Cadetia chamaephytum

Cadetia chamaephytum (Schltr.) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 428.

Basionym: Dendrobium chamaephytum.

Roots to more than 8 cm long, 0.5-1 mm diameter. Rhizome very short. Pseudobulbs crowded, cylindrical, weakly 4-ribbed, 5-12 mm long, 2-3 mm diameter. (usually much thinner in dried specimens: 1-1.5 mm). Leaf linear-oblong to narrowly ovate, index 2.3-5, 9-14 by 2-4 mm, base cuneate to subpetiolate, apex obtuse, apiculate. Inflorescences terminal from the leaf axil and subterminal just below the abaxial side of the leaf, solitary, rarely 2 in succession from the same position, at the base with a c. 2 mm long tubular basal bract. Peduncle c. 4 mm long. Ovary and pedicel 12-17 mm long, 3-winged, glabrous. Flower c. 1 cm across. Median sepal reflexed, elliptic-ovate, 5-5.3 by c. 2.5 mm, obtuse to subacute, 3-nerved. Lateral sepals patent, elliptic-ovate, slightly oblique, 5.1-5.3 by c. 2.8 mm, 3-nerved, obtuse to subacute; mentum conical, straight, 2.2-3.5 mm long, apical closed part c. 1.5 mm, apex rounded. Petals porrect, broadly lanceolate, 4.5-4.7 by 2.3-2.5 mm, margin undulate (always?), entire or minutely crenulate, 3-nerved, apex obtuse to subacute. Lip subspathulate, weakly 3-lobed, glabrous, except for papillose-pubescent exterior of hypochile; callus usually indistinct, oblong, glabrous, extending from the apex of the hypochile to below the apex of the midlobe, entire; hypochile 3-3.4 mm long, of which c. 0.8 mm fused with the column foot, 0.9-1.3 mm wide across the flattened lateral lobes; lateral lobes very small, obliquely broadly elliptic to obliquely triangular, 0.2-0.4 mm long, entire, apex rounded to subacute; midlobe ovate to elliptic-ovate, 1.5-2.9 by 1-1.6 mm, very fleshy, entire, narrowed to the apex, obtuse to subacute. Column 1.2-1.8 mm long, pubescent in front below the stigma, wings rectangular, obscurely bidentate, clinandrium entire, with a narrow triangular median tooth; foot 2.2-3.5 mm long, pubescent at the base. Anther cucullate, c. 0.8 by 0.8 mm, base emarginate; apex truncate, pubescent-papillose; pollinia 0.7 mm long. Fruit ovoid, c. 10 by 4 mm, 3-angular in cross-section.

Colours: Flower pure white.

Habitat: Epiphyte in primary lower montane forest. Altitude 600 to 1200 m.

Flowering time in the wild: April, June, September, November.

Distribution: Moluccas (Ambon), New Guinea.

Distribution in New Guinea: Papua (Jaya Wijaya and Jayapura Regencies); Papua New Guinea (Sandaun and Morobe Provinces).

Map: CHAPHMAP.JPG [Cadetia chamaephytum (Schltr.) Schltr., distribution map.]

Notes: Cadetia chamaephytum is closely related to Cadetia imitans, from which it may be distinguished by its short mentum, which is at least 5 mm long in the latter. C. chamaephytum varies to some extent in the shape of the lateral lobes and in other minor characters; this is reflected in the synonymy. The altitude given by Mansfeld for C. chamaephytum, 3000 m, is almost certainly erroneous. The material he cites was collected by Keysser in the Sarawaket range. It seems that many of Keysser's specimens were routinely labelled as being collected at 3000 m altitude, even though they were in reality found at much lower elevations (e.g. Mansfeld's records of Dendrochilum longifolium and Appendicula flaccida are equally suspect as to the stated altitude of 3000 m). It follows that this species was wrongly included in the Alpine Flora of New Guinea by van Royen (1979).

Cultivation: Intermediate growing epiphyte.