Ren. & Card.) J.-P. ciation during the Quaternary, in spite of Frahm in E-Africa, C. julaceus Jaeg. ssp. strong climatic changes and fluctuation of julaceus and ssp. arbogastii (Ren. & Card.) vegetation belts. It could be that a local J.-P. Frahm, C. controversus (Hampe) endemic like Campylopus cleefii from the Jaeg. and C. stenopelma (C. Müll.) Rehm. colombian páramo and apparently derived ex Par. These species must have been from the montane C. arctocarpus present when the South Atlantic had just (Hornsch.) Mitt. has evolved only in one opened and there was a continuous shore- paramo system, which extended to lower line stretching from SE-Brazil to Malagasy, elevations in cold phases of the Pleistoce- about 135 Mio years ago. Separation of ne. However, these fluctuations have pro- the continents lead to isolation and to bbaly only had an influence on the geographical races. expansion of present ranges. Relicts of the former Campylopus flora of Based on this distribution-based estimation the coastal areas of South America just of the age of the 65 neotropical species of after the split of Gondwanaland are Campylopus, 60% have been evolved in preserved in SE-Brazil. This region is the Tertiary, 30% in Cretaceous, 2% in characterized by 13 endemic species, of Jurassic and 8% in the Triassic, which 8 can easily be derived from species demonstrating that the Tertiary speciation with present subantarctic ranges (Frahm was the most important (Frahm, in prep). in prep.). SE-Brazil had also a continuous This should not, however, lead to the humid climate through the past geological conclusion that the number of species of periods (Nacib Ab’Saber 1982) and thus Campylopus has raised through the past species could survive here (at least in part) 180 Mio years. There were almost certainly since the Mesozoic. numerous extinctions , for example in the Old species with an age of 100 Mio years Quaternary by lowering or raising of or less may be those which are confined to sealevels, lowering and raising of the Neotropics or tropical Africa, where temperatures causing splitting of they have a wide range. Examples are continuous vegetation belts (like Campylopus subcuspidatus (Hampe) rainforests), and expansion of alpine belts. Jaeg., C. richardii Brid. and C. There are indications of species showing lamellinervis (C. Müll.) Mitt. in the Neo- scattered distributions, which probably are tropics. extinct in parts of their ranges, like C. Younger species (with an age of 70 Mio subcuspidatus in South America. Other years or less) are presumambly those of species are confined to extremely small young Mesozoic islands such as the ranges like C. uleanus (C. Müll.) Broth., Caribbean Islands or of mountain massifs C. viridatus (C. Müll.) Broth. and C. of Teriary age. 50% of all neotropical widgrenii (C. Müll.) Mitt. in SE-Brazil, species belong to the andine element and each known from only 2-4 localities, or therefore the richest speciation took place have a wide range but with only a few during Tertiary. records of small, sterile populations, like 101

C. oerstedianus (C. Müll.) Mitt. a relic —————— 1983. A new infrageneric classification in the genus tethyan range from central America to Campylopus Brid. Journal of the Hattori Botanical Laboratory Europe, or the Mexican population of C. 54: 207-225. japonicus Broth. trapped in Mexico as a —————— 1984. Phytogeography of European Campylopus species. relict of a previous circum-pacific range. Proceeding of the Third Meeting of Bryologists from Central and These are the really endangered species Eastern Europe, Praha, pp. 191-212. and may be the next candidates for —————— 1985. The ecological significance of the costal anatomy extinction. in the genus Campylopus. Abstracta Botanica 9, Suppl. 2: 159- 169. 6. Conclusion —————— 1985a. The worldwide range of Campylopus shawii Wils. Journal of Bryology 13: 329-332. Coming back to the statement by Schuster —————— 1986. Campylopus Brid. 2. Subg. Campylopidulum Vital. (1984), who called Campylopus a modern Nova Hedwigia 43: 221-227. and successful genus. Apparently it is —————— 1987. Which factors control the growth of epiphytic successful. This is expressed by the high bryophytes in tropical rainforests? Symposia Biologica number of species, and the broad Hungarica 35: 639-648. geographical and ecological amplitude. —————— 1987a. Oekologische Studien ueber die epiphytische This success is due to anatomical and Moosvegetation in Regenwaeldern NO-Perus. Beih. Nova morphological features, of which the Hedwigia 88: 143-158. structural plasticity of the costa probably —————— 1988. The subantarctic and southern hemispheric plays the most important role. The genus species of Campylopus (Dicranaceae), with contributions to the itself, however, cannot be called a modern origin and speciation of the genus. Journal Hattori Botanical genus. The interpretation of the worldwide Laboratory 64: 367-388. distribution shows that it probably evolved ————— in prep. Origin and distribution of Neotropical species of on the Gondwana continent and therefore Campylopus. has probably been already present in Frahm, J.-P., M. Giese, M. Padberg, T. Koponen and Mesozoic ages. The main speciation, D.H.Norris 1985. Bryophyte flora of the Huon Peninsula, however, may be of Tertiary origin, caused Papua New Guinea. IX. Atractylocarpus, Bryohumbertia, by the uplift of mountain systems and Campylopodium and Campylopus (Dicranaceae, Musci). Acta continental drift, and thus diversification Botanica Fennica 131: 63-88. is relatively modern. Insofar Campylopus Frey, W. & J.-P. Frahm 1987. The twist mechanism in the might be called one of the most successful cygneous setae of the genus Campylopus. Morphology, structure genera of mosses with relatively recent and function. Nova Hedwigia 44: 291-304. diversification. Nacib Ab’Saber, A. 1982. The Paleoclimate and Paleoeco- logy of Brazilian Amazonia. In: G.T.Prance (ed.) Biological Diversification in the Tropics. Proceedings of the Fifth Parts of the manuscript have been prepared during a stay at the International Symposium of the Association for Tropical Biology University of Alberta. I wish to thank Dr. D.H.Vitt for providing held at Macuto Beach, Caracas, Venezuela, 1979, pp. 41-59. me with working facilities for this time, support with literature, Peterson, W. 1979. A revision of the genera Dicranum and valuable suggestions and discussions, and also for correcting the Orthodicranum (Musci) in North America north of Mexico. English text. Microtome transverse sections were made by M. Ph.D. Thesis Univ. of Alberta. Campenot. Raven, P.H. & D.I. Axelrod 1974. Angiosperm Biogeo- graphy and Past Continental Movements. Annals of the Missouri Literature cited: Botanical Garden 61: 539-673. Robinson, H. 1985. The structure and significance of the Corley, M.F.V. & J.-P. Frahm 1982. Taxonomy and leucobryaceous leaf. Monographs in Systematic Botany from world distribution of Campylopus pyriformis (Schultz) Brid. the Missouri Botanical Garden 11:111-120. Journal of Bryology 12: 187-190. Schuster, R.M. 1972. Continental Movements, “Wallace’s Frahm, J.-P. 1980. Synopsis of the genus Campylopus in Line” and Indomalayan-Australasian dispersal of Landplants: North America North of Mexico. The Bryologist 83: 570-588. Some eclectic concepts. Bot. Rev. 38: 3-86.