Filigree Orchids
A genus with one endemic species occurring in Australia, receive their common name, filigree orchids, from the ornate spidery network of veins on the leaves. Anchored by wiry roots that appear woolly, these terrestrial orchids have succulent above-ground creeping rhizomes. They grow in sheltered positions in the rain forest, usually amongst the litter on the rain forest floor making it difficult to see them. The stalked, short, broad, velvety leaves, which arise in a basal rosette, are dark green or brownish purple often with silvery, coppery or red veins. The unbranched terminal inflorescence is short and on a hairy shoot. The relatively large showy flowers, ranging from 1-15 cm in width, are dull in colour (sepals green with brownish markings, petals and labellum white), hairy and often short-lived. The dorsal sepal and petals overlap to form a hood, with the lateral sepals free. The labellum has incurved fringed margins that expand into a notched apex. Anoechochilus occur in northern Queensland and flower between July and September.
Similar Genera
Rhomboda
Significant Generic Characters
Terrestrial orchids, evergreen or deciduous; rhizomes succulent, above-ground, creeping with an erect apex, anchored by wiry nodal roots that appear woolly; leaves petiolate, in a basal rosette, relatively broad, thin-textured, dark green or brownish purple, often with colourful silvery, coppery or red veins; inflorescence spicate, short, terminal on a shoot; flowers resupinate (rarely non-resupinate, non-Australian), relatively large, often short-lived, dull-coloured (green, brown, white or pinkish), externally hairy; perianth segments narrow; dorsal sepal and petals overlapping to form a galea; lateral sepals divergent. Labellum attached to the anterior margins of the column base, with a protruding basal spur (rarely absent); hypochile longer than the epichile; epichile with a narrow basal claw and expanded lamina, the base with spreading teeth or long thin lobes forming a fringe; apex entire or cleft constricted into a narrow central region with incurved margins, this region fringed with spreading teeth or thin lobes, then expanded into a blade with entire or recurved margins or a notched apex. Basal spur cylindrical, with 2 large stalkless glands. Column short, winged. Stigmas 2.
Size and Distribution
A genus of about 30 species distributed in tropical and warm temperate regions from India, Sri Lanka and Japan south to Malaysia and east to New Guinea, Australia and some Pacific Islands. A single endemic species, Anoectochilus yatesiae, occurs in northeastern Queensland, more or less between Thornton Peak (16°11' S) and the Paluma Range (19° S). State occurrence: Queensland.
Ecology
Anoectochilus yatesiae grows in sheltered positions in rainforest, usually amongst litter on the rainforest floor. It is often found in gullies close to small streams and in accumulations of litter on rocks and in pads of moss. It usually grows in dark areas where there is high humidity. Occasionally plants are found on sheltered embankments and road verges. Elevation ranges from about 500 m to 1200 m alt. The climate has a summer wet season (December to March) with the remaining months being much drier with sporadic or intermittent rain.
Biology
Pollination: The flowers of Anoectochilus yatesiae are self-pollinating.
Reproduction: Anoectochilus yatesiae reproduces solely from seed. Seed dispersal takes 3-4 months from pollination and the capsules develop in an erect position. There is no elongation of the peduncle or pedicels. Apomixis is unknown in the genus.
Seasonal Growth: Anoectochilus yatesiae survives the dry parts of the year as leafy or leafless quiescent plants.
Flowering: Anoectochilus yatesiae flowers between July and September.
Hybrids: Anoectochilus yatesiae does not participate in natural hybridisation.
Fire: Anoectochilus yatesiae does not grow in fire-prone habitats.
Derivation
Anoectochilus is derived from the Greek, anoectos, open and cheilos, lip, in reference to the labellum base being adnate to the column but with spreading apical lobes.
Botanical Description
Perennial, evergreen or deciduous, terrestrial herbs, sympodial. Roots wiry, produced from stem nodes, appearing woolly from a covering of root hairs. Rhizomes cylindrical, fleshy, sparsely branched, prostrate with an erect apex, usually 1 shoot per plant. Stem erect, short, fleshy, apical. Pseudobulbs absent. Trichomes present on peduncle, rhachis, bracts, ovaries and exterior of the sepals, unbranched, multiseriate, glandular and eglandular. Leaves lasting 1-2 seasons, few per shoot, glabrous, with a distinct petiole, sheathing at the base, forming a loose basal rosette. Leaf lamina broad, thin, membranaceous, flat, smooth, entire, usually dark-coloured, often with silvery, reddish or coppery main veins. Venation acrodromous to campylodromous, with numerous cross-veinlets and few anastomoses. Inflorescence spicate, terminal on a growth, few-flowered, erect. Peduncle much longer than the rhachis, hirsute, with semi-sheathing to projecting, hirsute sterile bracts. Floral bracts sheathing, hirsute. Ovary elongate, asymmetric, straight or curved, hirsute. Flowers resupinate (rarely non-resupinate, non-Australian), crowded, opening tardily, dull coloured (sepals green with brownish markings, petals and labellum white), hairy, sessile to subsessile. Dorsal sepal closely overlapping with the petals to form a galea, narrow, externally hirsute, margins incurved. Lateral sepals free, narrow, externally hirsute, often widely divergent. Petals of similar length to the sepals, forming a galea with the dorsal sepal, asymmetric, membranous. Labellum fixed by its base to the anterior column base, immoveable, markedly dissimilar in size and shape to the sepals and petals, calcarate (rarely ecalcarate). Labellum lamina divided into a hypochile and an epichile; hypochile longer than the epichile, entire, with an exserted cylindrical basal spur containing 2 large stalkless glands; epichile with a narrow basal claw and expanded lamina, the claw with spreading pectinate teeth or long thin lobes forming a fringe; distal margins entire, recurved; apex entire or cleft. Callus obscure. Nectar absent. Column lacking free filament and style, elongated. Column wings present, vestigial or well-developed and extending the length of the column with the base protruding into the spur. Column foot absent. Pseudospur absent. Anther dorsal, 2-celled, persistent, basifixed, with an elongated narrow rostrum. Pollinarium present or absent. Pollinia 2, hemispherical, curved, yellow, sectile, with a common stipe as long as or longer than the pollinia. Viscidium small, ovate (sometimes absent). Rostellum ventral, long and narrow. Stigmas 2, flanking the rostellum on the apical corners of the column. Capsules dehiscent, hirsute, erect; peduncle not elongated in fruit; pedicels not elongated in fruit. Seeds numerous, light coloured, winged.
Taxonomy
Within the Goodyerinae, Anoectochilus is distinguished by green to brownish or blackish velvety leaves with brightly coloured veins; resupinate hirsute flowers; labellum base with a prominent cylindrical spur, central margins of labellum with toothed or fringed margins and column winged, with 2 stigmas.
Notes
Plants of Anoectochilus yatesiae are difficult to discern from the litter and in the dark situations where they grow.
Nomenclature
Anoectochilus Blume, Bijdr. 8: 411, t.15 (1825) (nom. et orth. cons.). Type species: Anoectochilus setaceus (Blume) Lindl.,
(Anecochilus Blume, nom. illeg. - type cons.) (Anecochilus setaceus Blume – nom. rej.).
Infrageneric Taxa: No infrageneric taxa are recognised.
References
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.
Pridgeon, A.M., Cribb, P.J., Chase, M.W. and Rasmussen, F.N. (eds), (2003). Genera Orchidacearum, Vol. 3.