Benthamia melanopoda Schltr.

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 : 223

Benthamia melanopoda Schltr.

( Fig. 74 )

Repertorium Specierum Novarum Regni Vegetabilis 33: 29 ( Schlechter 1924).

TYPE MATERIAL. — Madagascar • Vakinankaratra, flanc est du mont Tsiafajavona; 19°22’S, 47°19’E; alt. 2000 m; III.1921; H. Perrier 13543; lectotype: P [ P00094534 ]!, here designated; isolectotype: P [ P00094535 and flowers in spirit] !.

ETYMOLOGY. — From the Greek “melano”, black, and “poda”, foot, due to the black sheaths at the base of the plant.

PHENOLOGY. — March to April.

DISTRIBUTION AND ECOLOGY. — Madagascar. From Analamanga south to Anosy region. Found in montane grassland, but also in marshes at Ambohitantely in Analamanga region, from 1500 m to 2000 m ( Fig. 75 ).

CONSERVATION. — This species is currently known from fewer than five locations, with an AOO less than 500 km ² and a habitat threatened by bushfires, it is therefore considered as Endangered (EN) according to criterion B2.

ADDITIONAL SPECIMENS EXAMINED. — Madagascar • Haute Matsiatra, au pied de l’Ambondrombe; 21°52’30”S, 47°15’37”E; alt. 1200 m; 10.IV.1941; P. Boiteau 4559; P [ P00692298 ] ! • Anosy, sommet de la Menakompy à l’est d’Ampandrandava; 24°07’S, 45°48’E; alt. 1100 m; IV.1943; A. Seyrig 658; P [ P00094533 ]!; det. Benthamia macra by Perrier ) • Vakinankaratra, Manjakatompo; 1. V.1951; R. Benoist 909; P [ P00692220 ] ! • Haute Matsiatra, Andringitra, versant du Vohidray; alt. 1500 m; 13. I.1971; J. L. Guillaumet 3760; TAN !.

NOTES The only Benthamia with basal lobes of the lip that can be longer than the midlobe. The very prominent callus at the apex of the lip is also very distinctive. The species was recorded from La Réunion by Szelengowicz & Tamon (2013: 247). The text refers to the Madagascan species but the photograph probably shows a withered Benthamia perfecunda .

See also: Schlechter (1930: t.11 n°41), Perrier (1939: 38), Cribb & Hermans (2009: 47), Hervouet (2018: 168).

DESCRIPTION

Erect slender terrestrial herb, 60-78 cm tall. Tubers 2, fusiform, elongated, ending in a root, roots 7-8, 1-2 mm in diameter. Stem 3-6 mm in diameter, with the base enveloped by 2-3 black sheaths, in the middle with leaves, higher up with several sheaths with their blade decreasing in size with height. Leaves 3-4, 10-12 × 0.8-1 cm, grass-like, clasping the stem. Rachis cylindrical, dense, bearing 36-90 flowers, 10-15 × 1.5 cm. Floral bracts narrowly lanceolate-acuminate, 7-18 × 1-2 mm, the lower ones up to three times longer than the flower. Ovary fusiform-cylindrical, twisted, 3.5-7 × 2-4 mm. Flowers butter yellow, 2-3 × 2.5- 3 mm without the ovary; sepals oblong, obtuse, slightly mucronate, 3-veined, dorsal sepal 2-2.6 × 1-1.4 mm, lateral sepals 2-2.6 × 1-1.4 mm, slightly asymmetrical; petals oval, obtuse, with one main vein and two smaller, 2-2.5 × 1.2-1.5 mm, almost as long as the sepals, but a little wider; lip broadly oval, 2-3 × 2-2.5 mm, concave, trilobed in the upper third; lobes oval-triangular obtuse, almost equal, the lateral lobes a little thickened and narrowed towards the tip, 0.3-0.7 mm long, sometimes larger than the midlobe, the midlobe very fleshy, with a very prominent central callus at the tip; spur very short, 0.8-1 × 0.5-0.7 mm, oblongly saccate, obtuse, thickened at the base. Column subterete, short, 0.6-0.7 × 0.5-0.8 mm, anther not apiculate, obtuse to hardly apiculate; auricles rounded, crenulate, almost half the length of the anther or smaller; rostellum trilobed, lateral lobes short, horizontal, midlobe toothed, erect, 0.1- 0.2 mm long. Capsules 6 × 3 mm, developing before the apical flowers have opened.

Figures

FIG. 74. — Benthamia melanopoda Schltr.: Ambohitantely, Madagascar, 10 March 2015. Photograph by Jean-Michel Hervouet.

FIG. 75. — Distribution map of Benthamia melanopoda Schltr.