Benthamia herminioides subsp. arcuata H.Perrier Perrier 1934: 36 Revision of the genus Benthamia A. Rich. (Orchidaceae, Orchidioideae, Habenariinae) Hervouet, Jean-Michel Descourvières, Pascal Hermans, Johan Longou, Ludivine Adansonia 2025 3 2025-07-21 47 11 171 249 (H. Perrier) Descourv. & Hervouet Descourv. & Hervouet 2025 Hervouet & Descourvières & Hermans & Longou 2025 [836,1428,1140,1168] Liliopsida Orchidaceae Benthamia Plantae Asparagales 13 182 Tracheophyta species arcuata comb. nov., stat. nov.  ( Figs 8; 9)     Benthamia herminioidessubsp. arcuataH.Perrier, Bulletin de la Société botanique de France81 (  Perrier 1934: 36).    TYPE  MATERIAL. —   Madagascar• Diana, Mt.Tsaratanana; 14°01’17”S, 48°57’60”E; alt.  2600-2880 m;  IV.1924;  H. Perrier16477; holotype: P[ P00094514]!.   ETYMOLOGY. — From Latin “ arcuatus”, curved like a bow, in reference to the shape of the ovary.   PHENOLOGY. — April and October-November.   DISTRIBUTION AND ECOLOGY. — Madagascar. In montane ericoid thicket, in the north between 1850 and 2150 m( Fig. 10).  Benthamia herminioidessubsp. arcuatais listed by Szelengowicz & Tamon (2013: 245)for La Réunion. The text refers to the Madagascan species but the two photographs show  Benthamia perfecundaon the left and  Benthamia mascula sp. nov.on the right.   CONSERVATION. — Sofar known only from Mt. Marojejy in Savaregion and Mt. Tsaratanana in Dianaregion, the two northernmost regions in Madagascar. On Marojejyit grows in a very confined area but within a National Park. Inview of our observations in Mt. Marojejy, it is considered Vulnerable( VU) according to criterion D1, number of mature individuals fewer than 1000. The population of Mt.Tsaratananahas not been documented since its discovery in 1924.   ADDITIONAL SPECIMENS EXAMINED. —   Madagascar• Sava, sommet oriental du massif de Marojejy; 14°26’48”S, 49°44’06”E; alt.  1850-2137 m;  26.III-2.IV.1949;  H. Humbertet al. 23755; P[ P00692986, P00692987]!, G•  Sava, district d’Andapa, Massif du Marojejy; 14°26’48”S, 49°44’06”E; alt.  2000-2137 m;  XI.1972;  P. Morat4025; P[ P00692452]! •  Sava, district d’Andapa, Massif du Marojejy; 14°26’48”S, 49°44’06”E; alt.  2000-2137 m;  XI.1972;  P. Morat4039; P[ P00692453]! •  Sava, district d’Andapa, camp n°5, on the summit of Marojejy; 14°26’48”S, 49°44’06”E; alt.  2100 m;  XI.1996;  N. Messmeret al. 372; P[ P02103086]!, K[ G00163180]!, MO, S•  Sava, district d’Andapa, RNI de Marojejy; 14°26’48”S, 49°44’06”E; alt.  2000-2137 m;  16.XI.1996;  M. Rakotondrainibe3694; P[ P01778632]! •  Sava, district d’Andapa, RNI de Marojejy; 14°26’48”S, 49°44’06”E; alt.  2050 m;  22.XI.2003;  H.H. Schmidtet al. 4263; MO[ MO3022641]!.   NOTES Perrier noted that the lateral lobes of lip are narrow and acute, which could not be verified on the type. The species was first described as a sub-species of  Benthamia herminioidesSchltr.but is readily distinguished by the larger flowers, the fleshy and thick floral parts and the very prominent callus on the lip. Specimens from Mt. Marojejy and Mt. Tsaratanana should be compared when fresh material becomes available from the latter locality. There is no obvious difference in dry material but the flowering seasons are different. See also: Perrier (1939: 37), Cribb & Hermans (2009: 48).   DESCRIPTION Erect terrestrial herb, 19-35 cmtall. Tubers 15-20 × 5 mm, 4- 7 roots up to 7 cmlong, 3 mmin diameter. Stem erect, 1-2.5 mmin diameter, green, with 2-5 sheaths regularly spaced. Leaves 1-2, basal, 30-50 mm× 10-20 mm, narrowly ovate to ovate, acute, coriaceous, glossy. Rachis 4-12 cm, mostly secund, shorter than half of the inflorescence, bearing 10-30 flowers 2-5 mmapart. Floral bracts lanceolate, acuminate, 5-6 mmlong, smaller or only slightly longer than the ovary. Ovary fusiform, curved at apex, 4-6 mmlong. Flowers at right angle to ovary, hardly opened, campanulate, 2.5-4 mmlong, all floral parts fleshy and thick, yellowish green; dorsal sepal, slightly apiculate at apex, concave, oblong, 2-2.3 × 0.8-1.2 mm; lateral sepals spreading, oblong or slightly obovate, navicular, green, 2 × 0.8-1 mm; petals oblong, adnate to the dorsal sepal, 1.9-2 × 1-1.1 mm, apex sub-acute to obtuse, slightly asymmetric, forming a hood with the dorsal sepal; lip 2-3 × 1-1.8 mm, with a very prominent longitudinal callus, trilobed, lateral lobes 0.3- 1 × 0.5-0.7 mm, midlobe 0.5-1 mm× 0.5-0.7 mm; spur curved, adpressed to the ovary, 0.6-0.8 mmlong, slightly bilobed. Column subterete, 0.6-1 mmhigh, 0.5 mmin diameter, with a short apiculus at apex; rostellum trilobed, short, with midlobe rounded; auricles strap-shaped, half the column length. 5898708396 1924-04 P H. Perrier Madagascar 2740 -14.021389 Mt. Tsaratanana 21 48.966667 13 182 P00094514 1 Diana holotype 5898709001 1949-03-26 1949-04-02 1949-03-26 P, G H. Humbert Madagascar 1994 14 183 -14.446667 Madagascar 21 49.735 13 182 P00692986, P00692987 1 5898708621 1972-11 P P. Morat Madagascar district d'Andapa 2069 -14.446667 Massif du Marojejy 21 49.735 Sava 14 183 P00692452 1 5898708884 1972-11 P P. Morat Madagascar district d'Andapa 2069 -14.446667 Massif du Marojejy 21 49.735 Sava 14 183 P00692453 1 5898708466 1996-11 P, K, MO, S N. Messmer Madagascar district d'Andapa 2100 -14.446667 camp n ° 5, on the summit of Marojejy 21 49.735 Sava 14 183 P02103086, G00163180 1 5898708638 1996-11-16 P M. Rakotondrainibe Madagascar district d'Andapa 2069 -14.446667 RNI de Marojejy 21 49.735 Sava 14 183 P01778632 1 5898708519 2003-11-22 MO H. H. Schmidt Madagascar district d'Andapa 2050 -14.446667 RNI de Marojejy 21 49.735 Sava 14 183 MO3022641 1