Disperis humblotii Rchb.

Croix, Isobyl la, Bosser, Jean & Cribb, Phillip J., 2002, The genus Disperis (Orchidaceae) in Madagascar, the Comores, the Mascarenes and the Seychelles, Adansonia (3) 24 (1), pp. 55-87 : 75-76

15. Disperis humblotii Rchb. f.

Flora 68: 377 (1885); Schlechter, Bull. Herb. Boiss.

6: 954 (1898), in syn; H. Perrier in Humbert H. (ed.),

Fl. Madag., 49 e fam., Orchidées 1: 191 (1939); Du

Puy et al., Orch. Madag.: 135 (1999). — Type:

Humblot s.n., Comores (holo-, W!).

Disperis comorensis Schltr. in Engler, Bot. Jahrb. Syst. 24: 429 (1897); Bull. Herb. Boiss. 6: 946 (1898); Feddes Repert. Spec. Nov. Regni Veg. Beih. 33: 107 (1925); H. Perrier, Not. Syst. (Paris) 5: 227 (1936); in Humbert H. (ed.), Fl. Madag., 49 e fam., Orchidées 1: 192 (1939); Du Puy et al., Orch. Madag.: 134 (1999). — Type: Bang s.n., Comores, in Herb. Schlechter (holo-, B delet.); syn. nov.

A slender glabrous, terrestrial herb, 10-22 cm tall. Leaves 2-3, alternate, set around the middle of the stem, lamina narrowly ovate to ovate, acute at the apex, cordate at the base, 2-4 × 1- 2 cm, the lower one long petiolate, petiole 4- 7 mm long, the upper leaf sessile. Inflorescence 2-10-flowered; bracts lanceolate or ovate, acute, generally shorter than the ovary, 5-8 mm long. Flower rose-coloured or white. Dorsal sepal narrow, one-nerved, forming an oblong hood with the petals, 6-7 × 2.5-3 mm. Lateral sepals narrowly ovate, 9-10 × 2.5-3 mm, slightly falcate, obtuse at the apex, adnate in the basal quarter to half their length, 3-4-nerved, bearing an obtuse conical spur, 0.6-0.7 mm long, in the basal third. Petals linear-ligulate, 6-7 mm long. Lip 2 mm long, basal part linear, united to the column; terminal part 3-lobed; the two lateral lobes slightly divergent, oblong, 1.2- 1.5 mm long, rounded at the tips, concave on the inner face, outer face papillose-pubescent; mid-lobe stalked, fleshy, saddle-shaped, 1.5- 2.8 mm long, obtuse at the tip, rounded and gibbous at the base, upper surface shortly papillose-pubescent, but the gibbous base is quite glabrous; stipe linear, glabrous, flat, 2 mm long, attached to the basal third to the terminal appendage Rostellar arms short, 0.8 mm long, spathulate at tips. stigma transverse, subreniform. — Fig. 6G.

DISTRIBUTION. — Madagascar, Comores. HABITAT. — Under trees in humid forest at intermediate elevations; 700-1400 m.

MATERIAL STUDIED. — MADAGASCAR: Decary 12, Ambohimanga , 25 Aug. 1920 ( P!) ; Humbert & Cours 17804, Andrangovolo Massif, SE of Lake Alaotra, Res. Nat. no. 3 of Zahamena, basin of the Onibe , 1200-1400 m, Oct. 1937 ( P!) ; Perrier de la Bâthie 11880, Analamazaotra, Périnet 800 m, July 1913 ( P!) ; Perrier de la Bâthie 17740, Ambre forest , 700 m, Aug. 1926 ( P!) . — COMORES: Benson 84, Niombadjou, Grande Comore, 15 Aug. ( P!) ; Bernard s.n., M’zoudi hill, Anjouan, 27 Aug. 1903 ( P!) ; Bosser s.n., Anjouan, 1963 ( P!) ; Humblot s.n., without exact loc. ( W) ; Humblot 1592 (592), without exact loc. ( P!) .

REICHENBACH (l.c.) did not cite a number for the type specimen of this obscure species, and the flower on the sheet in the REICHENBACH herbarium in Vienna is in poor condition. However, in his protologue, REICHENBACH gave the characteristics of the lip that correspond well with the herbarium material from Madagascar and the Comores cited above under D. humblotii . He said of the lip: “lamina mediana bene unguiculata, oblonga, velutina basi superiore excepta”. This last detail is characteristic of this species. With regard to D. comorensis , we have not seen the type, Bang s.n., which was in SCHLECHTER’ S herbarium ( B) which was destroyed, but the description of the lip is sufficiently clear for us to concur that it belongs to the same species: “labello…antice tertia parte bifido, segmentis erectis, obtusis, medio antice in processum arcuatoadscendentem graciliter unguiculatum, subpeltatum, lamina carnosa, sigmoidea, utrinque obtusa papillosa ”. Although he did not mention the glabrous basal part of the terminal appendage of the lip, the term sigmoid describes its saddleshaped form. On the other hand, SCHLECHTER attributed Humblot 1592 ( P) to his D. comorensis and it is possible that the herbarium specimen of HUMBLOT found in Vienna, the type of D. humblotii , was a part of that collection.

Although there are few Madagascan collections, the distribution of the species is extensive, ranging from around Antananarivo to Périnet (Andasibe) to Lake Alaotra and Mt. Ambre. In the Comores, it has been found on Grande Comore and Anjouan but it is very local .

The flower recalls somewhat that of D. lanceana , but the terminal appendage of the lip is larger and of a diffferent form.

Figures

Fig. 6. — Appendage of lip: A, Disperis majungensis (Perrier de la Bâthie 13038); B, Disperis cordata (Cadet C11, in alcohol); C, Disperis hildebrandtii (Hildebrandt 3158); D, Disperis ciliata (Humbert & Capuron 25002); E, Disperis lanceana (Lance s.n.); F, Disperis saxicola (Bosser 17168); G, Disperis humblotii (Humblot 1592); H; Disperis perrieri (Humbert & Capuron 25758); I, Disperis oppositifolia var. mascarenensis (Bosser 21622).