Taxonomic study of the fern genera Abrodictyum C. Presl and Trichomanes L. (Hymenophyllaceae, Polypodiidae) in the western Indian Ocean, and description of a new Abrodictyum species for Madagascar Author Dubuisson, Jean-Yves Author Bauret, Lucie Institut Systématique Evolution Biodiversité (ISYEB), Sorbonne Universités, MNHN, CNRS, UPMC, EPHE, Herbier National, 57 rue Cuvier, CP 39, 75005 Paris, France. Author Grall, Aurelie Royal Botanic Gardens, Kew, Richmond, Surrey, TW 9 3 AE, United Kingdom. Author Senterre, Bruno Island Biodiversity & Conservation Centre, associated with the University of Seychelles, Anse Royale, Mahé, P. O. Box 1348, Seychelles. & Evolutionary Biology & Ecology - CP 160 / 12, Université Libre de Bruxelles, 50 Av. F. Roosevelt, 1050 Bruxelles, Belgium. Author Said, Ahamada H. Institut Systématique Evolution Biodiversité (ISYEB), Sorbonne Universités, MNHN, CNRS, UPMC, EPHE, Herbier National, 57 rue Cuvier, CP 39, 75005 Paris, France. Author Pynee, Kersley The Mauritius Herbarium, Agricultural Services, Agronomy Division, Ministry of Agro-Industry and Food Security, Réduit, Mauritius. Author Ebihara, Atsushi Department of Botany, National Museum of Nature and Science, 4 - 1 - 1 Amakubo, Tsukuba, 305 - 0005, Japan Author Hennequin, Sabine text Phytotaxa 2017 2017-11-10 327 3 201 222 http://dx.doi.org/10.11646/phytotaxa.327.3.1 journal article 10.11646/phytotaxa.327.3.1 1179-3163 13723223 Abrodictyum pseudorigidum Bauret & Dubuisson (2016: 161) . TYPE:— MADAGASCAR . Fianarantsoa : Ambatomboay, RNI d’Andringitra versant E, 40 km au Sud d’Ambalavao, sur les berges d’un affluent de la rivière Sahavatoy, 24 May 1995 , F. Rakotondrainibe 2708 ( holotype P, P00059914!). = Trichomanes rigidum Sw. var. lugubre H. Christ (1901: 849) . Type:— DEMOCRATIC REPUBLIC OF CONGO . Kisantu, without date, J.B. Gillet s.n . ( holotype BR, BR 0000013468675!). = Trichomanes rigidum Sw. var. annobonense Brause (1915: 378) . Type:— EQUATORIAL GUINEA . Annobon Island: Summit of Santa Mina, 650 m , October 1911 , G. W. J. Mildbraed 6700 ( holotype B, BW 20 0093175!). Terrestrial ferns. Rhizomes short, erect, 0.5–2.0 cm in diameter, bearing long tufted erect red-brown trichomes, especially densely covering apex, and numerous robust roots. Fronds clustered, erect; stipes (2–)11–16(–26) cm long, cylindrical to mostly canaliculate, wingless or thinly winged on their upper part only, bearing numerous scattered trichomes identical to those present on rhizomes; rachis and main pinna axes with trichomes similar to those on the stipes and rhizomes. Laminae (8.0–)10.0–26.0(–31.0) × (3.0–)7.5–16.0(–19.0) cm, mostly triangular, less often sublanceolate to narrowly ovate, with more or less lanceolate to attenuated apex, tri-pinnate-pinnatifid, coriaceous and more or less opaque; pinnae (2.0–)3.5–7.0(–9.0) × 0.5–2.0(–3.5) cm, horizontal to oblique, basally sub-opposite, then alternate, lanceolate, or triangular to linear, and pinnate; pinnules pinnatifid to bipinnatifid (up to tripinnatifid for the largest specimens), lanceolate to linear; ultimate segments 0.2–0.4 mm wide, linear and single-veined with acute to rounded ends, the veins not reaching the margin; venation pinnate and anadromous. Sori paratactic, located mostly on acroscopic basal-most segments of proximal pinnules, 1.0–2.0 × 0.6–0.9 mm , 1–3(–6) per pinnule, up to 20 (sometimes more than 30) per pinna, free with a thin wing mostly at the base, cylindrical, truncated to slightly bilabiate with a slightly dilated mouth; receptacle short to long-exerted. Distribution and habitat: —Sub-Saharan wet tropical Africa to western Indian Ocean (but absent from Mascarenes and Seychelles ), terrestrial in the understory of rainforests from low to high elevations ( 200–2,500 m ) ( Table 1 ). Specimens examined: — COMOROS . Anjouan : 1875, M. Lavanchie s.n. (P00139638) ; May 1850 , L.H. Boivin s.n. (P00139623); 1875, J.M. Hildebrandt 1793 (P00139637); Mjimandra , April 2011 , E. Bidault 109 (P02439773) . Grande Comore : La Convalescence , versant ouest, November 2002 , F. Rakotondrainibe 6771 (P00312031) ; Versant ouest du volcan Karthala , bois proche de Convalescence , October 2008 , M. Pignal 3381 ( P02439785), M. Pignal 3391 ( P02439789) . Mohéli : Forêt de Saint Antoine , September 1995 , N. Moulaert F.099 (P01485567) ; Chalet St Antoine , November 2008 , M. Pignal 3473 (P00684891). Without locality: 1885, L. Humblot 1328 (P00139639, P01526320, P01526319, P00312496, P01430232, P01430231) ; without date, L.H. Boivin s.n. (P00301468). — MADAGASCAR . Antsiranana : Befingotra , RS d’Anjanaharibe-Sud , sur le versant Sud-Est , October 1994 , F. Rakotondrainibe 2097 (P0006321), 2097 bis (P0006322) ; November 1994 , 2533 (P00046997); RNI 12 du Marojejy , au bord d’un affluent de la rivière Manantenina , October 1996 , F. Rakotondrainibe 3374 (P00084841), 3390 (P00084866) ; Forêt de Betaolana , October 1999 , F. Rakotondrainibe 4851 (P00179413) ; Forêt d’Analabe (massif d’Anjanaharibe-Sud ), October 1999 , F. Rakotondrainibe 5052 (P00179699), 5092 (P00181052) ; PN de Marojejy, October 2001 , F. Rakotondrainibe 6241 (P00243886). Fianarantsoa : Ambatomboay , RNI d’Andringitra versant Est , May 1995 , F. Rakotondrainibe 2708 (P00059914) ; Réserve Spéciale d’Ivohibe , October 1997 , F. Rakotondrainibe 4164 (P00134183), 4172 (P00134193), 4271 bis (P00134306) ; Corridor reliant les réserves d’Andringitra et d’Ivohibe , October 1997 , F. Rakotondrainibe 4346 bis (P00134417) ; PN de Ranomafana , Forêt de Vatoharanana , October 2000 , F. Rakotondrainibe 5916 (P00212397) ; Forêt de Vinanitelo , October 2000 , F. Rakotondrainibe 6149 (P00212702) . Mahajanga : Daraina , Forêt de Binara , November 2001 , F. Rakotondrainibe 6508 (P00248610) . Toamasina : Ambanizana , Piste menant au sommet d’Ambohitsitondroinan’ Ambanizana , sur le versant ouest, December 1993 , F. Rakotondrainibe 1872 (P0006067) ; PN de Zahamena , Antanandava , January 2001 , A. Rasolohery 241 (P00246411) ; PN de Zahamena , a 2 km d’Ankosy , le long de la SGR, June 2001 , A. Rasolohery 502 (P00233447), 534 (P00233462) . Toliara : Eminiminy , Parcelle 1, R.N.I. n°11 d’Andohahela , October 1995 , F. Rakotondrainibe 2893 (P00066991) ; Forêt d’Andranomay , December 1996 , F. Rakotondrainibe 3791 (P00084658) ; Forêt d’Andrambovato , October 2000 , F. Rakotondrainibe 5996 (P00212501), 5998 (P00212503) .