Nova Hedwigia 83 1—2 199—205 Stuttgart, August 2006 Orthotrichum galiciae (Orthotrichaceae, Bryopsida), a new species from Ethiopia by F. Lara1, R. Garilleti2 and V. Mazimpaka1 1 Departamento de Biología (Botánica). Facultad de Ciencias. Universidad Autónoma de Madrid. Campus de Cantoblanco, E-28049 Madrid. Spain. 2 Departamento de Botánica. Facultad de Farmacia. Universidad de Valencia. Avda. Vicente Andrés Estellés s/n. E-46100 Burjasot, Valencia. Spain. With 11 figures Lara, F., R. Garilleti & V. Mazimpaka (2006): Orthotrichum galiciae (Orthotrichaceae, Bryopsida), a new species from Ethiopia - Nova Hedwigia 83: 199-205. Abstract: A new epiphytic Orthotrichum species (O. galiciae F.Lara, Garilleti & Mazimpaka) is described from highlands of Simien Mountains, Northern Ethiopia. The new species is placed in the subgenus Gymnoporus (Braithw.) Limpr., section Leiocarpa Mol., and is proposed on the basis of the following character combination: leaves ovate-lanceolate with widely revolute margins, capsules emergent and slightly furrowed, exostome with 8 pairs of roughly papillose teeth, endostome formed by 8 tall, triangular-subulate, roughly papillose segments, and spores 14-19 µm in diameter. Key words: Mosses; Orthotrichum affine; Lobelia rhynchopetala; Simien mountains; Eastern Africa. Introduction In Africa, the genus Orthotrichum is only represented in four areas: 1) the Canary Islands and Madeira, 2) the Maghrib (from Morocco to Tunisia), 3) the mountains and high plateaux of Eastern Africa, in the surroundings of the Rift valley (from Ethiopia to Rwanda and Tanzania) and 4) the extreme south and south-east of Africa (South Africa and Lesotho). North of the Sahara desert, the genus is represented by 25 species (Ros et al. 1999, Draper et al. 2005), most of which are holarctic taxa distributed in Europe, and/or the Mediterranean basin. For tropical Africa, the genus has been revised by Lewinsky (1978) and, later, by Magill & van Rooy (1998) for Corresponding author: vicente.mazimpaka@uam.es DOI: 10.1127/0029-5035/2006/0083-0199 0029-5035/06/0083-0199 $ 1.75 © 2006 J. Cramer in der Gebrüder Borntraeger Verlagsbuchhandlung, D-14129 Berlin · D-70176 Stuttgart 199 the extreme south of the continent; nowadays 13 species are recognised in Africa south of the Tropic of Cancer, most of which are continental endemics (Lewinsky 1993). In eastern Africa, only 8 species have been recorded: Orthotrichum arborescens Thér. & Nav. and O. denticulatum Lewinsky (endemics of central East Africa), O. subexertum Müll.Hal. (continental endemic), O. firmum Venturi (distributed in Africa and India), O. aequatoreum Mitt. (pantropical), O. affine Brid. (mainly holarctic), as well as O. rupestre Schwägr. and O. diaphanum Brid. (subcosmopolitan). These species preferably grow as epiphyte in forests and scrubs at altitudes from 1500 to 5000 m a.s.l. (Lewinsky 1978). We recently got the opportunity to study material of the genus Orthotrichum collected by Dr. David Galicia in Simien mountains, Ethiopia. Among them was found a cushion of a moss that has superficial similarities with O. affine, from which it clearly differs in leaf shape and endostome structure. These and other characters constituted a unique character combination that allowed to describe it as a new species, which is dedicated to its collector, our ancient and appreciated workmate at the Universidad Autónoma de Madrid. Description Orthotrichum galiciae F.Lara, Garilleti & Mazimpaka, sp. nov. Figs. 1-11 Plantae usque ad 2 cm altae, folia ovata-lanceolata revolutis marginibus, capsulae emergentes, leviter sulcatae, exostoma 8 paribus valde papillosorum dentium, endostoma 8 segmentis altis, triangularsubulatis valde papillosisque. Operculum longe rostratum, basi cum rubere annulo; calyptra multiseriatis pilis munita; sporae 14-19 µm. TYPE: Ethiopia: Bwahit, Simien Mountains, 4300 m a.s.l., epiphyte on Lobelia rhynchopetala, D. Galicia, 8 October 2005. HOLOTYPE: BM. ISOTYPES: VAL-Briof and author’s herbarium at Universidad Autónoma de Madrid. Plants up to 2 cm tall, in dense tufts, olive-green to brownish-green above, brown below. Rhizoids reddish-brown, smooth, well developed at stem bases. Stems usually well branched, reddish, rounded in section, scleroderm 2-3 layered. Leaves erect appressed, concave and slightly carinate, somewhat flexuose at the apex when dry, patent to spreading, flexuose when moist; ovate-lanceolate, frequently broadly so; sometimes undulate at margins; (2.50-)3.00-3.75(-4.35) × (0.95-)1.10-1.50(-1.95) mm. Costa thin, 40-50 µm wide in middle and basal part of leaves, ending shortly below apex, more rarely percurrent. Margins broadly revolute from base to near apex. Apices acute to acuminate, sometimes apiculate or asymmetric. Basal leaf cells rectangular to trapezoid, with thin or thick, smooth or nodose walls, (40-)50-90(-100) × 9-14 µm; wider, short rectangular to quadrate at margin, (11-)20-45(-50) × (10-)13-21(-24) µm; somewhat differentiated at corners. Upper leaf cells irregularly rounded to ellipsoid, walls thin to moderately thickened, slightly bulging, 10-23 × 8-14(-17) µm; with 1-2(-3) simple, low papillae on both sides of the leaf lamina. Brood bodies not seen. Goniautoicous. Perigonia numerous, regularly distributed on stem and main branches, gemmiform, reddish; perigonial leaves ovate, brown. Perichaetia terminal, perichaetial 200 Figs. 1-6. Orthotrichum galiciae F.Lara, Garilleti & Mazimpaka, sp. nov. Fig. 1. Dry cushion. Fig. 2. Plant when moist. Figs. 3-4. Leaves. Figs. 5-6. Leaf apices. All from holotype. 201 202 leaves not differentiated; usually with 2-3 capsules per perichaetium, rarely only a single capsule. Capsules immersed to emergent, ellipsoid-cylindrical, slightly 8-ribbed in upper half when dry and full of spores, 1.90-2.40 × 0.67-1.00 mm; ellipsoid when wet and full of spores, gradually narrowed to a 0.6-0.9 mm long seta; mature capsules green-yellowish, turning brown when old. Exothecial cells rectangular, slightly differentiated in the upper part of capsule into 8 bands formed by 7-8 somewhat wider and coloured cells; below the mouth with 3-4 rows of smaller, coloured rounded-quadrate or oblate cells. Stomata phaneroporous, in middle and lower part of capsule, with surrounding cells well differentiated. Peristome double, pale yellow, sometimes with remains of a low papillose prostome. Exostome formed by 8 pairs of roughly and evenly papillose teeth, in old capsules some teeth splitting into two; teeth reflexed to revolute when dry; OPL (outer peristomial layer) ornamentation formed by rough, simple or divided papillae densely disposed, larger and more sparse in the upper tooth part, clavate in lateral view; ornamentation of the exostomial PPL (principal peristomial layer) formed in the lower 3-5 cells with small papillae disposed on longitudinal, low stripes; in the upper part with rough, irregular, not very densely disposed papillae. Endostome of 8 functional triangularsubulate segments, as long as or somewhat longer than exostomial teeth, with irregular margins, symmetrically biseriate; endostomial PPL ornamented with minute and sparse papillae; IPL (inner peristomial layer) with rough, rounded and pedicellate papillae more or less openly disposed, low, small and densely disposed in the subula; connecting membrane absent. Operculum conical, longly rostrate, yellowish with a basal reddish rim. Spores globose, brown or greenish, slightly papillose or smooth, 14-19 µm in diameter. Vaginula naked. Calyptra conic-oblong, plicate, 2.6-2.7 mm long, with stout, long, multiseriate, crenulate to dentate, smooth to papillose hairs, more abundant in the upper part of calyptra. Discussion Orthotrichum affine is the only species from eastern Africa that has immersed or emergent capsules and phaneroporous stomata. Its sporophytes are similar to those of O. galiciae in the operculum longly rostrate with a basal reddish rim, and in the hairy calyptra. However, both species are easily distinguished by their distinct leaf morphology, and, especially, by their different peristomial constitution. In Orthotrichum galiciae, the leaves are broadly wide, concave, and hardly keeled. Their costa is very slender and little prominent, and their margins are broadly revolute (Figs. 3, 4). Conversely, Orthotrichum affine has narrower leaves that are clearly keeled, and exhibit a strong and dorsally prominent costa, as well as recurvate and narrower margins. Figs. 7-11 Orthotrichum galiciae F.Lara, Garilleti & Mazimpaka, sp. nov. Fig. 7. Dry capsule with operculum. Fig. 8. Dry capsule mouth. Fig. 9. Calyptra apex. Fig. 10. Stoma. Fig. 11. Peristome, with the endostome on the foreground. All from holotype. 203 As for the peristome, both species present 8 pairs of exostome teeth and 8 endostome segments. However, they clearly differ in segment structure and ornamentation. In Orthotrichum galiciae endostomial segments are functional, wide, triangular with a subulate apex (Figs. 8, 11). They are as long as or somewhat longer than the exostome teeth, and are ornamented by papillae on both faces: small and fine papillae dispersed on the external face (PPL), and large and prominent rounded papillae on the internal one (IPL). In O. affine segments are not functional. They are thinner, linear-lanceolate, shorter than the exostome teeth, smooth on the PPL and with low papillae and papillose lines on the IPL. The structure, form and ornamentation of the endostome segments are characters of great importance in the taxonomy and systematics of the genus Orthotrichum (Lewinsky 1993; Lewinsky-Haapasaari & Hedenäs 1998). Within the subgenus Gymnoporus (Braithw.) Limpr. to which these 2 taxa belong, the typical endostome of O. affine is characteristic of section Affinia Schimp., whereas that of O. galiciae is typical of section Leiocarpa Mol., according to Lewinsky’s criterion (1993). There are other differences taxonomically less relevant, but valuable for the differentiation of these two taxa: 1) dry capsules in Orthotrichum affine are strongly furrowed, and have exothecial bands that are formed by clearly thick-walled cells, whereas O. galiciae has weakly furrowed capsules, whose exothecial bands cells are hardly thick-walled (Fig. 7); 2) in O. affine the exostome ornamentation is variable, although generally consisting of fine and densely disposed papillae, or papillose lines differently oriented and always little prominent, while in O. galiciae the ornamentation basically consists of thick prominent papillae, irregularly shaped and not densely disposed (Fig. 11); 3) O. affine calyptras are little or not hairy, with slender and short hairs, whereas calyptras in O. galiciae are more hairy (Fig. 9) and have thicker and longer hairs. Two species from the Cape region (Lewinsky & van Rooy 1990) are similar to Orthotrichum galiciae: O. incurvomarginatum Lewinsky & van Rooy and O. armatum Lewinsky & van Rooy. The former one is easily discriminated from O. galiciae by: leaves with incurvate margins, differentiated perichaetial leaves, endostome segments somewhat narrower, shorter and with less irregular margins, operculum shortly rostrate, and spores papillose, 16-25 µm in diameter. Orthotrichum armatum differs in its narrow and keeled leaves that have a characteristic pointed apex, and plane margins in the upper leaf third, in the endostome segments blunt and not subulate, and, finally, in the spores papillose, 25-34(-53) µm in diameter. Outside the African continent, the closest species to Orthotrichum galiciae is the South American O. araucarieti Müll. Hal. ex Broth., which has narrower leaves with finely revolute margins, stomata surrounded by radiating cells, exostome teeth reddish and finely papillose, and spores clearly larger, 26-29 µm in diameter. Acknowledgements This work was funded by the Spanish Ministry of Education and Science, grant n° CGL200403513. 204 References DRAPER, I., V. MAZIMPAKA, B. ALBERTOS, R. GARILLETI & F. LARA (2005): A survey of the epiphytic bryophyte flora of the Rif and Tazzeka Mountains (northern Morocco). - J. Bryol. 27: 23-34. LEWINSKY, J. (1978): The genus Orthotrichum Hedw. (Musci) in Africa south of the Tropic of Cancer. - Bot. Tidsskr. 72: 61-85. LEWINSKY, J. (1993): A synopsis of the genus Orthotrichum Hedw. (Musci, Orthotrichaceae). Bryobrothera 2: 1-59. LEWINSKY, J. & J. VAN ROOY (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. - J. 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