AFRICAN

ORCHIDS

Subtribe Cymbidiinae Benth., J. Linn. Soc. Bot., 18, 287 (1881).

Type: Cymbidium Sw.

Description:

Epiphytic, lithophytic or terrestrial herbs, with vegetative growth from base or lower nodes of persistent pseudobulb, which is usually produced annually but may grow indeterminately for two or occasionally many more years; autotrophic or rarely mycoheterotrophic. Stem pseudobulbous and ovoid to spindle-shaped, often inconspicuous and concealed within leaf bases, occasionally cylindrical. Roots velamen-covered, branching, usually arising from the base of the new growth, sometimes with erect, pointed, litter-gathering roots arising from the spreading ones. Cataphylls, if present, several, surrounding young growth, often becoming scarious and fi brous with age.

Leaves coriaceous, plicate or conduplicate, distichous, linear-elliptic or narrowly ligulate to elliptic, acuminate to strongly bilobed at apex, articulated to their persistent, broadly sheathing bases close to the pseudobulb. Infl orescences racemose, usually arising laterally from within cataphylls but occasionally from within leaf axils; peduncle erect, arching or pendulous, usually covered with infl ated, cymbiform sheaths. Flowers often showy and sometimes fragrant, subtended by persistent bracts. Sepals and petals free, subsimilar, often spreading, rarely refl exed or with petals porrect and covering column.

Labellum trilobed or rarely convex, free or fused at base to base of column for 3–6 mm, side lobes erect and weakly clasping column, midlobe often recurved; callus usually two parallel ridges and swollen toward apex, sometimes broken in middle, convergent toward apices or reduced to a pair of swellings at base of midlobe, rarely absent and replaced by a glistening shallow depression or fused into a single cuneate ridge.

Column arcuate, winged or less commonly with two lateral elongate arms, semiterete in cross-section, concave ventrally, column foot absent; pollinia usually two, deeply cleft but sometimes four in two unequal pairs, triangular, quadrangular, ovoid or club-shaped, subsessile and attached by elastic caudicles to a usually triangular viscidium with lower corners usually drawn out into thread-like appendages.

Capsule fusiform to ellipsoidal or oblong-ellipsoidal, narrowing at base to pedicel and at apex to a beak formed by persistent column.

Distribtiuon:

The subtribe comprises eight genera, six distributed from the northwestern Himalaya to Japan and south through Indo–China and Malesia to the Philippines, New Guinea, and Australia. Ansellia is endemic to Africa south of the Sahara, and Imerinaea is endemic to Madagascar.