A taxonomic revision of Aneuraceae (Marchantiophyta) from eastern Africa with an interactive identification key Author Reeb, Catherine Author Gradstein, Robbert Institut de Systématique Évolution Biodiversité, Sorbonne Université, MNHN, CNRS, EPHE, UMR 7205 Museum national d’Histoire naturelle, 57 rue Cuvier 75231 Paris cedex 05 (France) text Cryptogamie, Bryologie 2020 2020-01-29 20 2 11 34 http://dx.doi.org/10.5252/cryptogamie-bryologie2020v41a2 journal article 10.5252/cryptogamie-bryologie2020v41a2 1776-0992 12215441 Riccardia vohimanensis Reeb & Gradst. sp. nov. ( Fig. 4 U-X) DIAGNOSIS . — Monoicous. Thallus rigid, unwinged, with short branches. Axis plano-convex to biconvex, 8-12 cells thick, ventral side with mycorrhiza-like fungi. Immature calyptra strawberry-like. TYPE . — Madagascar . Vohimana Reserve, 18°55’43.6S 48°29’53.6”E 849 m , 15.IV.2010 , Reeb, Andriamantena & Bidault CRAE 96 * ( holo- , PC [ PC 0771053]). FURTHER SPECIMENS EXAMINED . — Madagascar . Alaotra-Mangoro, Zahamena Reserve, 17°38’22”S , 48°38’47”E , 1247 m , 27.XII.2013 , Reeb CR 13 Z 23* ( PC 0763868); Maromizaha Reserve, 18°58’33.9”S 48°27’54.3”E , 1021 m , 05.VII.2012 , Reeb MTM1278* ( PC 0763879), 18°58’45”S , 48°27’51.8”E , 1011 m , 06.VII.2012 , Reeb MTM1290* ( PC 0763878); Haute Matsiatra, Andringitra Nat. Park, 22°08’4061” S , 46°53’47.4”E , 1590 m , 21. V .2016 , Reeb CR 16 M 52 ( PC ). Malawi . Mulanje Mt., 15°53’32.1”S , 35°29’24”E , 2180 m , 22. VI .1991 , O’Shea M 7327A-2* ( E 00430480). Mauritius . Macabé, 550 m , 03.X.1962 , Een M 028* (S-B7097). DISTRIBUTION . — Malawi , Madagascar , Mauritius . HABITAT . — On dead logs (bare, smooth and very hard wood) and buttresses, rarely on humid rock, from 550 m to 2200 m . DESCRIPTION Monoicous (autoicous or paroicous). Thallus Leathery and rigid, green to blackish green when fresh and forming rosettes on bare substrates, dull brown to black in herbarium, closely attached to the substrate, to 22 mm long, 1-2-pinnate, not palmate, branches alternate, not flagelliform, stolons lacking. Main axis Well-defined, 700-1000(-1200) µm wide, in cross section plano-convex to concave-convex, with mycorrhizal fungi in the ventral part, 8-12 cells thick, margins obtuse, not winged, epidermis cells 2-4× smaller than inner cells. Ultimate branches Oblong and stocky, to 2 mm long and 1 mm wide, in cross section biconvex to plano-convex, 7-9 cells thick, margins acute, not winged, branch apex rounded and often widened, emarginate to weakly dissected, without overlapping edges. Mucilage papillae Apical and lateral. Oil bodies Not seen. Sexual branches Numerous all along axis, often close to each other. Male branches Mainly grouped, sessile, 300-400 µm long, not winged, with 4-8 antheridial pairs. Female branches Grouped, laterally inserted, 300-500 µm long, base often elongate, female branch bordered by scales or long hair-like, straight cilia, the cilia longer than the width of the axis, archegonia in 4-6 pairs. Calyptra Less than 1 mm long, strawberry-like when immature, densely covered by rounded, thick-walled cells. Gemmae Sometimes present.