Apostasia wallichii

Apostasia wallichii R.Br. in Wall., Pl. Asiat. Rar. 1 (1830) 75, pl. 84

Type: Wallich 4448 (Nepal, Noakote) (lecto K-WALL; iso E, K)

Herb, 10-l00 cm high. Aerial roots emerging from between the lower leaves and the cataphylls, 0.05-0.5 cm diam. Rooting part of the stem 0.2-0.35 mm diam. Cataphylls 0.2-1 cm long, 5-15-nerved. Leaves closely set, linear, 10-50 by 0.3-1.8(-2) cm, acute (filiform tip up to 2 cm); margin entire or minutely dentate and glandular (hand-lens); 15-60-nerved, 3 or 5 of which are more prominent; sheath not marked. Inflorescences pendent, sometimes more or less erect, with 1-6 side-branches; 5-2(-30) flowers along each branch. Bracts triangular to lanceolate, acute (usually the lower with a filiform tip up to 0.05 (-0.09) cm), margin as that of the leaves, 0.1-0.2(-2.4) cm long, (1-)3-7(-10)-nerved. Ovary 1-2.2 by 0.1-0.2 cm. Flowers 1-2.2(-2.7) cm long. Sepals 0.4-0.65 by 0.06-0.17 cm, 3-5(-7)-nerved, cusp 0.04-0.12(-0.17) by 0.01-0.02 cm. Petals and lip 0.37-0.6 by 0.05-0.15 cm, (1-)3(-5)-nerved, cusp 0.02-0.08(-0.12) by 0.01 cm, the lip sometimes broader and more convex. Column straight to strongly curved, 0.07-0.15(-0.18) by 0.02-0.06(-0.07) cm. Stamens (0.2-)0.3-0.4(-0.5) by 0.06-0.1 cm; free part of the filaments 0.05-0.1 by 0.02-0.025 cm; anthers with an unequally bilobed to (oblique) entire tip; the longer anther cell opposite the staminode 0.01-0.04(-0.1) cm longer at the base and up to 0.05 cm longer at the apex; the shorter anther cell free from the longer one by 0-0.03 cm at the tip. In specimens from Sri Lanka the base of the anthers may be equal, or the loculus facing the staminode may be slightly longer. Staminode 0.13-0.3(-0.4) by 0.02-0.06 cm; entirely adnate or with an obtuse tip up to 0.1 cm free. Free part of the style straight, occasionally curved, 0.25-0.48 by 0.02-0.05 cm, sometimes irregularly longitudinally ribbed, mostly overtopping the anthers by up to 0.04 cm, but sometimes overtopped by the anthers by up to 0.06 cm. Stigma 2-3-lobed, sometimes suborbicular. Fruit 1.2-2.5 by 0.14-0.2 mm. Seeds alveolar to nearly smooth. (After de Vogel, 1969).

Colours: Flowers yellow, rarely whitish.

Habitat: Undergrowth of primary forest, sometimes along streams. Altitude (20-) 250 to 1200 (-1700) m.

Flowering time in the wild: January

Distribution: Sri Lanka, Nepal, India (Assam), Burma, Thailand, Cambodia, Laos, Vietnam, Peninsular Malaysia, Sumatra, Java, Borneo, Celebes, Moluccas, New Guinea, Philippines, Australia (Queensland).

Distribution in New Guinea: Papua (Indonesia); Papua New Guinea. See map: 56-21M.JPG

Cultivation: Warm growing terrestrial, keep in shade in humus-rich soil, well-watered throughout the year. Apparently very difficult to grow, as various attempts to introduce it into cultivation at the Hortus Botanicus at Leiden have all met with failure.

Note: Apart from the few species of Paphiopedilum this is the only orchid in New Guinea with two fertile anthers. It differs from Paphiopedilum in the plicate, not distichous leaves, well-developed stems and much simpler flowers without a slipper-shaped lip.