Cadetia chionantha

Cadetia chionantha (Schltr.) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 429.

Basionym: Dendrobium chionanthum.

Roots to more than 10 cm long, 1 mm diameter. Rhizome very short. Pseudobulbs crowded, narrowly cylindrical, weakly 4-ribbed (ribs often more pronounced in dried specimens), 1.3-4 cm long, 1-2 mm diameter. Leaf linear-elliptic, 1.2-3(-4) cm by 2-3.5 mm, base gradually narrowed, apex obtuse, minutely bilobulate, mucronate, mucro longer than lobules. Inflorescences terminal from the leaf axil and subterminal just below the abaxial side of the leaf, solitary, at the base with a 2-3 mm long tubular sheath widened near its apex. Peduncle c. 2 mm long. Ovary and pedicel 10-28 mm long, 6-winged, glabrous. Flower c. 0.8 cm across. Median sepal patent, ovate, 3.0-4.7 by 1.7-2.6 mm, obtuse to subacute, 1-3-nerved. Lateral sepals patent, broadly obliquely ovate, 3.5-4.6 by 2.7-3.1 mm, obtuse, 3-nerved; mentum conico-cylindrical, straight, 1.9-2.7 mm long, apical closed part 1.7-1.9 mm, apex rounded to obscurely bilobed. Petals subpatent, lanceolate to linear-lanceolate, 2.8-4.4 by 0.6-1.0 mm, entire, obtuse to acute, 1-nerved. Lip spathulate, obscurely 3-lobed, 6.8-10.7 by 2-3.9 mm, papillose inside, minutely pubescent on outside of claw; claw linear, 2.0-3.3 by 1.1-1.4 mm; blade 2.8-3.5 by 2.9-4.1 mm; lateral lobes triangular, 0.4-0.5 by 0.4 mm, entire, obtuse; midlobe broadly obcuneate, 2.0-3.9 by 2.9-4.1 mm, entire, fleshy, apex emarginate, usually with an obtuse to acute mucro in the sinus; callus at base of midlobe triangular, 3-5-ribbed, rarely callus indistinct. Column 1.6-1.9 mm long, subglabrous, wings oblong, truncate, obscurely denticulate, clinandrium entire, with a narrowly triangular median tooth; foot 1.9-2.7 mm long. Anther cucullate, 0.9 by 0.9 mm, glabrous; pollinia 0.8 mm long. Fruit ovoid, c. 10 by 4-5 mm, 3-winged with 3 additional low ribs.

Colours: Leaves shiny dark green above, paler green below. Flower pure white, lip often more creamy white, callus often greenish.

Habitat: Epiphyte on mossy tree trunks and branches in primary and disturbed montane forest, rarely on tree fern trunks at the edge of tree fern grassland. Altitude 1300 to 2400 m.

Flowering time in the wild: Throughout the year.

Distribution: New Guinea, Bismarck Archipelago, Louisiades.

Distribution in New Guinea: Papua (Jaya Wijaya Regency); Papua New Guinea (Sandaun, Southern Highlands, Enga, Western Highlands, Simbu, Eastern Highlands, Morobe, Central and Milne Bay Provinces, also in New Ireland and the Louisiades).

Map: CHIONMAP.JPG [Cadetia chionantha (Schltr.) Schltr., distribution map.]

Notes: Cadetia chionantha, one of the more common species of Cadetia in the highlands of New Guinea, may be recognized by the broadly obcuneate, emarginate midlobe of the lip, in combination with the small, almost tooth-like sidelobes. In most specimens the callus is well-developed, in some it is indistinct.

Closely related, possibly conspecific, are Cadetia cuneilabia Schltr. and Cadetia sayeri Schltr., which at present are only known from the descriptions, all material being lost.

Cultivation: Cool growing epiphyte, requires light shade and excellent drainage, but strongly resents drying out for any considerable length of time.