Disperis saxicola Schltr., 2002

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 : 72-73

12. Disperis saxicola Schltr.

Feddes Repert. Spec. Nov. Regni Veg. Beih. 33: 110 (1925); H. Perrier in Humbert H. (ed.) , Fl. Madag., 49 e fam., Orchidées 1: 189 (1939); Du Puy et al., Orch. Madag.: 136 (1999). — Type: Perrier de la Bâthie 12650, Madagascar: on Itomampy, 700 m, basin of Mananara , June 1919 (iso-, P!, photo K!) .

Terrestrial herb 6-25 cm high; tubers 2, elongate. Leaves 3, alternate, the lowest just above the middle of the stem, the lamina 2.4-6 × 1- 2.8 cm, ovate, acute, rounded to subcordate at the base, upper leaves amplexicaul, the basal with a short petiole c. 3 mm long that forms a sheath round the stem 6-7 mm long. Inflorescence 2-5- flowered; bracts lanceolate or ovate, acute, up to 10 mm long. Flowers purplish or pink; ovary and pedicel 7-9 mm long. Dorsal sepal 8 mm long, narrowly linear; lateral sepals free to the base, 8-11 × 5 mm, obliquely elliptic, each with a sac-like spur at about the middle. Petals 5-8 × 2-3.2 mm, adnate to the dorsal sepal and forming an oblong hood 6-8 mm high, 4.5 mm wide. Lip joined to the column for 2 mm, the margin more or less dilated on each side to form 2 lobes, the free part suddenly enlarged into a heart-shaped lamina 3 mm high and wide, papillose pubescent towards the top but glabrous at the base, with a glabrous stipe arising from the sinus on the anterior side bearing a kidneyshaped appendage 1.5-2,5 mm long, papillose pubescent on upper surface, slightly recurved. Rostellum broad with 2 short arms c. 1 mm long. — Figs. 6F , 7B.

DISTRIBUTION. — Madagascar; endemic. HABITAT. — In humus in dense forest, and among shaded rocks; 400-1000 m.

MATERIAL STUDIED. — CE MADAGASCAR: Benoist 1131, Périnet, Sep. 1951 ( P!) ; Bosser 17168, “Chutes de la mort”, road Moramanga to Anosibe, Aug. 1963 ( P!) ; Catat 4284, without loc. ( P!) ; Decary 5054, Vondrozo, Farafangana Prov. , 3 Sep. 1924 ( P!) ; Decary 14228, 14260, 14294, Sakaleona valley , 13-14 June 1939 ( P!) ; Decary 18016, Beforona 10 July 1942 ( P!) ; Humbert, Capuron & Cours 24813bis, Anjanaharibe, W Andapa , Dec. 1950 – Jan. 1951 ( P!) ; Lantz, Mpasimbolabe, July 1881 ( P!) ; Perrier de la Bâthie 12650, Itomanpy valley , June 1919 ( P!) ; Rés. Nat. 6546bis, Ivohibe, RN 5, July 1954 ( P!) .

The type of D. saxicola, Perrier de la Bâthie 12650 in P, comprises two specimens, on one of which, PERRIER DE LA BÂTHIE has noted “ type of SCHLECHTER”. Both are very young plants in which the flowers are in bud. But SCHLECHTER, in his protologue, described an expanded flower the characters of which are not observable in the two specimens on the P sheet. Therefore, it seems probable that there was another specimen in Berlin that has subsequently disappeared or been destroyed. The two specimens in P should be considered as isotypes .

The herbarium specimens that PERRIER DE LA BÂTHIE attributed to this species agree well with SCHLECHTER’ s protologue. The species is very close to D. humblotii in its habit, leaves, stature and the form of its flowers. However, in D. saxicola the two lateral sepals are free almost to the base and the shape of the terminal appendage of the lip is slightly different. Disperis saxicola also approaches D. lanceolata in its habit, but the latter has very small and narrow leaves that are not markedly petiolate.

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).

Fig. 7. — Flowers of Disperis species: A, D. hildebrandtii; B, D. saxicola; C, D. discifera; D, D. oppositifolia var. oppositifolia; E, D. oppositifolia var. mascarenensis; F, D. masoalensis. (A, D, F, photos J.-N. LABAT; B, C, E, photos J. BOSSER).