Acriopsis liliifolia

Acriopsis liliifolia (J.Koenig) Ormerod, Opera Bot. 124 (1995) 58

Basionym: Epidendrum liliifolium

Plants entirely glabrous except the lip sometimes somewhat hairy, 16-115 cm high. Main roots 0.1-0.35 cm diam., catch roots 0.03-0.15 cm diam. Rhizome 0.2-0.6 cm diam., between the pseudobulbs with 3-5 internodes 0.2-0.7 cm long; scales 0.5-1 cm long, often eroded. Pseudobulb scales 3-4, 1.5-7 cm long. Pseudobulbs 0.5-2.5 cm apart, 1.3-6 by 1-3 cm, with 5-7 internodes, (2-)3-4-leaved. Leaves petiolate, petiole 1.5-2.5 cm long; blade linear, 5-28 by 0.3-2 cm, apex acute to obtuse, sometimes with a small acumen. Panicle 12-200-flowered, erect or drooping, 16-90 cm long, curved at the tip; basal scales appressed, 3-5, 0.4-1.7 cm long; peduncle 8.5-55 cm long, 0.1-0.35 cm diam., with 2-4 internodes; peduncle scales appressed, 0.4-1.6 cm long; rachis 8-38 cm long; branches 0-7, to 25 cm long, sometimes with secondary branches. Floral bracts 0.15-0.3 by 0.05-0.15 cm. Pedicel 0.3-0.64 cm long, c. 0.04 cm diam., ovary 0.2-0.35 cm long. Flowers 0.2-4 cm apart, 0.8-1.4 cm diam. Median sepal 0.47-0.72 by 0.1-0.28 cm; apex acute, nerves 3. Synsepalum 0.45-0.65 by 0.14-0.32 cm; apex obtuse; nerves 4-6. Petals oblong to obovate, 0.43-0.68 by 0.15-0.3 cm; apex rounded; nerves 3 or 5. Lip 3-lobed. Hypochilium: adnate part 0.21-0.3 cm long, sometimes slightly inflated, centrally constricted; basal outgrowth c. 0.04 cm from the base of the column, 0.05-0.17 cm long, patent to deflexed; free part narrowed, more or less canaliculate, 0.09-0.16 by 0.08-0.15 cm, apically without marginal auricles. Epichilium 0.38-0.5 by 0.25-0.5 cm, from base to keel centrally slightly swollen; lateral lobes obovate, triangular or obliquely rectangular, spreading or bent forwards, 0.1-0.2 by 0.14-0.22 cm, slightly convex, tips rounded to obtuse; glabrous or sometimes with very short hairs; end-lobe obovate with a broad base to spathulate, 0.14-0.31 by 0.06-0.14 cm, apex rounded to slightly emarginate, deflexed, glabrous; keels on the base of the end-lobe, erect to ascending, 0.06-0.13 by 0.04-0.06 cm, tips rounded to truncate, sometimes slightly papillose. Column almost straight, 0.38-0.6 cm long; stelidia 0.09-0.15 cm long, 0.03-0.05 cm diam., tips swollen, decurved; hood straight, 0.09-0.15 cm long, not constricted, its top margin not recurved, entire, emarginate or slightly crenulate. Stigma elliptic in outline, sometimes slightly elevated; rostellum beak-like or narrowly triangular, 0.09-0.13 cm long. Anther more or less pear-shaped, 0.06-0.1 by 0.03-0.04 by 0.03-0.05 cm. Pollinia more or less falcate and flattened or obovoid, the inner two narrower, 0.07 by 0.02-0.03 cm; tips rounded to acute; stipes 0.06-0.07 cm long; viscidium more or less ovate, 0.01-0.015 by 0.01 cm. Fruit ellipsoid to globose, 0.9-1.5 by 0.8-1 cm. (After Minderhoud & de Vogel, 1986).

Colours: Sepals and petals greenish white to cream-coloured; sepals with a purple blotch at the tip and a more or less outstretched median purple stain, petals with purple markings varying from a longitudinal median purple stripe to only an apical purple spot. Lip cream-coloured; free part of the hypochilium purple-stained; lateral lobes with a more or less clear purple centre; end-lobe centrally purple with purple keels. Column purplish brown with purple stelidia tipped shiny yellow. Hood and rostellum greenish white, pollinia yellow. Leaves and pseudobulbs shiny apple-green, inflorescence stalk green; peduncle scales and (floral) bracts more or less transparent with a purplish median stripe, pedicels lighter green, ovaries somewhat darker. In New Guinea besides the common form with purple markings, a lighter form with pale yellow flowers with a purplish centred lip and a green column occurs. Also entirely cream-coloured flowers occur there. Both forms occur throughout the island.

Habitat: Locally common epiphyte, in primary rain forest, savanna, mangroves, coastal swamp forest (on Melaleuca leucadendron and Pandanus species) and freshwater forest, often on dead wood, also in plantations, once on tufts of grass at the shore (in Peninsular Malaysia: Kuala Pahang), sometimes lithophytic (New Guinea) or terrestrial in white sand (in Borneo: Sarawak); in Australia, Cape York Peninsula, often on exposed sites on paperbarks. Altitude 0-1600 m.

Flowering time in the wild: January, February, March, May, July, September, October, December.

Distribution: Malesia (Peninsular Malaysia, Singapore, Sumatra, Java, Borneo, Sulawesi, Lesser Sunda Islands, Moluccas, New Guinea, The Philippines), Thailand, Vietnam, ?Sikkim, Australia, Solomon Islands.

Distribution in New Guinea: Papua (Indonesia); Papua New Guinea. See map: 9-17M.JPG

Cultivation: Warm to intermediate growing epiphyte, keep in light position.

Note: An easily recognised and common species with short fat pseudobulbs and slender, much-branched inflorescences carrying quite small flowers. The only other orchid in New Guinea that is vaguely similar in this respect is the unrelated Ridleyella paniculata, which differs in many ways, for example in the free lateral sepals. Specimens in New Guinea often, but not always, have much paler coloured flowers than those occurring in the western part of the distribution area.