Benthamia litoralis Hervouet & Descourv., 2025

Hervouet, Jean-Michel, Descourvières, Pascal, Hermans, Johan & Longou, Ludivine, 2025, Revision of the genus Benthamia A. Rich. (Orchidaceae, Orchidioideae, Habenariinae), Adansonia (3) 47 (11), pp. 171-249 : 214-215

Benthamia litoralis Hervouet & Descourv. , sp. nov.

( Figs 61 ; 62 ; 63)

DIAGNOSIS. — Similar to Benthamia africana but differing by the strap-like basal leaves and the much longer lateral lobes of the lip (triangular acute half as long as the midlobe, vs obtuse and much shorter than midlobe in Benthamia africana ). The flowers are very similar to those of Benthamia flavida but have a smaller lip (lip 2-3.2 mm in Benthamia litoralis sp. nov. vs lip 3.6-5.1 mm in Benthamia flavida ), the latter species having very different alternate and erect leaves (vs strap-like and basal in Benthamia litoralis sp. nov.). It is also similar to Benthamia elata , which is a much larger plant (20- 41 cm for Benthamia litoralis sp. nov. vs 25-100 cm for Benthamia elata ) with different leaves (linear strap-like for Benthamia litoralis sp. nov. vs ligulate-lanceolate for Benthamia elata ), larger flowers and longer rachis (4.5-17 cm for Benthamia litoralis sp. nov. vs 20- 40 cm for Benthamia elata ).

TYPE MATERIAL. — Madagascar • Sava, parc National de Masoala , 1 km au Nord de la rivière Fampotakely; 15°35’S, 50°25’E; 18.IX.1994; G. M. Rahajasoa 434; holotype: P [ P00692457 ] !.

ETYMOLOGY. — From Latin “ litoralis ”, referring to the sea-shore, due to the vicinity of its habitat to the coast.

PHENOLOGY. — September-October.

DISTRIBUTION AND ECOLOGY. — Madagascar. It is restricted to low altitude sandy areas of littoral forest of the east coast ( Fig. 62 ). CONSERVATION. — This species is known from eight locations near the east coast of Madagascar but is locally abundant. It is assessed as Near Threatened (NT) because all the coastal biotopes are under threat in the east coast of Madagascar.

ADDITIONAL SPECIMENS EXAMINED. — Madagascar • Atsinanana, environs de Tamatave; VII.1914; H. Perrier 1843; P [ P00094600 , P00094601 ] ! • Sava, canton Ampanavoana, district d’Antalaha. RN 2; 15°41’00”S, 50°21’30”E; 23.IX.1953; H. Tsilizy 5485; P [ P00692312 ] ! • Sava, Masoala Peninsula, crest of Ambato Mountain , north of village of Antanadavahely; 15°16’18”S, 50°20’32”E; alt. 390 m; IX.1993; K. Lance 04; K! spirit • Sava, Masoala Peninsula, Ambatoavy escarpment, E. of Andranobe; 15°40’15”S, 49°58’42”E; 11.VII.1994; K. Lance 139; K ! • Sava, Maroantsetra, commune d’Abinanitelo, fokontany Ambalamahogo, Maimboro summit; 15°18’39”S, 49°22’43”E; alt. 1100 m; 6.IX.2004; P. Antilahimena 2840; P [ P00755154 ] ! • Sava , Tampolo in Masoala Peninsula; alt. 1 m; 4.XI.2005; photographs by Jean-Michel Hervouet • Atsinanana, Pangalanes, Lake Ampitabe ; 18°36’18”S, 49°12’47”E; 4.X.2019, J. Hermans 8358; K ! • Analanjirofo , Manompana, Ambodiriana forest; alt. 50 m; VII. IX.2023; photographs by Véronique Lavergne .

NOTES

Herbarium specimens of Benthamia litoralis sp. nov. look similar to Benthamia africana and B. elata and have been confused. Table 1 below outlines the main differences.

See also: Cribb & Hermans (2009: 45 as Benthamia cinnabarina (Rolfe) H.Perrier ).

DESCRIPTION

Erect terrestrial herb 20-41 cm tall. Tubers 2, elongated, pyriform, 2 cm × 4-7 mm, with 4-5 filiform roots up to 3 cm long. Stem cylindrical, 1-2 mm in diameter. Leaves 2-4, basal, amplexicaul, with around 13 veins, linear strap-like, acute, 30-200 × 4-20 mm. Rachis terminal, sub-dense, 4.5-17 cm, mostly unilateral, shorter than half of the stem, bearing 7-44 flowers, 2-5 mm apart. Floral bracts lanceolate, apiculate, single-veined, 3-7 × 0.75-1.3 mm, sheathing the ovary, as long as the ovary. Ovary fusiform, 3-7 mm long, 1-2 mm in diameter. Flowers yellowish green, resupinate, opening fully, overall 4 mm deep, 3 mm wide, 2 mm high; sepals subsimilar, slightly concave, linear, obtuse, dorsal sepal 2.75-3 × 0.6-0.8 mm, lateral sepals spreading, 2-3 × 0.5-1 mm; petals triangular linear, 2-3 × 0.5-0.8 mm; lip trilobed, 2-3.2 × 0.8-1.75 mm, all lobes triangular and acute; lateral lobes at 45° from the longitudinal axis of the lip, 0.3-0.5 mm long, central lobe 1-1.1 mm long; spur scrotiform or globular, very small, curved, 0.5-1 × 0.6-1 mm long, slightly wider than long. Column subterete, 0.6-1.1 × 0.7-1 mm, with rounded apex; auricles linear, nearly as long as the column; rostellum trilobed, short, with lateral lobes acute and midlobe rounded.

Figures

FIG. 61. — Benthamia litoralis Hervouet & Descourv., sp. nov., Palmarium, Canal des Pangalanes, Madagascar, 31 October 2012. Photograph by Jean- Michel Hervouet.

FIG. 62. — Distribution map of Benthamia litoralis Hervouet & Descourv.,sp.nov.