Projecting to pendulous small to moderately large, sparsely branched or tangled epiphytes with numerous relatively thin roots and thin fibrous leafy stems. The small, crowded or spaced, narrow or relatively broad leaves are arranged in 2 ranks, sometimes appearing fan-like. Inflorescences are short and sometimes branched. The small often crowded fragrant flowers face the end of the raceme and are mainly white. They have relatively narrow projecting or incurved segments and a stiffly attached labellum with a short broad spur which lacks any internal structures. The column is short without a column foot.
Similar Genera
Significant Generic Characters
Epiphytic orchids; plants small to moderately large, branched or unbranched; stems thin, fibrous; leaves crowded or well-spaced, thinly coriaceous to fleshy, in 2 ranks, sometimes fan-like, longer than wide; inflorescence a raceme or sparsely branched panicle; flowers small, often tubular, facing the raceme apex, lasting several days, fragrant; perianth segments thick-textured; sepals subsimilar; petals slightly shorter than the sepals; labellum firmly attached to the column base; lamina 3-lobed, with a basal spur; spur short, broad, without any internal callus structures; column short, without a foot, obscurely winged; pollinia 4, stalked on a stipe, in 2 unequal pairs.
Size and Distribution
A genus of about 20 species, occurring in India, China, Malaysia, Philippines, Indonesia , New Guinea and Australia where there are 2 non-endemic species. In Australia the genus is distributed disjunctly in northeastern Queensland between the Iron Range (12º38’ S) and Tully (17º56’ S). State occurrence: Queensland.
Ecology
Schoenorchis micrantha grows on shrubs and trees in lowland rainforest and mangroves, less commonly at low to moderate altitudes in the ranges. Schoenorchis sarcophylla grows on trees overhanging streams and along ridges in stunted rainforest.
Biology
Pollination: The flowers of Schoenorchis last many days and seem to be pollinated by native bees, although Schoenorchis sarcophylla may be self-pollinating.
Reproduction: Reproduction in Schoenorchis is solely from seed. Seed dispersal takes 10-12 months after pollination and the capsules develop in a porrect position. Apomixis is unknown in the genus.
Seasonal Growth: Plants of Schoenorchis grow mainly during the spring and summer months and are relatively quiescent for the remainder of the year.
Flowering: The native species of Schoenorchis flower in winter and spring.
Hybrids: Natural hybrids involving native species of Schoenorchis are unknown.
Derivation
The name Schoenorchis is derived from the Greek schoenos, reed or rush and orchis, orchid.
Botanical Description
Perennial, evergreen, epiphytic herbs, monopodial. Roots thin, elongate, straight, mostly adherent. Plants small to moderately large, sometimes in tangled clumps, porrect or pendulous. Stem short to moderately long, fibrous, sparsely to regularly branched. Pseudobulbs absent. Trichomes absent. Leaves lasting several seasons, porrect or spreading, distichous, sessile, longer than wide, narrow to relatively broad, straight or curved, flat or channelled, thinly coriaceous to fleshy, smooth; base sheathing the stem, usually persistent after leaf abscission, imbricate; margins entire. Inflorescence lateral, racemose or paniculate, arcuate or pendulous, multiflowered. Peduncle shorter or longer than the rhachis, thin to thick, with few imbricate scarious bracts. Rhachis straight. Floral bracts scarious, sheathing the base of the pedicel. Pedicel short, thin, merging with the ovary. Ovary short, straight. Flowers resupinate, small, often tubular, shortly stalked, facing towards the inflorescence apex, opening sequentially, lasting several days, white, fragrant. Perianth segments moderately thin-textured, porrect to incurved. Dorsal sepal free, subsimilar to the lateral sepals. Lateral sepals free, subsimilar to the dorsal sepal, flanking the labellum. Petals free, slightly smaller than the sepals. Labellum stiffly attached to the base of the column, markedly dissimilar in size and shape to the sepals and petals, calcarate. Labellum lamina fleshy, with a basal spur, 3-lobed; spur sort and broad, widest near the middle, without any internal callus structures (sometimes obscure wall thickenings are present); lateral lobes short, broad, free, flanking the column; midlobe relatively long, fleshy. Spur present (see above). Callus absent or obscure. Nectar present (?). Column short, porrect from the apex of the ovary, lacking free filament and style, fleshy, nearly straight. Column wings obscure,short, narrow. Column foot absent. Pseudospur absent. Anther terminal, incumbent, 2-celled, persistent, smooth, with a narrow curved rostrum. Pollinarium present. Pollinia 4 in 2 appressed pairs, unequal, orange, hard, waxy, attached to the stipe by short stalks. Stipe well-developed, long, narrow. Viscidium present, relatively large, at an angle to the stipe Rostellum ventral, elongate, triangular, bifid. Stigma basal, entire, concave. Capsules dehiscent, glabrous, porrect; peduncle not elongated in fruit; pedicel not elongated in fruit. Seeds numerous, light coloured, winged.
Taxonomy
Within the Vandeae, Schoenorchis is distinguished by the racemose or paniculate inflorescence, small often tubular flowers facing the raceme apex, 3-lobed labellum with a short broad spur that lacks any internal callus structures, short obscurely winged column without a foot and, 4 stalked pollinia in 2 unequal pairs.
Nomenclature
Schoenorchis Blume, Bijdr. 6: t.3, fig. 23; 8: 361 (1825).
Type species: Schoenorchis juncifolia Blume.
Infrageneric Taxa: No infrageneric taxa are currently recognised.
References
Dockrill, A.W. (1967). Australasian Sarcanthinae. The Australasian Native Orchid Society, Sydney.
Dockrill, A.W. (1969). Australian Indigenous Orchids. Volume 1. The Society for Growing Australian Plants, Halstead Press, Sydney.
Dockrill, A.W. (1992). Australian Indigenous Orchids. Volume 1 & 2. Surrey Beatty & Sons in association with The Society for Growing Australian Plants, Chipping Norton, NSW.