Revision of the genus Benthamia A. Rich. (Orchidaceae, Orchidioideae, Habenariinae) Author Hervouet, Jean-Michel Fédération France Orchidées (FFO) and Muséum national d’Histoire naturelle, Direction générale déléguée aux collections, Herbier national, case postale 39, 57 rue Cuvier 75005 Paris (France) jmhervouet @ free. fr jmhervouet@free.fr Author Descourvières, Pascal France Orchidées (FFO), 27 rue Auguste Blanqui, 94400 Vitry-sur-Seine (France) descourvieres. pascal @ neuf. fr descourvieres.pascal@neuf.fr Author Hermans, Johan , Royal Botanic Gardens, Kew, Richmond, Surrey, TW 9 3 AE (United Kingdom) and Core Facility, Botanical Garden, University of Vienna, Rennweg 14, 1030, Vienna (Austria) j. hermans @ kew. org j.hermans@kew.org Author Longou, Ludivine Atelier d'iconographie scientifique, UAR 2047 DoHNÉE, MNHN / CNRS, Muséum national d’histoire naturelle, 57 rue Cuvier, 75005 Paris (France) ludivine. longou @ mnhn. fr ludivine.longou@mnhn.fr text Adansonia 2025 3 2025-07-21 47 11 171 249 https://sciencepress.mnhn.fr/sites/default/files/articles/pdf/adansonia2025v47a11.pdf journal article 313251 10.5252/adansonia2025v47a11 b8e5d9ec-7e27-4bbf-a8a8-6cee2bf7465f 1639-4798 16262489 Benthamia monophylla Schltr. ( Figs 76 ; 77 ) Repertorium Specierum Novarum Regni Vegetabilis 33: 30 ( Schlechter 1924 ) . TYPE MATERIAL . — Madagascar • Haute Matsiatra , massif d’Andringitra ; alt. 2200-2600 m ; III.1922 ; H. Perrier 14387 ; holotype : P [ P00094540 ]!; isotype : P [ P00094541 ] !. ETYMOLOGY . — “ Monophylla ”, in Greek with a single leaf. PHENOLOGY . — January to April. FIG . 76. — Benthamia monophylla Schltr. : Andringitra massif, Madagascar, 7 April 2018. Photograph by Jean-Michel Hervouet. DISTRIBUTION AND ECOLOGY . — Madagascar . A high elevation plant, from 1600 to 2600 m , found in the southern half of the country, mostly from Andringitra massif (Haute Matsiatra region) to Andohahela in the south (Anosy region), in humid mountain grasslands or small patches of vegetation on rocks ( Fig. 78 ). FIG . 77. — Benthamia monophylla Schltr., Andringitra massif, Madagascar, 7 April 2018. Photograph by Jean-Michel Hervouet. CONSERVATION . — This species has a large EOO and is locally abundant, but the AOO is probably less than 2000 km ². It was quoted NT by IUCN in 2016 (https://doi.org/10.2305/IUCN. UK .2018-1.RLTS.T44393380A69785668.en). ADDITIONAL SPECIMENS EXAMINED . — Madagascar • Analamanga , near Mandraka ; 18°55’30”S , 47°56’20”E ; XII.1905 ; C. d’Alleizette 7066b ; L [ L1487725 ] ! • Haute Matsiatra , pic Boby , Andringitra ; 22°11’S , 46°53’E ; 1946; A.M. Homolle 1192 ; P [ P02115319 , P02115320 ] ! • sine loc. ; 1946; A.M. Homolle 1263 ; P [ P00692277 ] ! • sine loc. ; 1946; A.M. Homolle 1277 ; P [ P00692278 ] !• Anosy , massif de l’Andohahela ; 24°36’S , 46°42’E ; alt. 1800-1975 m ; I.1934 ; H. Humbert 13608 ; P [ P0009454 , P00094543 , P00094544 ]!, G !, TAN ! • Haute Matsiatra , canton Sendrisoa , district Ambalavao ; 22°13’S , 46°55’E ; 17.I.1958 ; C. Rakotovao 9938RN ; P [ P00692318 , P00692461 ] ! • Haute Matsiatra , 30 km NW of Fianarantsoa ; VIII.1963 ; W.Rauh 10613 ; HEID [ HEID2500341 ] !• Haute Matsiatra , pente du Vohidray , Andringitra ; 13.I.1971 ; J.L. Guillaumet 3761 ; TAN ! • Anosy , massif de l’Andohahela , RN11; I.1974 ; P. Morat 4389 ; P [ P00692454 , P00692455 ] ! • Haute Matsiatra , Andringitra reserve ; 22˚10’S, 46˚56’E; alt. 1975 m ; 13.I.1987 ; M. Nicoll 262 ; K [ K000453691 , K000453692 ]!, MO [ MO3022623 ]!, TAN ! • Haute Matsiatra , Andringitra , near to Pic Boby ; II.2007 ; T. Ranarivelo et al. 484 ; K !, TAN ! • Haute Matsiatra , Andringitra ; D. Roberts DLR119 & DLR120 ; K ! • Haute Matsiatra , Andringitra ; D. Roberts DLR125 ; K [spirit 76706] !. NOTES Plants sometimes have two basal leaves (e.g. on Ambondrombe). The flowers have a lip that is very similar to the petals and are reminiscent of some Holothrix in South Africa . It can form huge colonies, e.g. on Andringitra. With its elongate spur, this species is not a typical Benthamia with a short spur like the type of the genus, Benthamia latisatis . Perhaps it belongs to a different genus. The specimen H. Perrier 14387 has two sheets in P, but Perrier’s handwriting on specimen P00094540 clearly shows that it is the sheet sent to Berlin for the description by Schlechter, it is therefore the holotype . See also: Schlechter (1930 : t.11 n°42), Perrier (1939: 24) , Perrier (1939: 30) , Cribb & Hermans (2009: 42) , Cribb & Hermans (2009: 46) , Hervouet (2018: 169) . FIG . 78. — Distribution map of Benthamia monophylla Schltr. DESCRIPTION Erect terrestrial herb, 15-50 cm tall. Tubers 2, oblong-fusiform. Stem 1-4 mm in diameter, with 2-3 sheaths at the base and one radical leaf. Leaf 1 (rarely 2), linear to oblong, 6-15 cm × 6-35 mm , a little narrowed towards the base, somewhat acute or shortly acuminate. Rachis 8-15 cm long, subdense, unilateral, bearing 35-60 flowers. Floral bracts lanceolate-acuminate, 1.5-7 × 0.8-2 mm , normally equalling the flower or sometimes a little longer. Ovary 4.5-6.8 × 0.9-1 mm . Flowers about 3 mm wide, yellow; sepals elliptic-oblong, obtuse, 1-veined, 1.5-3 × 0.8-1.3 mm , lateral sepals navicular, dorsal sepal concave; petals 1.3-3 × 0.9-1.5 mm , as long as the sepals but a little wider and fleshy, oblong, obtuse, 2-veined and a little thickened towards the apex; lip concave, oval-elliptic, 1.8-3.4 × 0.9-1.75 mm , obtuse, entire or obscurely trilobed, the base 3-veined, the anterior part thickened and fleshy; spur narrowly conical, gradually narrowing towards the apex, 1.4-3.5 × 0.4-0.8 mm , somewhat curved. Column 0.5-1.1 × 0.4-0.9 mm , anther subglobose, very obtuse; auricles oblong, subcrenulate, half the length of the anther.