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DICRANACEAE

(J.-P. Frahm)

Plants variable in size and appearance, 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, urn 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.

Discussion. The Dicranaceae consist worldwide of about 50 genera with more than 1000 species; they are represented in tropical Africa by 26 genera and about 218 species, of which 90 belong to Leucoloma and 39 to Campylopus. The species grow on open soil, rotten wood, peat, and rocks, preferably at higher altitudes in upper montane and subalpine regions; most species are characteristic for acidic substrates. The family is closely related to Ditrichaceae, from which it is difficult to separate.
    Many species in some genera are known only in sterile condition; therefore the determination is usually based on leaf characters. Identification of some genera and species requires transverse sections of the costa.
    A recent molecular-systematic study (Stech, 1999) revealed that the subfamilies Dicranoideae and Campylopodioideae are monophyletic whereas Rhabdoweisioideae and Dicranelloideae appear as polyphyletic. A subfamily Paraleucobryoideae is not supported by the molecular data.

Literature. Frahm, J.-P. 1993. Taxonomic Results of the BRYOTROP Expedition to Zaire and Rwanda. 17. Andreaeaceae, Bruchiaceae, Dicranaceae, Rhizogoniaceae, Bartramiaceae, Rhacocarpaceae, Hedwigiaceae, Cryphaeaceae, Leucodontaceae. Tropical Bryology 8: 153-170. Stech, M. 1999. A reclassification of Dicranaceae (Bryopsida) based on non-coding cpDNA sequence data. Journal of the Hattori Botanical Laboratory 86: 137-159.

Please note: there are three options for couplet 9.

Anisothecium Mitt.

A genus of about 40 species of which half of the number is little known. The genus is often included in Dicranella, from which it differs by sheathing leaf bases which are suddenly contracted into a long acumen. Three species are known from tropical Africa: A. ugandae P.de la Varde from Central Africa (Potier de la Varde, 1926), A. horridum P.de la Varde from Central African Republic (Potier de la Varde, 1935) and A. madagassum Thér. from Madagascar (Thériot, 1930).

Plants mostly small, forming loose to dense tufts, less often gregarious, green, yellowish-green or brown. Stems erect, few branched by innovations, occasionally radiculose below; central strand present. Leaves small and ± distant below, distally larger and crowded, erect to erect-spreading flexuose, secund or not, often only slightly more spreading when wet, oblong- to ovate- or triangular-lanceolate to narrowly lanceolate-subulate, 1-4 mm long, apex acute to bluntly obtuse; margins plane to reflexed below, subula inflexed, incurved or channelled, entire to distally dentate-serrulate; costa subpercurrent or percurrent, rarely excurrent, 1/3 or less width of leaf base; laminal cells thick-walled, upper cells rectangular to quadrate or subquadrate, smooth or bulging papillose; lower and basal cells long rectangular, smooth; alar cells undifferentiated. Dioicous. Perichaetia terminal, leaves larger, subsheathing to convolute. Seta elongate, 5-15 mm long, erect, smooth. Capsule erect or occasionally inclined, symmetric or asymmetric and curved, urn subglobose to ovoid-cylindrical, 0.7-1.5 mm long, smooth or furrowed, neck sometimes distinct, occasionally gibbous. Operculum conic-short to long rostrate. Peristome teeth divided ca. 1/2 or slightly more into 2-3 segments, vertically striate-pitted below, distally papillose or spiculose. Calyptra cucullate, smooth and naked, base entire. Spores lightly to coarsely papillose.

Habitat. On bare soil and soil covered rocks in open sites, from the lowland to high montane belt.

Discussion. Sterile plants can be confused with Microcampylopus, which differs in its cygneous setae but is almost indistinguishable when sterile.

Literature. Potier de la Varde, R. 1926. Mousses récoltées par M. le Dr. Olov Hedberg, en Afrique orientale, au cours de la mission suédoise de 1948. Arkiv för Botanik utgivet av K. Svenska Vetenskapsakademien 3(8): 125-204. [illustration of A. ugandae]. Potier de la Varde, R. 1935. Recoltes bryologiques aux environs de Bozoum (Deuxieme note.). Revue Bryologique et Lichénologique 7: 226-237. Theriot, I. 1930. Septiéme contribution à la flore bryologique de Madagascar. Recueil des Publications de la Société Havraise d'Études Diverses 1929: 99-121.

Aongstroemia Bruch, Schimp. & W.Gümbel

A genus of 7 species mainly in the arctic or at higher elevations . Two species in tropical Africa: A. filiformis (P.Beauv.) Wijk & Margad. and A. julacea (Hook.) Mitt. (Both in SE Africa and also in the Neotropics, A. julacea also in Eurasia).

Plants small, slender, loosely caespitose or growing scattered, yellow-green. Stems erect and slender, julaceous, usually unbranched. Leaves oval to oblong, apex obtuse or broadly acute, densely appressed, 0.5-1.5 mm long; margins plane, entire or denticulate; costa ending before leaf apex or shortly excurrent in lower leaves and longly excurrent in upper leaves; upper laminal cells smooth, rhomboidal to vermicular, incrassate, basal laminal cells larger, rectangular to subquadrate, walls thickened; alar cells undifferentiated. Sporophytes not known in Africa.

Habitat. On open soil, A. filiformis in forest, A. julacea in grassland above the forest line.

Discussion. The genus is easily recognised by small, slender plants with julaceous stems and leaves closely appressed whether dry or wet, narrow costa, thick-walled upper laminal cells, and undifferentiated alar cells. Aongstroemia julacea has rounded leaves with dentate upper margins, A. filiformis has oblong leaves with shortly excurrent costa and entire margins.

Literature. Magill, R.E. 1981 - see general ref. [key, illustrations].

Aongstroemiopsis M.Fleisch.

A monotypic genus with only A. julacea (Dozy & Molk.) M.Fleisch. This species occurs in the Himalaya, southern China and Malesia and was said to be endemic to SE Asia, but has since been recorded from Lesotho.

Plants small, consisting of scattered julaceous plants with shoots less than 8 mm long. Stems simple. Leaves broadly lanceolate, about 0.5 mm wide and 1 mm long, entire, quickly narrowed into a blunt apex; costa stout, percurrent; upper laminal cells quadrate to shortly rectangular, thin-walled, narrower at margins; basal laminal cells longer; alar cells not differentiated. Monoicous. Sporophytes small. Seta 3 mm long, sinuate. Capsule 1.5 mm long, almost erect, somewhat curved, shortly cylindrical. Operculum short, blunt. Peristome lacking. Spores 18-20 µm in diameter.

Habitat. On soil at the base of boulders in a moist alpine meadow 2860m.

Discussion. This genus differs from Aongstroemia in its eperistomate capsules and conical lid. The capsules and setae are said to be smaller and the spores larger in the African plants as compared with material from SE Asia.

Literature. Magill, R.E. 1987. Musci austro-Africana III. Alpine mosses of Lesotho. Journal of Bryology 14: 527-530.

Atractylocarpus Schimp. ex Milde

A genus of 9 species worldwide, mostly in subalpine and alpine regions of the tropical mountains, only A. alpinus in Europe. Two species in Africa, of which A. madagascariensis (Thér.) Padberg & J.-P.Frahm is confined to southern Africa and East African islands and A. alticaulis (Broth.) R.S.Williams to Central Africa.

Plants slender, in dense tufts, dark green. Stems erect, almost unbranched, to 6 cm high, tomentose; central strand present. Leaves equally foliate, erect-spreading when wet, rarely falcate-secund, from an ovate base longly setaceous, 4-10 mm long; margins entire below, dentate at tips; costa broad, filling half of leaf base, in transverse section with dorsal and ventral stereids and median guide cells; laminal cells smooth, upper laminal cells rectangular, elongate rectangular and thin-walled at base; alar cells weakly differentiated. Autoicous or Dioicous. Perichaetia terminal, leaves similar but smaller. Seta elongate, 10-28 mm long, twisted in the upper part, golden-yellow. Capsule erect, symmetric, urn short cylindrical, 1-2 mm long, furrowed when dry: stomata absent; annulus absent. Operculum longly rostrate, as long as the urn. Peristome teeth divided ca. 2/3, outer surface vertically to obliquely striate at base, papillose at tips, inner surface coarsely papillose. Calyptra cucullate, naked, entire at base. Spores papillose, 14-18 µm.

Habitat. Atractylocarpus alticaulis grows on humus and rotten logs in high montane forests and subalpine forests (2500-)3000-3300(-4000?) m and A. madagascariensis grows on humus, soil, rocks (including lava) and living and dead trees, from (610-)1800-2270 m.

Discussion. All species are keyed, described and illustrated in Padberg & Frahm (1985). The genus resembles Dicranodontium vegetatively, but has a longer, straight seta which is only twisted in the upper part but not sinuose and curved, and a long cylindrical and not ovoid urn.
    The name Atractylocarpus was conserved against Metzleria although described later in the same year. However, the type species of the genus Atractylocarpus proved to differ from all other species included in the genus and belongs to the genus Campylopodiella. To save the use of Atractylocarpus, a proposal to amend this genus was made by Frahm & Isoviita (1988), and this was eventually accepted.
    Allen (1994), in agreement with Williams (1913), included Atractylocarpus in Dicranodontium, based on the similarity of the gametophyte.

Literature. Allen, B. 1994. Moss Flora of Central America. Part 1. Sphagnaceae-Calymperaceae. Monographs in Systematic Botany viol. 49: 1-242. Frahm, J.-P. & Isoviita, P. 1988. Proposal to amend Atractylocarpus, nom. cons. (Musci, Dicranaceae). Taxon 37:967-969. Padberg, M. & Frahm, J.-P. 1985. Monographie der Gattung Atractylocarpus Mitt. (Dicranaceae). Cryptogamie, Bryologie. Lichénologie 6: 315-341 [keys, illustrations]. Williams, R.S. 1913. Dicranaceae, Leucobryaceae (Bryales). North American Flora 15(2): 77-166.

Brothera Müll.Hal.

A monotypic genus. The only species, B. leana (Sull.) Müll.Hal., was known from North America, Mexico and Asia and was recently found in Malawi (Pócs 1993).

Plants small, less than 1 cm tall, in dense tufts, pale green or yellow. Stems usually simple. Leaves erect-flexuose, linear-lanceolate, to 3 mm long, concave below, subtubulose above; margins incurved, entire, toothed at apex; costa long excurrent, ca. 1/3 width of leaf base, rarely more; in transverse-section with a layer of median chlorocysts and ventral and dorsal rows of hyalocysts; upper laminal cells long rectangular; basal cells rectangular; alar cells not differentiated. Vegetative propagation by clusters of small brood leaves in the axils of the upper l stem leaves. Dioicous. Sporophytes not known from Africa.

Habitat. On shady granite cliff in forest at 1730 m altitude.

Discussion. The genus is recognised by small pale plants with clusters of brood leaves in the axils of the upper stem leaves, in habit similar to Campylopus fragilis, and a very typical transverse section of the costa with median chlorocysts and ventral and dorsal rows of hyalocysts.

Literature. Müller, P. & Frahm, J.-P. 1987. A review of the Paraleucobryoideae (Dicranaceae). Nova Hedwigia 45: 283-314. [illustration] Pócs, T. 1993. Brothera leana (Sull.) C. Müll., a Laurasian species in tropical Africa. Bulletin du Jardin Botanique National de Belgique 62: 221-224.

Bryohumbertia P.de la Varde & Thér.

A pantropical genus of three species, which is represented in tropical Africa mainly by B. flavicoma (Hornsch.) J.-P.Frahm. B. filifolia (Hornsch.) J.-P.Frahm, widespread in the Neotropics, is only rarely recorded from Madagascar, Réunion and Mauritius.

Plants small or robust, in loose short to tall tufts, dark green. Stems erect, mostly single, young plants comose foliate, older ones verticillate foliate, the leaf whorls often indistinct in B. flavicoma but very distinct and in 3-6 in B. filifolia. Leaves spreading to erect or appressed, from a short concave ovate base long subulate, 4-12 mm long, apex long acuminate; margins serrate in the upper part; costa strong, filling 1/3 of leaf width, percurrent or excurrent; basal laminal cells rectangular, incrassate, upper laminal cells shortly rectangular; alar cells oval-short rectangular, incrassate, dark rusty-red. Dioicous. Seta elongate, 9-14 mm long, usually erect but sinuose when dry, flexuose and curved when wet, yellowish. Capsule asymmetric, urn cylindrical, 1.5-2 mm long, curved, furrowed when dry and empty, strumose; annulus present. Operculum long rostrate, as long as the urn, oblique. Peristome teeth on outer surface striate, inner smooth. Calyptra cucullate, 2.5-3 mm long, smooth, base fringed with long hairs. Spores about 13 µm, slightly papillose.

Habitat. On soil, humus and logs in forests; from the lowlands to the high montane belt (2700 m).

Discussion. The genus Bryohumbertia resembles certain species of Campylopus but differs in the longer setae, a longly rostrate operculum and a smooth inner surface of the peristome teeth. Recent preliminary molecular studies reveal that Bryohumbertia (represented by B. flavicoma) is not separated at genus level (Stech, 1999).

Literature. De Sloover, J.L. 1976. Note de bryologie africaine. VII. Pseudephemerum, Bryohumbertia, Eucladium, Streptopogon, Ptychomitrium, Rhachithecium, Antitrichia, Pterogonium, Lindigia, Distichophyllum. Bulletin du Jardin Botanique de l'Etat 46: 427-447. [illustration of B. flavicoma] Frahm, J.-P. 1982. A reinterpretation of Bryohumbertia P. de la Varde et Thér. Cryptogamie, Bryologie. Lichénologie 3: 365-369 [key]. Stech, M. 1999 - see family ref.

Bryotestua Thér. & P.de la Varde

A genus with 2 species (B. brevicuspis Thér. & P.de la Varde and B. longicuspis Thér. & P.de la Varde), so far known only from the type localities in the Central African Republic.

Plants 10 mm tall, in dense tufts. Stems erect, tomentose below; in transverse section with large lax cells, without central strand. Leaves erect patent, lanceolate, from an ovate or lanceolate base subulate, apex longly acuminate; margins entire or slightly dentate in the uppermost apex, plane below and revolute in the upper part; costa filling 1/6-1/4 width of leaf base, excurrent, in transverse-section with groups of median stereidal cells and ventral and dorsal layers of large, empty cells; alar cells lacking; basal laminal cells rectangular, 5 times longer than broad, smooth, upper laminal cells shorter, hexagonal. Dioicous. Perichaetia terminal, perichaetial leaves not differentiated.

Habitat. On soil (!) in arid habitats

Discussion. The genus is mainly characterised by the transverse section of the costa, which makes it probable that the plants belong to the Dicranaceae. The structure of the costa much resembles Campylopodiella, a genus known from tropical America and the Himalayas. The authors placed Bryotestua tentatively in the Anisothecioideae.

Literature. Potier de la Varde, R. 1937. Bryotestua Thér. et P. de la V., genus novum familiae Dicranacearum. Bulletin de la Société Botanique de France 84: 558-562. [key, illustration]

Campylopus Brid.

A genus in which the Index Muscorum listed more than 700 legitimate species worldwide, which have been reduced to about 150 species. Thirty-nine species occur in Africa south of the Sahara.

Plants from a few mm to 10 cm tall, in tufts, light to dark green, yellow or golden, occasionally blackish-brown. Stems erect, rarely branched, often densely tomentose; central strand present; rhizoids reddish-brown or occasionally whitish, smooth or papillose. Leaves erect patent to appressed, lanceolate, from an ovate or lanceolate base subulate, apex longly acuminate; margins entire, in some species serrulate to serrate in the upper part; costa strong, filling 1/3-4/5 width of leaf base, percurrent to commonly long excurrent, excurrent tips concolorous or hyaline, smooth, ribbed or lamellose at back, in transverse-section with ventral stereids or hyalocysts, median deuter cells and dorsal stereidal or non-stereidal cells; alar cells usually differentiated, hyaline or reddish, inflated or not; laminal cells smooth, basal laminal cells hyaline and thin-walled or incrassate, sometimes with pitted walls, sometimes narrower at margins, upper laminal cells quadrate to shortly rectangular, oval or rhomboid to elongate rhomboid. Vegetative propagation by microphyllous deciduous branches, deciduous leaf or stem tips, clusters of brood leaves in the axils of the upper leaves or rhizoidal gemmae. Dioicous. Perichaetia terminal, perichaetial leaves differentiated and forming comal tufts or not differentiated, not forming comal tufts. Seta 5-15 mm long, smooth, sinuose when dry and cygneous when wet, twisted. Capsule exserted, urn ovoid to short cylindrical, erect or curved, often strumose at base; exothecial cells thick-walled, stomata absent; annulus present. Operculum rostrate. Peristome teeth divided half way, outer surface striate at base and papillose at tips or divided to the base and papillose throughout. Calyptra cucullate, smooth, base entire or fringed with long hairs. Spores papillose, about 13 µm in diameter.

Habitat. On soil, humus, rotten log, rocks, a few species also epiphytic; from lowlands, dry savannahs and semi-deserts to wet montane and subalpine forests and alpine regions to more than 4000 m; most species occur at higher elevations.

Discussion. The genus is characterised by the broad costa and the cygneous, twisted setae which produce uncoiling movements when wetted. The anatomy of the costa is very different and probably an adaptation to different habitats. Large ventral hyalocysts function for storing water in humid habitats but ventral stereids provide stability against shrinking in arid environments. Therefore transverse sections of the costa are required for the identification of many species. There are even species pairs which differ mainly by the structure of the costa, the presence or absence of dorsal lamellae or the presence or absence of stereidal cells. Several species are not known with sporophytes but propagate by various kinds of brood organs.
    Certain species of Campylopus vegetatively resemble Pilopogon, Dicranodontium and Atractylocarpus and can hardly be differentiated from the latter genus without experience. The setae of Pilopogon are straight whereas those of Campylopus are cygneous.

Literature. Frahm, J.-P. 1985. Afrikanische Campylopus-Arten (Dicranaceae, Musci). Bryophytorum Bibliotheca 31: 1-216. [key, illustrations] The nomenclature of this monograph of the African species is outdated in some respects because of later revisions and must be checked against: Frahm, J.-P. 1999. A type catalogue of Campylopodioideae and Paraleucobryoideae (Musci, Dicranaceae), Part II, Campylopus. Tropical Bryology 16: 17-102.

Cladophascum Dixon ex Sim

A monotypic genus with only C. gymnomitrioides, which was originally described in Aongstroemia.

Plants small, forming loose tufts, green to yellowish green. Stems to 1 cm tall, julaceous, little and irregularly branched. Leaves oval, concave, closely appressed to the stem, giving the plant an appearance of Aongstroemia or Plagiobryum, only 0.2-0.4 mm long, apex obtuse to broadly rounded, margins entire; costa reaching to midleaf; upper laminal cells almost quadrate, incrassate, hyaline and thin-walled at margins, forming a border 2-3 cells wide; basal laminal cells larger, quadrate or short rectangular. Synoicous. Perichaetia lateral, large, perichaetial leaves oval but suddenly cuspidate, with excurrent costa. Seta only 0.1 mm long. Capsule erect, pyriform, with short neck, 0.8 mm long, with numerous stomata. Operculum conic-long rostrate, oblique. Peristome lacking. Calyptra mitriform. Spores highly papillose, 52-57 µm.

Habitat. On soil in grassland in Namibia, Zimbabwe, adjacent parts of the Republic of South Africa, and Tanzania.

Discussion. The genus differs from Aongstroemia by the stegocarpous capsules. Magill (1981) placed the genus in the Trematodontoideae (here Bruchiaceae) based on the capsule morphology.

Literature. Magill, R.E. 1981. - see general ref. [illustration]

Dicranella (Müll.Hal.) Schimp.

A genus of almost a 100 species worldwide, of which 27 are recorded from tropical Africa. Anisothecium, which is included by some authors in Dicranella, is treated here separately.

Plants small, in loose or dense tufts, light to dark green or yellowish-green. Stems erect, rarely branched, with central stand. Leaves smaller below, larger and comose above, erect-spreading, flexuose, or homomallous, oblong, obovate to lanceolate or narrowly lanceolate, 1-4 mm long, apex subulate; margins plane, entire; costa percurrent or excurrent, 1/3 or less width of leaf base; upper laminal cells thick-walled, rectangular to quadrate or subquadrate, ± smooth ; basal laminal cells rectangular, smooth; alar cells not differentiated. Dioicous. Perichaetia terminal, leaves similar to stem leaves but larger, with sheathing bases. Seta 5-15 mm long, straight, yellow or red. Capsule erect and symmetric or inclined or asymmetric and curved, urn subglobose to ovoid-cylindrical, 0.7-1.5 mm long, smooth or furrowed when dry, neck sometimes distinct, occasionally strumose. Operculum short to long rostrate. Peristome teeth divided ca. 1/2 or slightly more into 2-3 segments, vertically striate-pitted below, distally papillose or spiculose. Calyptra cucullate, smooth, entire at base. Spores lightly to coarsely papillose.

Habitat. On soil or soil covered rocks in open sites, from the lowland (in southern Africa) to the alpine belt, in Central Africa from 1800 to 4400 m.

Discussion. The genus much resembles Anisothecium, which differs by leaves with sheathing leaf bases which are suddenly contracted into the subula. The sporophytes are identical. Anisothecium is therefore commonly included in or treated as a subgenus of Dicranella, although Brotherus (1924) placed both genera in different subfamilies. Microdus resembles Dicranella vegetatively and is therefore also included in Dicranella by some authors but has a different peristome architecture.

Literature. Brotherus, V.F. 1924. - see general ref.

Dicranoloma (Renauld) Renauld

A genus with more than 100 species distributed in the Southern Hemisphere, mainly in Australasia. Five species occur in tropical Africa, four of which have been described from Africa and are known only locally. Only D. billardierei is more widespread, from South Africa to the mountains of Central Africa.

Plants large, in tufts or cushions, yellow. Stems erect, to more than 10 cm tall, simple or somewhat branched. Leaves falcate-secund, from ovate base narrowly lanceolate, to 7 mm long, concave; margins sharply serrate in the upper third, limbate in the lower 2/3; costa narrow, percurrent; upper laminal cells smooth and thick-walled, elongate-oval, weakly porose or not; basal laminal cells oblong-linear, strongly porose; marginal cells forming a border of 3-4 rows of elongate, hyaline cells; alar cells large, rectangular, reddish brown. Autoicous. Perichaetia terminal. Perichaetial leaves sheathing, with obtuse apex. Seta 15–20 mm long. Capsule curved, asymmetric, strumose, reddish, 3 mm long; annulus persistent. Operculum long rostrate. Peristome teeth vertically striate-papillose, cleft nearly to the middle. Calyptra cucullate, smooth. Spores spherical, papillose, 12-15 µm.

Habitat. On humus or soil in montane forests. D. billardierei grows epiphytically and forms huge 'mossballs' 1-2 m in diameter (!) on stems and branches in humid habitats at elevations between 1800 and 3200 m.

Discussion. Dicranoloma in appearance resembles Dicranum, from which it is distinguished by the absence of a central stand, presence of a narrow costa, and a narrow border of elongate hyaline cells along the leaf margin. It can easily be confused with Dicranum johnstonii, with which it can grow intermixed, from which it is distinguished in addition to the characters mentioned by the elongate pitted laminal cells.
     Norris and Koponen (1989) confined the use of the name Dicranoloma to 6 species in northern Australia and New Caledonia; in their opinion all other species should be combined into Dicranum, with the consequence that Dicranum would not be a holarctic genus anymore but bicentric in distribution. Klazenga (1999) disagreed with this view in a wide-ranging revision of the genus in Malesia, and reverted to a concept similar to Renauld's original description of the genus, which is supported here.

Literature. Klazenga, N. 1999. A revision of the Malesian species of Dicranoloma (Dicranaceae, Musci). Journal of the Hattori Botanical Laboratory 87: 1-130. Norris, D.H., Koponen, T. 1989. Typification of Dicranoloma Ren., a small genus of mosses from Northern Australia and New Caledonia. Acta Bryolichenologica Asiatica 1: 1-14.

Dicranum Hedw.

Six species in tropical Africa, of which 4 are insufficiently known. The genus includes almost 100 species, mainly distributed in cool temperate regions of the northern hemisphere.

Plants tall, robust, in tufts, light to dark green or golden-yellow. Stems erect or rarely branched, usually densely tomentose with whitish to red-brown rhizoids. Leaves spreading, flexuose, or falcate-secund, lanceolate, ending in a narrow, long acumen, 5-13 mm long, margins entire or serrate in the upper third of the leaf; costa percurrent to short excurrent, ca. 1/5 or less the width of leaf base, entire or toothed at back in the apex, in cross-section with a median band of guide cells and ventral and dorsal bands of stereids; upper laminal cells quadrate, oval or short elongate, sometimes slightly pitted, smooth; basal laminal cells rectangular, large, usually strongly pitted; alar cells well developed, quadrate or inflated, hyaline or reddish. Dioicous. Perigonia bud like (dwarf males), attached to tomentum. Perichaetia terminal, leaves convolute, usually differentiated from stem leaves. Seta 1 to often 2-4 per perichaetium, elongate, 20-60 mm long, smooth. Capsule inclined and curved, urn cylindrical, 3-5 mm long, annulus absent or present and persistent. Operculum long rostrate, often equal to urn length. Peristome teeth divided to ca. 1/2, vertically striate-pitted below, papillose above. Calyptra cucullate, naked. Spores spherical, papillose.

Habitat. On soil, humus and rotten wood in montane and subalpine forests, 1800-3850 m.

Discussion. The genus resembles Dicranoloma, from which it is distinguished by the lack of a row of elongate cells along the leaf margins. Only two species are at all common, D. acanthoneuron Müll.Hal. and D. johnstonii Mitt., which are widely distributed in the high montane and subalpine regions of Central Africa.

Holomitrium Brid.

A genus of about 50 species worldwide, mainly epiphytes in tropical regions, of which 12 have been reported or described from tropical Africa. The species are concentrated in East Africa and the East African islands: 8 of the 12 species are reported from Madagascar. The others are confined to the southern part of tropical Africa (Angola, Zimbabwe), with only two found in Central Africa.

Plants medium sized to large, forming dense tufts, dark green, to light green or yellowish-brown. Stems erect, frequently branched, densely tomentose below; central strand present. Leaves squarrose or flexuose when dry, erect-spreading when wet, from an ovate base narrowly lanceolate, keeled or channelled above, concave below; margins plane, serrate, dentate, crenulate or entire; costa strong, percurrent to short excurrent, ca. 1/4 or less width of leaf base, often toothed distally on back, in cross-section with a median band of guide cells and ventral and dorsal stereids; upper laminal cells quadrate, basal laminal cells elongate and strongly porose; alar cells enlarged, red-brown. Pseudautoicous. Perigonia bud-like, attached to stem or leaf tomentum. Perichaetia terminal, leaves usually very long, from broad base abruptly acuminate, convolute, sheathing the seta. Seta 1(-2) per perichaetium, erect. Capsule erect, urn short to long cylindrical, phaneroporous stomata at base of urn; annulus absent. Operculum rostrate. Peristome teeth inserted below urn mouth, perforated or cleft to the base, papillose. Calyptra cucullate. Spores lightly papillose.

Habitat. Epiphytic on branches and trunks of trees and shrubs, 800 to 2500 m.

Discussion. The species of Holomitrium resemble in appearance those of Symblepharis or Pseudosymblepharis (Pottiaceae), which grow in similar habitats. They are distinguished from Pseudosymblepharis by smooth, not papillose, upper laminal cells and from Symblepharis by the long, convolute perichaetial leaves.

Leptotrichella (Müll.Hal.) Lindb.

A genus in which over 60 species were recognised, of which 11 occur in tropical Africa. The 'Checklist of Mosses' (Crosby et al. 1999) enumerates only 11 species worldwide, 2 of them from tropical Africa. Until recently (Ochyra 1997) this genus was known as Microdus.

Plants small, loosely caespitose. Stems 2-4 mm high, erect. Leaves erect spreading when wet, appressed when dry, oblong to lanceolate, 1-2 mm long, apex acute to obtuse-rounded, entire, dentate or serrate; margins plane; costa strong, ending below apex, 1/4-1/5 width of leaf base; upper laminal cells quadrate to short rectangular, smooth, incrassate, basal laminal cells larger, rectangular, thin-walled; alar cells lacking. Dioicous. Perichaetia terminal, leaves larger but not differentiated. Seta erect, elongate, to 4 mm long. Capsule erect or suberect; urn oval to short cylindrical, 0.6-1 mm long; annulus present. Peristome teeth irregular, cleft or perforated, usually short, 50–150 µm long, rudimentary, rarely absent, papillose. Calyptra cucullate, naked and smooth, base entire. Spores ca. 20 µm, papillose.

Habitat. On open soil in grasslands, on road banks, often in disturbed sites; 700–2000 m.

Discussion. The genus is a small Dicranella in most respects and is therefore not distinguished by some authors (as with Anisothecium) but differs in its short, papillose peristome.

Literature. Crosby, M.R., Magill, R.E., Allen, B. & He, S. 1999. - see general refs. Ochyra, R. 1997. Leptotrichella replaces Microdus (Musci, Dicranaceae). Fragmenta Floristica et Geobotanica 42: 559-565.

Leucoloma Brid.

A revision of the genus (La Farge, 1998) revealed 112 species worldwide of which 77 are found in tropical Africa, most of them concentrated in SE Africa and especially the East African Islands. In contrast, there are only 14 species recorded for the Neotropics.

Plants small to large, in loose to dense tufts, dark green to yellowish-green. Stems erect to suberect, to 6 cm high, little branched; central strand absent. Leaves erect-spreading when wet, flexuose or falcate when dry, from ovate base lanceolate, subulate to setaceous, margins involute, entire to serrulate in the upper part, bordered from base to half or nearly the full length of the lamina; costa narrow, ending in apex; alar cells enlarged, coloured; basal laminal cells elongate to rectangular, smooth; upper laminal cells oblong-oval to quadrate, strongly papillose; marginal cells linear, hyaline, forming a border of several rows. Dioicous. Perichaetia terminal. Seta erect, elongate. Capsule straight, urn cylindrical; annulus absent. Operculum rostrate. Peristome teeth divided ca. 1/2, trabeculate below, papillose at tips. Calyptra cucullate. Spores smooth, weakly papillose or granulate.

Habitat. Epiphytic, also pendant from branches, in montane forests 800-2100 m.

Discussion. The genus is related to Dicranoloma, with which it shares the border of hyaline cells along leaf margins, but is distinguished by the short, pluripapillose upper laminal cells.

Literature. La Farge-England, C. 1998. The infrageneric phylogeny, classification, and phytogeography of Leucoloma (Dicranaceae, Bryopsida). Bryologist 101: 181-220.

Microcampylopus (Müll.Hal.) M.Fleisch.

A genus of three species, of which M. laevigatus (Thér.) Giese & J.-P.Frahm occurs in tropical Africa.

Plants 5-10 mm tall, gregarious or in loose tufts, yellow-green. Stems erect, mostly unbranched, loosely foliate. Leaves with broad sheathing base appressed to the stem and narrow, long erect-spreading or erect spreading subula, 2.5-4 mm long; margins entire (except at apex); costa long excurrent in the subula, ca. 1/3 width of leaf base; basal laminal cells enlarged, lanceolate, thin walled, upper laminal cells shorter and more incrassate; alar cells undifferentiated. Dioicous. Seta curved and twisted, to 6 mm long. Capsule ca. 1 mm long, two times longer than broad; deeply furrowed when dry and empty; annulus present. Operculum conic-rostrate, oblique. Peristome teeth vertically striate below, divided ca. 2/3 and perforate, rusty-red below, yellowish and papillose above. Calyptra cucullate, naked, base ± entire. Spores coarsely papillose, papillae large, 6-8 in diameter.

Habitat. On open loamy or lateritic soil, often along roadsides, from submontane to high montane areas (500 to 2500 m).

Discussion. The genus is vegetatively similar to small species of Anisothecium with broad sheathing leaf bases which are abruptly contracted into a long subula and can only be distinguished from the latter by the cygneous setae.

Literature. Giese, M. & Frahm, J.-P. 1985. A revision of Microcampylopus (C. Muell.) Fleisch. Lindbergia 11: 114-124 [illustration].

Paraleucobryum (Limpr.) Loeske

A holarctic genus with 3 species. Only P. longifolium ssp. brasiliense (Broth.) P.Müller & J.-P.Frahm occurs in the tropics; it is known from one collection in each of SE Brazil and D.R. Congo.

Plants medium sized, in dense tufts, greyish green. Stems erect, to 2.5 cm tall, little branched, radiculose below. Leaves long lanceolate, hamate, 8-13 mm long, subtubulose at tips, apex gradually acuminate; margins entire, serrate at tips; costa excurrent, filling 3/4 width of leaf base, smooth or slightly ridged at back, in transverse-section with a median and dorsal band of hyalocysts and a ventral and dorsal band of chlorocysts (the latter alternating with the hyalocysts), stereids absent; upper laminal cells narrow, long rectangular, basal cells larger, rectangular, weakly porose; alar cells well developed, cells inflated. Dioicous. Perichaetia terminal, leaves sheathing from a broad ovate base. Seta erect, 20-25 mm long, twisted. Capsule erect, urn cylindrical, 2-2.5 mm long; exothecial cells thick-walled; phaneroporous stomata at the base of the urn; annulus lacking. Operculum long rostrate. Peristome teeth divided to 1/2 or more, perforated below, striate below, papillose above. Calyptra cucullate, entire at base. Spores varying much in size, verrucose.

Habitat. Epiphytic, 3200 m.

Discussion. The genus resembles other genera such as Campylopus, Pilopogon, or Atractylocarpus in the very broad costa, but is distinguished by the absence of stereids in transverse section of the costa, the presence of chlorocysts between upper and lower hyalocysts, and elongate and narrow upper laminal cells. In appearance it looks like a species of Dicranum, and the shape of the capsule also resembles that of some Dicranum species.

Literature. Müller, P. & Frahm, J.-P. 1987. A review of the Paraleucobryoideae (Dicranaceae). Nova Hedwigia 45: 283-314. [keys, illustrations].

Pilopogon Brid.

Eight species worldwide, 7 of them in the neotropics, in Africa only P. africanus Broth.

Plants 1-4 cm tall, in loose to dense tufts, yellowish-green to golden-brown. Stems erect and slender, rarely branched; central strand present. Leaves erect to appressed when dry, slightly erect-spreading when wet, from a lanceolate or oblong base subulate, acute and serrate; margins entire; costa strong, short to long excurrent, filling 1/2 width of leaf base, in transverse-section with ventral and dorsal stereids and median guide cells, ribbed on back; upper laminal cells thick-walled, oval; basal laminal cells sharply delimited from the upper ones, long rectangular, thin-walled; alar cells weakly differentiated. Dioicous. Perichaetia terminal, leaves sheathing seta for 1/2 or more length of seta. Seta elongate, erect, 1-2 cm tall. Capsule erect, urn short cylindrical, stomata absent; annulus present. Operculum long rostrate, erect. Peristome teeth divided half of their length, striate below, papillose above. Calyptra cucullate, smooth and naked, base fringed with long hairs (ciliate). Spores slightly papillose.

Habitat. Exposed soil and rock, mainly in secondary habitats such as roadside banks, gravel and sand along roads and trails, 1500 – 4200 m.

Discussion. Vegetatively, the genus resembles Campylopus, but is distinguished by the straight seta, erect, cylindrical urn and long sheathing perichaetial leaves. The differentiation between these genera is straightforward, because Pilopogon species usually produce sporophytes abundantly.

Literature. Frahm, J.-P. 1983. A monograph of Pilopogon Brid. Lindbergia 9: 99-116 [keys, illustrations, maps].

Platyneurum (Cardot) Broth. in Engl. & Prantl

A monotypic genus with the only species Platyneurum praealtum (Mitt.) Ochyra & Bednarek-Ochyra. (Dicranum laticostatum Cardot). The African taxon was described by Magill (1981) from the Cape Province of South Africa as Chorisodontium falcatum but regarded as synonymous with Platyneurum laticostatum by Frahm (1989) and subsequently synonymised with P. praealtum by Ochyra (1997). Platyneurum differs from Chorisodontium by the absence of stereids in the transverse section of the costa and the back of the costa being coarsely mammillose.

Plants robust, greenish above, darker below, in dense mats. Stems erect, rarely branched, erect, tomentose with whitish or reddish tomentum, 3-7 cm tall. Leaves falcate secund when wet, flexuose or crowded when dry, 6-9 mm long, from oblong base narrowed into a narrow channelled subula; margin serrate in the upper part of the leaf; costa broad, filling 1/3 of leaf width at leaf base, filling the subula, strongly mammillose at back, the tips of mammillae thickened, in transverse section with a median band of deuter cells and 1-2 rows of thick walled dorsal and one row of substereidal ventral cells; laminal cells in the lower part of the leaf rectangular, thick walled, porose, shortly rectangular to oval or quadrate in the upper part; alar cells quadrate, incrassate, brownish or reddish. Sporophyte not known from South Africa.

Habitat. On rock.

Discussion. The only species of the genus is widely distributed in southern South America in the Nothofagus zone (Ochyra & Bednarek-Ochyra 1997) and has also been collected on Kerguelen Islands and South Georgia (Frahm 1989). It is easily distinguished by the broad costa filling the subula, which is mammillose at the back.

Literature. Frahm, J.-P. 1989. The genus Chorisodontium (Dicranaceae, Musci) in the Neotropics. Tropical Bryology 1:11-24. Magill, R.E. 1981. - see general refs. [illustration]. Ochyra, R. & Bednarek-Ochyra, H. 1997. The type specimen of Leptotrichum praealtum (Musci, Ditrichaceae). Fragmenta Floristica et Geobotanica 42: 567-570.

Pocsiella Bizot

A monotypic genus with only P. hydrogonioides endemic to Mt. Kilimanjaro.

Plants laxly caespitose, greenish above, chestnut brown below. Stems erect, 1.5-2 cm tall, rarely branched. Leaves distant, flexuose when dry, suberect when wet, from broad base ligulate, shortly acuminate, longly decurrent; costa strong, vanishing shortly below the apex; upper laminal cells irregular, isodiametric, 20 µm in diameter, basal laminal cells short rectangular. Dioicous (?). Perichaetia terminal, perichaetial leaves not differentiated. Seta erect, 7 mm long. Capsule erect, urn ovate, widest at mouth, 1.5 mm long. Operculum not known. Peristome teeth reddish, smooth, irregularly cleft. Calyptra not known. Spores smooth, 18-20 µm.

Habitat. On shady rocks in Erica arborea forest 2800-2900 m.

Discussion. The species is very conspicuous by the distant, longly decurrent leaves, which are compared by the author with Bryum weigelii. It resembles Oreoweisia, but differs by the non-papillose peristome teeth and the smooth laminal cells.

Literature. Bizot, M. 1980. Enumeratio muscorum novorum III. Cryptogamie, Bryologie. Lichénologie 1: 423-430. [illustration].

Pseudephemerum (Lindb.) I.Hagen

Only one species, P. nitidum (Hedw.) Reimers, worldwide including northern and Central Africa.

Plants small, yellow green. Stems erect, a few mm high. Leaves erect patent when dry, sinuose when wet, narrow lanceolate, longly acuminate, margins serrulate at tips; costa weak, vanishing before leaf apex; laminal cells rectangular, smooth, thin-walled, larger at leaf base. Synoicous. Perichaetia terminal, antheridia naked in the axils of the perichaetial leaves, perichaetial leaves similar to normal leaves. Seta minute, 1 mm long. Capsule immersed in upper stem leaves, oval, cleistocarpous. Operculum shortly obliquely rostrate. Calyptra small, cucullate. Spores papillose, 25-30 µm.

Habitat. On wet soil along banks of streams, in man-made habitats, in ditches, plantations, 1600–2900 m.

Discussion. The genus is distinguished by the small plants with cleistocarpous capsules, not unlike Archidium.

Sphaerothecium Hampe

A genus of three species worldwide, of which S. phascoides (Hampe) Hampe is only known from the vicinity of Bogotá, Colombia, S. reconditum Thwaites & Mitt. is known from Sri Lanka and S. subchlorophyllosum (Müll.Hal.) J.-P.Frahm is known from South Africa.

Plants small, to 15 mm high, in loose tufts, yellowish-green. Stems equally foliate, appressed when dry, erect patent when moist; central strand present. Leaves from an ovate base narrowly lanceolate, to 4 mm long, ending in a channelled subulate apex; margins entire; costa excurrent in a short hyaline hairpoint, filling 3/4 of leaf base, in transverse section with ventral and dorsal stereid bands and a median band of guide cells, ridged or shortly lamellose at back; upper laminal cells oval,, incrassate, basal laminal cells rectangular, incrassate, alar cells weakly differentiated. Dioicous. Perichaetia terminal. Seta 4-5 mm long, curved, yellowish-brown. Capsule immersed in upper leaves, urn subglobose to ovoid, 1 mm long; annulus large, reddish-brown, dehiscent. Operculum obliquely short-rostrate. Peristome teeth reduced, basal membrane low, equal to or just exceeding mouth. Calyptra cucullate, naked and smooth, base ciliate. Spores finely papillose, 21 µm in diameter.

Habitat. On open soil in exposed sites; known only from a few collections in South Africa.

Discussion. Vegetatively Sphaerothecium resembles a small Campylopus, but differs from the latter by immersed sporophytes, subglobose capsules, enlarged annulus, short peristome, and larger spores. Included in Magill (1981) as Campylopus subchlorophyllosus.

Literature. Frahm, J.-P. 1986. A review of Sphaerothecium Hampe. The Bryologist 89: 152-154. [illustration]. Magill, R.E. 1981. - see general refs. [description, illustration].

Symblepharis Mont.

Excluded: the only record for Africa was found not to belong to this genus.

Literature. Dixon, H.N. 1933. Mosses collected on Mt. Cameroon by Miss Steele. Annales Bryologici 6: 20-30. [description, but no illustration].

accepted 17.04.2000