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ORTHOTRICHACEAE

(J. Wilbraham)

Plants small to robust, tufted or forming mats. Corticolous, saxicolous or rarely terricolous. Stems erect or creeping, variously branched, in section with central strand lacking. Leaves erect-appressed or variously twisted when dry, spreading to squarrose when wet, variously ovate, oblong or lanceolate, occasionally undulate or rugose, unistratose, bistratose or rarely multistratose; apex variable, rarely fragile; margins generally entire but can be toothed; costa always present, single, percurrent to excurrent; upper laminal cells usually small, rounded hexagonal or rarely short rectangular, flat to bulging, incrassate, smooth, unipapillose to pluripapillose; basal laminal cells quadrate, rectangular or linear, incrassate, smooth, papillose or tuberculate, alar cells not differentiated. Gemmae sometimes present. Dioicous or autoicous. Perigonia lateral or terminal, bud-like, leaves strongly differentiated, short, concave. Perichaetia terminal on erect branches, leaves differentiated, oblong lanceolate to linear lanceolate. Seta short to elongate, usually smooth, often twisted. Capsules immersed to exserted, erect, ovoid to cylindric, smooth or ribbed, stomata superficial or immersed. Operculum conic rostrate. Peristome single, double, reduced or absent, exostome of 16 teeth, free or fused into 8 pairs or forming a continuous membrane, endostome often reduced, smooth or papillose. Calyptra mitrate, campanulate or cucullate, often relatively large, smooth or plicate, lobate or lacerate, naked or hairy. Spores spherical, smooth or papillose, isosporous or anisosporous.

Discussion. The Orthotrichaceae are a large and diverse family of approximately 600 species which are distributed among 27 genera (Goffinet & Vitt 1998). Members of the family are predominately xerophytic and are usually found as epiphytes or growing on rocks. The Orthotrichaceae have a reduced and highly modified diplolepidous peristome that is variously altered across the family and often appears single due to the suppression of either the exostome or the endostome. Characteristics for the family are the small, isodiametric upper laminal cells which are often ornamented with papillae, the basal cells are usually elongated with the alar cells typically undifferentiated, the central strand of the stem is absent, the capsules are often ribbed and the calyptra is often relatively large, either mitrate, campanulate or cucullate.

The Orthotrichaceae contains the two sub-families Orthotrichoideae and Macromitrioideae, which are treated at family level by some authors (Churchill & Linares 1995).

Literature. Churchill, S.P., Linares, C.E.L. 1995. Prodromus Bryologiae Novo-Granatensis. Introduction a la Flora de Musgos de Colombia. Parte 2. Bibliotheca ‘Jose Jeronimo Triana’ 12: 455–924. Goffinet, B., Vitt, D.H. 1998. Revised generic classification of the Orthotrichaceae based on a molecular phylogeny and comparative morphology. pp. 143–159 in Bryology for the twenty-first century. Eds. Bates, J.W., Ashton, N.W., Duckett, J.C. British Bryological Society. Goffinet, B., Shaw, A.J., Cox, C. J., Wickett, N.J., Boles, S.B. 2004. Phylogenetic inferences in the Orthotrichoideae (Orthotrichaceae, Bryophyta) based on variation in four loci from all genomes. pp. 270–289 in Molecular systematics of Bryophytes. Eds. Goffinet, B., Hollowell, V., Magill, R. Missouri Botanical Garden Press. Vitt, D.H. 1982. The genera of Orthotrichaceae. In P. Geissler & S. W. Greene (eds.), Bryophyte Taxonomy. Beihefte zur Nova Hedwigia 71: 261–268.


1. Plants in loose mats; primary stem prostrate with many erect to ascending branches; sporophytes usually produced on secondary branches (Subfamily Macromitrioideae) 2
1. Plants tufted or in cushions; primary stem erect, simple or sparsely branched; sporophytes produced on primary branches (Subfamily Orthotrichoideae)
7
2. Leaf apex obtuse, margin papillose-crenulate, papillae large, branched; setae twisted clockwise viewed from above Bryomaltaea
2. Leaf apex acute, margin not papillose-crenulate, papillae if present small conical; setae twisted anticlockwise viewed from above 3

3. Dry leaves twisted-contorted, linear lanceolate with an ovate base, leaf base with margin of cells differentiated from inner cells

Ulota
3. Dry leaves crispate to flexuose, base not ovate, without distinct margin of differentiated cells 4
4. Gemmae frequent, on stems or rhizoids; capsule stomata superficial; peristome absent, single or double; calyptra cucullate, rarely hairy 5

4. Gemmae occasional, on leaf lamina or rarely on rhizoids; capsule stomata superficial or immersed; peristome double or rarely single; calyptra mitrate, hairy

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5. Upper laminal cells papillose; peristome double or single, often rudimentary
Zygodon

5. Upper laminal cells smooth; peristome double

Codonoblepharon
6. Branch leaves contorted when dry; perichaetial leaves highly differentiated, hyaline below and enveloping the capsule Stoneobryum
6. Branch leaves erect appressed when dry, rarely flexuose; perichaetial leaves not, or only slightly, differentiated, mostly chlorophyllose below Orthotrichum
7. Basal laminal cells elongate, usually linear-rectangular, upper laminal cells short and rounded
8
7. Basal laminal cells short and rounded, similar to but somewhat larger than upper laminal cells 10
8. Leaves with a basal margin of elongate cells extending 1/4-1/5 lamina length, inner basal cells quadrate-rounded Groutiella
8. Leaves with basal marginal cells similar to inner cells, without a distinct margin 9
9. Mid-leaf cells irregularly oriented or in vertical rows; calyptra mitrate, often plicate, deeply lobed, smooth or hairy; peristome lacking, single or double
Macromitrium subgenus Macromitrium
9. Mid-leaf cells somewhat rhomboid, in diagonal rows; calyptra campanulate, not plicate; peristome double, well developed Schlotheimia
10. Upper laminal cells strongly papillose with tall conical papillae; cells of leaf decurrency large and inflated Cardotiella

10. Upper laminal cells smooth to bulging or weakly papillose; cells of leaf decurrency not inflated

11
11. Branch leaves contorted when dry, with adventitious filaments from basal cells; seta papillose; capsule urn-like Macromitrium subgenus Cometium
11. Branch leaves erect appressed to loosely twisted when dry, lacking adventitious filaments from basal cells; seta smooth; capsule cylindrical 12
12. Branch leaves with mostly acute apices, upper laminal cells smooth or unipapillose Macrocoma
12. Branch leaves with mostly rounded, obtuse apices, upper laminal cells unipapillose or with 2 to 3 papillae per cell Leiomitrium

 

Bryomaltaea Goffinet

A monospecific genus with B. obtusifolia recorded in Africa from Democratic Republic of Congo (former Zaire).

Plants small, dark green above, red-brown below, forming dense tufts. Stems frequently branched, 5–10 mm tall, rhizoids well developed, red-brown. Leaves erect-appressed when dry, erecto-patent when moist, ovate-oblong with obtuse apex, slightly concave, 0.5–0.9 mm long, leaf base not decurrent; margin papillose-crenulate, lower two thirds of leaf often recurved; costa broad, ending below leaf apex, costal guide cells ventral with a few thick walled cells below; upper lamina cells irregular rounded, thick walled, with large, branched papillae; basal laminal cells weakly differentiated, slightly papillose, larger, thinner walled. Gemmae often present, 3–6 cells long, ellipsoid, green. Autoicous. Perigonia bud like, leaves broadly ovate in lower half, upper half lingulate. Perichaetial leaves more oblong and slightly longer than stem leaves. Seta 3–4 mm long, twisted clockwise when viewed from above. Capsule ovoid to cylindrical, < 1 mm, with eight wide ridges. Calyptra cucullate, smooth. Peristome double, exostome teeth 16 united into 8 teeth pairs. Spores densely papillose.


Bryomaltaea obtusifolia
(Hook.) Goffinet. A: Habit (dry). B: Capsule. C: Branch leaves D: Upper laminal cells. E: Basal laminal cells. F: Gemma. Drawn from Touw 9800, Thailand (BM).

Habitat. Epiphytic, or rarely on rocks. Somewhat temperate in distribution and found growing at higher altitudes in the tropics.

Discussion. This distinctive plant is characterised by the small leaves with a broadly obtuse apex and the large, branched papillae of the laminal cells. Bryomaltaea is widely distributed from Mexico, Central and South America, Australia and Asia, though only one collection has been recorded in the literature from Africa (Leroy 1947).

Literature: Goffinet, B, Vitt, D.H. 1998. Revised generic classification of the Orthotrichaceae based on a molecular phylogeny and comparative morphology. pp. 143–159 in Bates, J.W., Ashton, N.W., Duckett, J.C. 1998. Leroy, V. 1947. Récoltes Bryologiques au Congo Belge et au Ruanda-Urundi. Bulletin Jardin Botanique Bruxelles 18: 155–206.


Cardotiella Vitt

A genus of six species, four of which are endemic to the East African islands of Madagascar, Réunion and Mauritius, one is endemic to South Africa and one species is known from the Neotropics.

Plants medium sized, forming coarse intertwining mats, green to yellowish or brownish green. Stems creeping, tomentose, branches stiff, ascending and curved, rhizoids numerous on older stems and occasionally at leaf bases. Branch leaves crowded, erect-appressed, somewhat secund when dry or flexuose, spreading when wet, in 4 or 5 rows, often rugose, ovate-lanceolate, to 2 mm long, apices short acuminate, often bluntly so, long decurrent; margins entire to dentate by projecting cell papillae, recurved below; costa single, strong below, ending below apex, upper laminal cells quadrate-rounded, unipapillose or rarely smooth, incrassate; basal cells similar; decurrency cells inflated, often tuberculate, hyaline. Stem leaves smaller, lanceolate. Sporophytes rare. Dioicous. Perigonia lateral, bud like, leaves broadly ovate-apiculate. Perichaetia terminal on branches, leaves ovate-subulate to oblong-subulate. Seta short, smooth. Peristome double, 16 exostome teeth, partly fused to form 8 pairs, somewhat papillose, endostome segments 8-16, alternating with teeth. Capsule exserted, erect, elliptic, 8-ribbed; stomata superficial. Operculum conic-rostrate. Calyptra mitrate-campanulate, lobed at base, smooth to sparsely hairy. Spores minutely papillose.



Cardotiella secunda
(Müll.Hal) Vitt. A: Habit (dry). B: Branch leaves. C: Stem leaves. D: Upper laminal cells. E: Basal laminal cells. Drawn from Eddy & Sims 7139, South Africa (BM).

Habitat. The South African species Cardotiella secunda is known to occur at low altitudes (20–760m), growing on trees or rarely on rocks, in forests of the Fynbos and Savannah (van Rooy & van Wijk 1992). Ecological information on this genus in the East African Islands is somewhat limited.

Discussion. Cardotiella is distinguished by the creeping stems, branch leaves short ovate-lanceolate, laminal cells quadrate-rounded, often unipapillose and with long decurrent leaf bases of inflated, tuberculate cells, the well-developed peristome and the large mitrate, basally lobed calyptra.

Literature. Goffinet, B. 1996. Cardotiella elimbata (Thér.) Goffinet comb. nov. and C. appendiculata new to Mauritius (Musci, Orthotrichaceae). Bryologist 99: 390–396. Magill, R.E., Van Rooy, J. 1998. Flora of Southern Africa. Bryophyta. Part 1. Mosses. Fasc. III. Erpodiaceae – Hookeriaceae. In: Leistner OA, Flora of Southern Africa. Republic of South Africa: Botanical Research Institute, Department of Agriculture and Fisheries. Van Rooy, J., Van Wijk, A.E. 1992. A conspectus of the Subfamily Macromitrioideae (Bryopsida: Orthotrichaceae) in Southern Africa. Bryologist 95(2): 205–215. Vitt, D.H. 1981. The genera Leiomitrium and Cardotiella gen. nov. (Orthotrichaceae). Journal of the Hattori Botanical Laboratory 49: 93–113.


Codonoblepharon Schwägr.

A genus of eight species, three of which are known from Africa.

Plants small to medium sized, occasionally robust, forming rather dense tufts, green to reddish or golden-brown. Stems mostly erect, occasionally subascending, simple or sparsely branched, rhizoids red-brown. Leaves erect to suberect, contorted or slightly crispate when dry, spreading to squarrose-recurved when wet, oblong, elliptical to oblong-lanceolate or -linear, 0.8–2.7 mm long, apex acute to acuminate to apiculate, margins plane or recurved below, entire to distally toothed, often sharply so, not decurrent; costa single, subpercurrent to shortly excurrent; upper laminal cells smooth, quadrate- to hexagonal-rounded; basal laminal cells larger, mostly rectangular, firm-walled or lax and mostly hyaline. Gemmae frequently produced, fusiform. Autoicous, dioicous or synoicous. Perichaetia terminal, leaves little differentiated or much longer than branch leaves. Seta smooth, 2.5–6 mm long, twisted anticlockwise when viewed from above. Capsule erect, urn subcylindrical to narrowly pyriform, 8-ribbed, neck short tapered; stomata superficial at base; annulus present and persistent. Operculum conic-rostrate. Peristome double, consisting of 16 paired and reflexed exostome teeth with erect endostomes. Calyptra cucullate, naked or sparsely hairy. Spores smooth.


Codonoblepharon microtheca
(Dixon ex Malta) Matcham & O'Shea. A: Habit (dry). B: Capsule.
C:
Branch leaves. D: Upper laminal cells. E: Basal laminal cells. F: Gemmae. Drawn from Eddy & Sims, 7104, South Africa (BM).

Habitat. Epiphytic on trees or growing on rocks, often in montane habitats.

Discussion. The genus Codonoblepharon was resurrected by Goffinet & Vitt (1998) and incorporates the smooth celled members of Zygodon section Bryoides. Codonoblepharon is distinguished from Zygodon by its smooth laminal cells, double peristome and smooth spores. It has a widespread, scattered distribution, with C. microtheca being the most common member of this genus in Africa.

Literature. Goffinet, B., Vitt, D.H. 1998. Revised generic classification of the Orthotrichaceae based on a molecular phylogeny and comparative morphology. pp. 143–159 in Bryology for the twenty-first century. Eds. Bates, J. W., Ashton, N. W., Duckett, J. C. British Bryological Society. Matcham, H.W., O'Shea, B.J. 2005. A review of the genus Codonoblepharon Schwägr. (Bryopsida: Orthotrichaceae). Journal of Bryology 27: 129–135


Groutiella Steere

A genus primarily distributed in the Neotropics with only two species recorded for Africa.

Plants medium sized, forming dense mats, brownish green to dull green. Primary stems creeping with numerous short erect branches, densely tomentose. Branch leaves contorted when dry and irregularly twisted around the stem, spreading when wet, oblong-ligulate to oblong-lanceolate, smooth, rugose or undulate, apex obtuse, mucronate or acute to acuminate, or ending in a fragile, deciduous subula; margins plane to undulate, entire; costa single, ending below apex to shortly excurrent; upper laminal cells quadrate-rounded to suboval, smooth or mammillate-bulging, basal laminal cells with a distinct margin of elongated cells, inner basal cells oblong to short rectangular-rounded, often tuberculate. Stem leaves differentiated in shape and size from branch leaves. Sporophytes rare in Africa. Dioicous. Perichaetia terminal on branches, leaves usually undifferentiated. Seta elongate, stout, smooth. Capsule erect, urn ovoid or obloid elongate, neck short; stomata at urn base, superficial. Operculum long-rostrate. Peristome reduced to a low membrane and papillose, or appearing absent. Calyptra mitrate, naked, plicate or smooth. Spores isosporous or anisosporous, smooth to densely papillose.


Groutiella laxotorquata
(Müll.Hal. ex Besch.) Wijk & Margad. A, F: Habit (dry). B: Branch leaves.
C:
Stem leaves. D: Upper laminal cells. E: Basal laminal cells. Drawn from O’Shea U2672a, Uganda (BM).

Habitat. On tree trunks, logs, and occasionally on rocks; wet lowland to low montane forests, 1000–2040 m.

Discussion. The elongate laminal cells bordering the lower leaf margins are diagnostic for separating Groutiella from other genera in the Macromitrium complex. Groutiella laxotorquata Besch. is the widespread species of Groutiella found in Africa.

Literature. Allen, B. 2002. The Moss flora of Central America, Part 2. Encalyptaceae –Orthotrichaceae. St Louis: Missouri Botanic Garden [Generic description and illustrations]. Wilbraham, J. 2008. Bryophyte Flora of Uganda. 8. Orthotrichaceae, Part 1. Macromitrioideae. Journal of Bryology 30: 201–207.


Leiomitrium Mitt.

Consisting of the single species Leiomitrium plicatum, which is restricted to the Mascarene Islands.

Plants slender, forming in tangled mats. Stems creeping with numerous branches, erect curved to horizontally spreading. Branch leaves imbricate, loosely erect to flexuose erect, lanceolate to broadly oblong, obtuse, 0.8–1.5 mm long, occasionally with small mucro, upper laminal cells bulging, unipapillose or with 2–3 papillae per cell, simple or sometimes forked, basal cells rounded, bulging, smooth or unipapillose, costa broad, ending below apex. Stem leaves loosely erect to flexuose erect, ovate lanceolate, shortly acuminate to acute, upper laminal cells bulging, smooth, unipapillose or rarely 2–3 papillae per cell, papillae conical or forked, basal cells similar, bulging smooth, costa ending below apex. Dioicous. Perichaetial leaves similar to vegetative leaves. Seta stout, erect, with very long ochrea. Capsule exserted, cylindric, strongly eight ribbed, stomata in lower part of capsule, superficial. Peristome diplolepidous, exostome of 8 teeth, often partially divided into 16, reflexed teeth, endostome of 8–16 short segments. Calyptra mitrate, plicate, hairy. Spores papillose.


Leiomitrium plicatum
(P.Beauv.) Mitt. A: Habit (dry). B: Branch leaves. C: Stem leaves. D: Upper laminal cells. E: Basal laminal cells. Drawn from Balfour s.n., Rodriguez (BM).

Habitat. Limited ecological information available.

Discussion. Leiomitrium is closely related to Macrocoma, from which it is distinguished by the rounded obtuse branch leaves, and the papillose upper laminal cells. N.B. the shape of the branch leaves can vary greatly even on the same shoot.

Literature. Vitt, D.H. 1981. The Genera Leiomitrium and Cardotiella Gen. Nov. (Orthotrichaceae). Journal of the Hattori Botanical Laboratory 49: 93–113.


Macrocoma (Hornsch. ex Müll.Hal.) Grout

A genus of eleven species, five of which are found in Africa. Rather widespread in the subtropics and tropics, extending into the temperate regions of both hemispheres.

Plants small to medium-sized, forming mats, dark green to golden-brown. Stems creeping, branches erect, slender, irregularly branched. Branch leaves closely appressed or occasionally slightly flexuose when dry, not contorted, erect-spreading to squarrose when wet, lanceolate to ovate-lanceolate, unistratose or bistratose; apex narrowly obtuse, acute to acuminate; margins plane often recurved below, entire to crenulate; costa single, prominent, ending below apex; upper laminal cells rounded, quadrate, flat or bulging; basal laminal cells rounded, short rectangular to elliptic, bulging, often with tuberculae. Stem leaves similar to branch leaves or differentiated. Autoicous or dioicous. Perigonia terminal or lateral, leaves broadly ovate apiculate. Perichaetia terminal on short branches, leaves usually oblong lanceolate. Seta elongate, to 8 mm long, smooth. Capsule erect, urn cylindrical, smooth or lightly 8-ribbed; stomata at urn base, superficial. Operculum conic short to long-rostrate. Peristome double, single or absent, exostome of 16 teeth, usually reduced, endostome of 16 segments, usually forming a low membrane. Calyptra large, mitrate, smooth or weakly plicate, naked to densely hairy. Spores papillose, isosporous.


Macrocoma tenuis
ssp. tenuis (Hook. & Grev.) Vitt. A, H: Habit (dry). B: Capsule with calyptra. C: Capsule. D: Branch leaves. E: Stem leaves. F: Upper laminal cells. G: Basal laminal cells. Drawn from Miehe U31-10750-05, Uganda (BM).

Habitat. Epiphytic, on branches and trunks of shrubs and trees, rarely on rocks. Macrocoma typically occurs in savannas, woodlands and forests, 900–4000 m.

Discussion. The genus is distinguished by the creeping habit with slender branches, costa ending well below apex, upper and lower laminal cells similar, smooth to weakly unipapillose, the mostly rudimentary peristome and the large mitrate calyptra.

Literature. Magill, R.E., Vitt, D.H. 1981. The phytogeography and ecology of Macrocoma (Orthotrichaceae, Musci) in Africa. Bothalia 13: 463–466. Van Rooy, J., Van Wijk, A.E. 1992. A conspectus of the Subfamily Macromitrioideae (Bryopsida: Orthotrichaceae) in Southern Africa. Bryologist 95(2): 205–215. Vitt, D.H. 1973. A revisionary study of the genus Macrocoma. Revue Bryologique et Lichénologique 34: 205–220 [keys, illustrations]. Vitt, D.H. 1980. The nomenclature and taxonomy of Macrocoma lycopodioides (Schwägr.) Vitt. Journal of Bryology 11: 219–229 [includes key to African species of Macrocoma]. Vitt, D.H. 1980a[1981]. The genus Macrocoma I. Typification of names and taxonomy of the species. Bryologist 83: 405–436. Vitt, D.H. 1980b[1981]. The genus Macrocoma II. Geographical variation in the Macrocoma tenue - M. sullivantii species complex. Bryologist 83: 437–450. Wilbraham J. 2007. Taxonomic notes on the pantropical genera Macromitrium and Macrocoma. Journal of Bryology 29: 54–59..



Macromitrium Brid.

A large genus of about 250 species. Approximately 54 species are recorded for Africa, though it is possible that only half of these are justified names. Macromitrium is widely distributed in the tropics and Southern Hemisphere.

Plants mostly medium-sized to large and robust, occasionally small, forming loose to dense mats or tufts, dark green to reddish-brown or golden. Stems short to long creeping, leaves often inconspicuous and hidden in dense tomentum, branches short to long erect. Branch leaves variously contorted, usually crispate and often spirally twisted, erect-spreading to spreading when wet, linear-lanceolate, oblong-lanceolate to lingulate, 1.5–4.8 mm long, apex obtuse or acute to short or long acuminate, rarely fragile; margins plane to recurved below, smooth to dentate at apex; costa single, subpercurrent to shortly excurrent; upper laminal cells thick-walled, median cells oval, rounded-subquadrate or elongate (e.g., in apices), smooth, bulging mammillose or papillose; basal cells often elongate and narrow, often tuberculate or papillose, occasionally smooth, often porose. Stem leaves similar to branch leaves or differentiated. Dioicous or autoicous, dwarf males occasional. Perichaetia terminal on stems or appearing on terminal branches, leaves differentiated or not. Seta elongate, erect to slightly flexuose, smooth or roughened. Capsule exserted, erect, urn subglobose to ovoid-cylindrical, smooth to furrowed or ribbed; stomata at base, superficial. Operculum short- to long-rostrate, erect or oblique. Peristome often rudimentary, absent, single or double, exostome often truncate and papillose; endostome membranous. Calyptra large, mitrate, base often lacerate, plicate, naked or sparsely to densely hairy. Spores papillose, isosporous or anisosporous.


Macromitrium sulcatum
(Hook.) Brid. A: Habit (dry). B: Capsule with calyptra. C: Branch leaves
D:
Stem leaves. E: Upper laminal cells. F: Basal laminal cells. Drawn from O'Shea U5447a, Uganda (BM).

Habitat. Epiphytic, on trunks and branches of trees and shrubs, frequent in the canopy, occasionally on rocks; wet lowland forest to more montane forests, 500–3000 m.

Discussion. Macromitrium is distinguished by the creeping primary stem with numerous erect bushy branches, branch leaves variously contorted when dry, elongate basal cells that are often tuberculate, the large mitrate calyptra and reduced peristome. Macromitrium sub-genus Cometium, represented in Africa by M. orthostichum, has many features which differentiate it from other members of Macromitrium, such as the slender filiform habit and branch leaves with short basal cells. Macromitrium sulcatum is the most commonly found member of the genus in Africa. A critical revision of the African Macromitrium is urgently needed and will greatly reduce the number of currently accepted names.

Literature. Magill, R.E., Van Rooy, J. 1998. Flora of Southern Africa. Bryophyta. Part 1. Mosses. Fasc. III. Erpodiaceae – Hookeriaceae. In: Leistner OA, Flora of Southern Africa. Republic of South Africa: Botanical Research Institute, Department of Agriculture and Fisheries. Van Rooy, J, Van Wijk, A.E. 1992. A conspectus of the subfamily Macromitrioideae (Bryopsida: Orthotrichaceae) in Southern Africa. Bryologist 95(2): 205–215. Van Rooy J. 1990. A new species and a new record of Macromitrium (Orthotrichaceae) from southern Africa: M. lebomboense sp. nov. and M. richardii Schwägr. Journal of Bryology 16: 209–214. Wilbraham J. 2007. Taxonomic notes on the pantropical genera Macromitrium and Macrocoma. Journal of Bryology 29: 54–59.


Orthotrichum Hedw.

A widely distributed genus of 116 species, with 15 species known from Africa.

Plants mostly medium sized, forming loose to dense tufts, olive- or yellowish-green, brown below. Stems erect, sparsely branched, radiculose below. Leaves appressed to erect, occasionally flexuose when dry, erect-spreading to spreading when wet, narrowly lanceolate to oblong- or ovate-lanceolate, 0.8–5.5 mm long, often keeled distally, acuminate to acute or rounded, rarely apiculate, base undifferentiated or short decurrent; margins plane to more often recurved, occasionally undulate or flexuose, generally entire or denticulate at apex; costa single, usually strong, ending below apex, rarely excurrent; upper laminal cells mostly thick-walled, apical cells oval to elongate; median cells isodiametric to oblong, entire to nodose, papillose, papillae simple or branched; basal cells short to long rectangular, smooth, thin- to thick-walled, entire, nodose or porose; alar cells rarely differentiated, subquadrate-rounded. Gemmae occasionally present on leaves, short cylindrical. Autoicous. Perichaetia terminal; leaves not, or only slightly, differentiated. Seta short to elongate, 0.3–9.0 mm long, smooth, often twisted anticlockwise viewed from above. Capsule immersed to somewhat long exserted, erect, urn oblong-ovoid cylindrical, often ribbed; stomata on lower half of urn, immersed or superficial. Operculum plano-convex, apiculate. Peristome double (rarely reduced and single), erect or reflexed when dry, exostome teeth 8 pairs, often splitting into 16, papillose, rarely smooth; endostome often reduced, 8 or 16 segments, smooth, papillose or striate. Calyptra mitrate, mostly plicate, rarely smooth, sparsely to densely hairy, or surface roughened, base entire or sometimes split into separate lobes. Spores papillose.


Orthotrichum arborescens
Thér. & Naveau. A: Habit (dry). B: Capsule with calyptra. C: Branch leaves. D: Superficial stomata in capsule wall. E: Upper laminal cells. F: Basal laminal cells. Drawn from Miehe U2610742-02, Kenya (BM).

Habitat. Mostly epiphytic on branches and trunks, occasionally on rocks; at lower latitudes mostly 1000–5000 m.

Discussion. The genus is characterized by the erect stems with typically erect - appressed leaves, capsules often ribbed, immersed to shortly exserted, stomata immersed or superficial and the often plicate, mitrate, hairy calyptra. Sporophytes are often essential for the identification of Orthotrichum species. An excellent treatment of the genus in Africa is given by Lewinsky (1978).

Literature. Lewinsky, J. 1978. The genus Orthotrichum Hedw. (Musci) in Africa south of the tropic of Cancer. Botanisk Tidsskrift 72: 61–85 [Keys, descriptions and illustrations]. Lewinsky, J., Van Rooy, J. 1990. New species and a new record of Orthotrichum from southern Africa: O. incurvomarginatum sp. nov., O. armatum sp. nov., O. oreophilum sp. nov. and O. firmum Vent. Journal of Bryology 16: 67–78. Lewinsky, J. 1993. A synopsis of the genus Orthotrichum Hedw. (Musci, Orthotrichaceae). Bryobrothera 2: 1–59.


Schlotheimia Brid.

The genus is characterized by the erect stems with typically erect-appressed leaves, capsules often ribbed, immersed to shortly exserted, stomata immersed or superficial and the often plicate, mitrate, hairy calyptra. Sporophytes are often essential for the identification of Orthotrichum species. An excellent treatment of the genus in Africa is given by Lewinsky (1978)

Plants medium sized to large, forming dense mats, greenish brown to rusty brown. Stems creeping, with erect bushy branches. Branch leaves appressed and often spirally coiled around the stem when dry, erect-spreading when wet, ovate-oblong, ligulate, or oblong-acuminate, unistratose, often rugose; apex rounded-obtuse, acute, cuspidate or mucronate; margins plane or recurved below, entire; costa strong, often channelled, ending below apex to shortly excurrent; upper laminal cells rounded, incrassate, smooth, median cells often rhomboidal; basal laminal cells homogenous, narrowly rectangular, incrassate, pitted. Stem leaves usually smaller than branch leaves, ovate-lanceolate, costa percurrent, shortly excurrent or aristate. Dioicous, often producing dwarf male plants. Perigonia terminal. Perichaetia terminal on short lateral branches, leaves often differentiated. Seta short to elongate, 2–12 mm long, smooth. Capsule exserted, erect, ovoid to ovoid-cylindrical, 1.5–3.0 mm long; stomata at capsule base, superficial, or occasionally appearing immersed. Operculum short- to long-rostrate. Peristome well developed, double, exostome of 16 teeth, reflexed when dry, papillose, endostome segments alternating with exostome teeth, shorter than exostome. Calyptra large, campanulate, covering whole of capsule, naked, lobed below. Spores papillose, isosporous or anisosporous.


Schlotheimia ferruginea
(Bruch ex Hook. & Grev.) Brid. A: Habit (dry). B: Capsule with calyptra.
C:
Branch leaves D: Stem leaves. E: Upper laminal cells. F: Mid-laminal cells. G: Basal laminal cells. Drawn from O’Shea U2882a, Uganda, (BM).

Habitat. Epiphytic on tree trunks and branches, also on logs and rocks. Occurs in semi-dry to more commonly in wet lowland to mid montane forests, 900–2600 m.

Discussion. The genus is characterised by crowded rugose branch leaves that are twisted to spirally twisted around the branch when dry, the large, naked, basally lobed, bell shaped calyptra and the well developed double peristome. Examination of the stem leaves, with regard to the excurrency of the costa, is important for determination of African specimens. Schlotheimia is in need of critical study in Africa, particularly on the East African Islands where a large number of names have been described.

Literature. Magill, R.E., Van Rooy, J. 1998. Flora of Southern Africa. Bryophyta. Part 1. Mosses. Fasc. III. Erpodiaceae – Hookeriaceae. In: Leistner OA, Flora of Southern Africa. Republic of South Africa: Botanical Research Institute, Department of Agriculture and Fisheries. Van Rooy. J., Van Wijk, A.E. 1992. A conspectus of the subfamily Macromitrioideae (Bryopsida: Orthotrichaceae) in Southern Africa. Bryologist 95(2): 205–215. Wilbraham, J. 2008. New synonymy and typification in African Schlotheimia (Orthotrichaceae). Journal of Bryology 30: 196–200.


Stoneobryum D.H.Norris & H.Rob.

Two species have been placed in this genus; S. mirum is known only from South Africa and S.bunyaense is found in Australia.

Plants small, tufted cushions, up to 15 mm tall. Stems tomentose below, rhizoids red-brown. Leaves larger above, 2.2–3.0 mm long, sheathing base, crispate when dry, oblong to oblong-lingulate; costa section scarcely differentiated; upper laminal cells rounded-hexagonal, incrassate, smooth to slightly mammillose; basal cells rectangular, thin walled to incrassate, smooth, rarely papillose. Dioicous. Perigonia lateral, gemmate. Perichaetia terminal, leaves highly differentiated, hyaline, erect, enveloping capsule. Seta very short. Capsule immersed, ribbed, stomata immersed. Peristome double, exostome teeth in 8 pairs, endostome alternating with teeth pairs. Calyptra small, mitrate, hairy. Spores round, minutely papillose.

[Stoneobryum mirum (Lewinsky) D.H. Norris & H. Rob. - Waiting for specimen….]

Habitat. Epiphytic.

Discussion. Stoneobryum is distinguished by the highly differentiated, hyaline perichaetial leaves enveloping the capsule. It is considered close to Orthotrichum based on the immersed stomata, though the crispate leaves of Stoneobryum mirum give the plant a superficially Ulota-like appearance.

Literature. Magill, R.E., Van Rooy, J. 1998.Flora of Southern Africa. Bryophyta. Part 1. Mosses. Fasc. III. Erpodiaceae – Hookeriaceae. In: Leistner OA, Flora of Southern Africa. Republic of South Africa: Botanical Research Institute, Department of Agriculture and Fisheries. Norris, D.H, Robinson, H. 1981. Stoneobryum, a new genus of Orthotrichaceae from South Africa and southern Queensland. Bryologist 84: 95–99.


Ulota D.Mohr.

A genus of 50–60 species primarily distributed in temperate regions, with only 4 species recorded from sub-Saharan Africa.

Plants small, forming cushions. Stems simple, erect to ascending. Leaves crisped when dry, erect spreading when wet, linear-lanceolate above an oval or ovate base, ca 1.5–3.0 mm long, apex acute to acuminate, base sheathing; costa ending below apex; upper laminal cells irregularly rounded, smooth to weakly papillose; basal cells rectangular or rhomboidal, marginal basal cells differentiated from inner cells, quadrate, hyaline, thick walled. Autoicous. Perigonia terminal on short branches. Perichaetia terminal, leaves weakly differentiated. Seta smooth, twisted anticlockwise viewed from above. Capsule oval, contracted below mouth when dry, 8-ribbed, stomata superficial. Operculum conic rostrate. Peristome double, exostome of 16 teeth in 8 pairs, endostome segments alternate with exostome teeth. Calyptra mitrate, hairy. Spores granulose, isosporous.


Ulota ecklonii
(Hornsch.) A.Jaeger. A: Habit (dry). B: Capsule with calyptra. C: Branch leaves.
D: Upper laminal cells. E: Basal laminal cells. Drawn from O’Shea 99A31, South Africa (Priv. Herb. O'Shea).

Habitat. Epiphytic, saxicolous or rarely terricolous, mostly distributed in moist temperate forest and recorded up to 4800 m a.s.l. in Africa.

Discussion. The genus is distinguished by the twisted-contorted leaves which are linear lanceolate with an ovate base, rounded upper laminal cells, capsule ribbed with a double peristome and hairy calyptra.

Literature. Magill, R.E., Van Rooy, J. 1998. Orthotrichaceae, Ulota: pp 504-505. Flora of Southern Africa. Bryophyta. Part 1. Mosses. Fasc. III. Erpodiaceae – Hookeriaceae. In: Leistner, O.A., Flora of Southern Africa. Republic of South Africa: Botanical Research Institute, Department of Agriculture and Fisheries.


Zygodon Hook. & Taylor

A genus of 50 or more species primarily distributed in the tropics and subtropics, extending into the temperate regions of both hemispheres. Approximately 25 species have been recorded in Africa, though this number may be reduced with further taxonomic work.

Plants small to medium sized, occasionally robust, forming rather dense tufts, green to reddish- or golden-brown. Stems mostly erect, occasionally subascending, simple or with few branches; often tomentose below. Leaves erect to suberect, twisted or crispate when dry, spreading to squarrose-recurved when wet, oblong, elliptical to oblong-lanceolate or linear, ca 1.0–3.5 mm long, apex acute to acuminate, margins plane or recurved below, entire to distally toothed above; costa single, strong, subpercurrent to short excurrent; upper laminal cells hexagonal-rounded, pluripapillose, papillae small, conical; basal laminal cells larger, mostly rectangular, smooth or weakly papillose, firm-walled or lax and mostly hyaline. Gemmae frequently produced on rhizoids or in leaf axils, clavate or ellipsoid. Autoicous or dioicous. Perichaetia terminal, leaves little differentiated. Seta elongate, twisted anticlockwise viewed from above, 2–13 mm long, erect, smooth. Capsule erect, symmetrical, urn subcylindrical to narrowly pyriform, 8-ribbed, neck short tapered; stomata superficial at base. Operculum conic-rostrate. Peristome double or single, rudimentary or absent, exostome teeth 16, joined in 8 pairs, papillose to papillose-striate; endostome segments 8 or 16, narrow, lightly papillose, striate or smooth. Calyptra cucullate, naked or sparsely hairy. Spores papillose.


Zygodon intermedius
Bruch & Schimp. A: Habit (dry). B: Capsules. C: Calyptra. D: Branch leaves.
E: Upper laminal cells. F: Basal laminal cells. G: Gemmae. All drawn from Magombo M4391a, Malawi (BM).

Habitat. Epiphytic, on branches and trunks of shrubs and trees, occasionally on rocks and in rock crevices, shaded to exposed sites, 1000–4800 m.

Discussion. The genus is characterized by the twisted to secund, or erect to appressed leaves when dry, finely pluripapillose laminal cells with papillae often minute and centric over the lumen and the smooth, usually naked, cucullate calyptra. Gemmae are often present and provide useful aides to identification. The genus Leptodontiopsis has recently been placed into Zygodon by Goffinet et al. (2004).

Literature. Goffinet, B., Shaw, A. J., Cox, C.J., Wickett, N.J., Boles, S.B. 2004. Phylogenetic inferences in the Orthotrichioideae (Orthotrichaceae, Bryophyta) based on variation in four loci from all genomes. pp. 270–289 in Goffinet, B., Hollowell, V., Magill, R. 2004. Magill, R.E., Van Rooy, J. 1998. Flora of Southern Africa. Bryophyta. Part 1. Mosses. Fasc. III. Erpodiaceae – Hookeriaceae. In: Leistner, O.A., Flora of Southern Africa. Republic of South Africa: Botanical Research Institute, Department of Agriculture and Fisheries. Malta, N. 1926. The genus Zygodon Hook. et Tayl. Latvijas Universitates Botaniská Dárza Darbi 1: 1-185 [dated, some keys and illustrations].


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submitted 28.01.2007
uploaded 01.02.2007
amended 10.09.2008, 25.10.2008