Disperis discifera H. Perrier

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 : 65-67

7. Disperis discifera H. Perrier

Not. Syst. (Paris) 5: 222 (1936); in Humbert H. (ed.), Fl. Madag., 49 e fam., Orchidées 1: 184 (1939); Du Puy et al., Orch. Madag.: 134 (1999). — Type: Perrier de la Bâthie 16081, Madagascar, Mt. Tsaratanana, Apr. 1924 (lecto-, P!, selected here, photo K!) .

Slender terrestrial herb 10-30 cm high. Tubers 2, ovoid, but plants sometimes produce stolons with additional tubers at the end. Leaves 2-4, alternate, sessile, the lowest at about the middle of the stem, 2.2-6 × 0.8-2 cm, ovate or lanceolate, acute, clasping the stem at the base, purple below.

Inflorescence 1-3-flowered; bracts leaf-like, 10- 33 × 4-8 mm. Flowers clear rose pink with two lines of green or brown spots on the basal part of the hood; pedicel and ovary (12) 14-19 mm long. Dorsal sepal 8-12 × 1-2 mm, linear; lateral sepals 11-13 × 4.5-7 mm, joined for a short distance at the base, obliquely obovate, each with a sac-like spur c. 1.5 mm long. Petals 8-12 × 4-6 mm, more or less oblong or wedge-shaped, joined to the dorsal sepal to form a shallow hood, broadly rounded or truncate at the tip, concave or apiculate. Lip with a narrow claw c. 3.8 mm long, adnate to the column at the base then bent over and bearing at the tip an ovate appendage 2.8- 3 mm long, 1.5-2 mm wide, with a dense papillose yellow pubescence above, glabrous below, with a glabrous apiculus at the tip. Rostellum large, 3.5-4 × 4-6 mm, with hyaline, linear arms 2 mm long. — Fig. 7C.

DISTRIBUTION. — Madagascar; endemic. HABITAT. — In moist forest, in shade and open areas; 800-2250 m.

MATERIAL STUDIED. — MADAGASCAR: Bosser 15440, Tampoketsa, Ankazobe , May 1962 ( P!) ; Bosser 18412, Lakato road, July 1963 ( P!) ; Bosser 20253, Manjakatompo, Ankaratra , 5 May 1970 ( P!) ; Herb. Jard. Bot. Tananarive 3700, Ambatoloana , 8 June 1938 ( P!) ; Humbert 30276, massif of Ankaratra, Manjakatompo forest , 27 Apr. 1955 ( P!) ; Jongkind & Solo Rapanarivo 886, Fianarantsoa, 1 hour walking from Antoetra, in open place in disturbed natural forest on East side of hill, 1700 m, 13 May 1993 ( K!, MO, P!) ; Malcomber & Hemingway 2462, Antsiranana, E of Ambanja, Réserve Naturelle Intégrale 4 ( Tsaratanana ), 1100-1600 m, fl. 8- 12 May 1993 ( K!, MO, P!) ; Perrier de la Bâthie 16081, 16488, 16489, Mt. Tsaratanana , in dense forest c. 1400 m, May 1924 ( P!) ; Petterson & Nilson 580, Angavokely, Mt. Ambatolava , 13 Mar. 1992 ( P!, UPS) ; Rababoto in Rés. Nat. 6431, Mangindrano, Bealanana , Rés. Nat. no. 4, 15 May 1954 ( P!) ; Rakoto & Turk 62, SE of Fianarantsoa, Tolongoina FR, Parcelle A5 , 1115 m, 14 June 1992 ( K!, MO, P!) ; Rakoto & Turk 90, Fianarantsoa, Ranomafano National Park, Parcelle 1, Ambohimera , 800-1315 m, fl. 18 June 1992 ( K!, MO, P!) ; Rakotovao in Rés. Nat. 6546, Ivohibe, Rés. Nat. no. 5, 25 July 1954 ( P!) ; Rakotovao in Rés. Nat. 12109, Manakambahiny E, Ambatondrazaka , 27 June 1962 ( P!) ; Sajy in Rés. Nat. 5215, Marovato, Ambanja , Rés. Nat. no. 4, 15 Apr. 1953 ( P!) .

— Disperis discifera var. borbonica (H. Perrier) Bosser , comb. et stat. nov.

Disperis borbonica H. Perrier, Not. Syst. (Paris) 5 (3): 228 (1936). — Type: Delteil s.n., La Réunion, without exact loc. (holo-, P!).

A slender moisture-loving, terrestrial plant, 10- 30 cm tall. Leaves two, alternate, lanceolate, rounded and amplexicaul at the base, acute at the apex, sessile, 1.6-4 cm long, 0.6-2 cm wide, inserted on the middle part of the stem. Inflorescence with 1-3 flowers. Flowers pale rose with green marks at the base of the hood. Hood 6-7 × 7-8 mm, concave, rounded or subquadrate at apex. Lateral sepals 6.5-7.5(-8) mm long. Lip with an ovate-acute apical appendage, 1.5- 1.8 mm long, 1-2 mm wide, covered on its upper side by short yellow papillae, the apex with a short glabrous point. — Fig. 5.

DISTRIBUTION. — Madagascar, La Réunion.

HABITAT. — Under trees in humid forests and ericaceous scrub, in Madagascar in the Ankaratra massif it also grows in pine ( Pinus patula ) plantations; 1200-2350 m.

MATERIAL STUDIED. — MADAGASCAR: Goldblatt & Schatz 9014, Ankaratra Massif , W of Ambatolampy, 2350 m, 31 Mar. 1989 ( G!, K!, MO, P!) ; Kotozafy, Randriamantena & Randrianasolo 18, Ranomafana National park , parcelle 1, Ampasina, NE of Amboditanimena, 1200 m, 11-25 Aug. 1993 ( MO, P!) ; Perrier de la Bâthie 16487, Mt. Tsarantanana , 2200 m, Apr. 1924 ( P!) ; François in Perrier de la Bâthie 16530, la Mandraka, Feb. 1924 ( P!) . — LA RÉUNION: de Cordemoys. n., Fougères plain ( MARS, P!) ; Delteil s.n., without exact loc. ( P!) ; de l’Isle 118, Grand Bélouve ( P!) .

This variety is very similar in habit and lip morphology to the typical D. discifera , but its flowers are much smaller. The two varieties are sympatric in the Ankaratra Massif. This variety has not been found recently in La Réunion, the collections from there are all over a century old.

Figures

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).

Fig. 5. — Disperis discifera var. borbonica: A, flowering plant; B, flower and bract; C, hood, front view; D, dorsal sepal; E, lateral sepal; F, petal; G, column and lip, front view; H, column and lip side view; I, column and lip, back view; J, lip; K, pollinarium. (Goldblatt & Schatz 9014, K).