Family Orchidaceae Subfamily Apostasioideae

Family Orchidaceae Subfamily Apostasioideae

Apostasioideae Garay in Bot. Mus. Leafl. 19: 86 (1960). Type species: Apostasia odorata Blume.

Small to large terrestrial herbs. Rhizome with scale leaves or rhizome absent. Roots usually partly aerial and stilt-like, penetrating the base of the lower leaves or rhizome-scales (where present) or both, usually pressed against the lower part of the stem or rhizome, terete, longitudinally grooved or ribbed; subterranean portion branched , sometimes with root hairs, in Apostasia with small swollen tuber-like thickenings. Stems erect or ascending, branched or simple, terete to irregularly angular or ribbed. Leaves spirally arranged, convolute, not articulate, linear, oblong to ovate-oblong, narrowly elliptic or ovate-elliptic, in Neuwiedia plicate; apex acuminate; glabrous or with scattered hairs; underside with prominent nerves; herbaceous to papyraceous. Inflorescences erect, terminal, simple or branched; rachis glabrous or hirsute; with peduncle; floral bracts leafy, persistent, glabrous or hirsute. Flowers resupinate or not, only slightly zygomorphic, small to medium size; pedicel and ovary cylindrical or ellipsoid, 3-angled to terete, not twisted, 3-celled, with axillary placentation. Sepals 3, free; median sepal very similar to the lateral ones; midrib forming a thick ridge terminating in a subulate cusp overtopping the incurved apical margin. Petals 2, free, sometimes attenuate towards the base; midrib forming a thick, fleshy, projecting keel on the outside separated from the underlying tissue by a constriction and terminating in a free subulate cusp overtopping the incurved apical margin. Lip very similar to the other petals but sometimes broader, without further ornamentation. Column straight to strongly curved , formed by the fusion of the lower portion of the style, the base of the filaments, and the staminode (in some species of Apostasia), smooth, glabrous; stamens 2 (Apostasia) or 3 (Neuwiedia), the filaments apically partly free from the style, the anthers with 2 equal or unequal thecae, 2-locular, dorsifix or sub-basifix, introrse; staminode (in some species of Apostasia) median, adnate to the style; pollen in monads, powdery; free style portion terete, cylindrical, fleshy; stigma terminal, slightly swollen, rounded or pyramid-shaped, sometimes 2- to 3-lobed, the apex flattened. Fruit 3-locular, thin- walled or rarely fleshy, disintegrating or (in one species) opening with three valves; seeds rather numerous, not dust-like, ovoid to elliptic, usually on a shorter or longer stalk, in Neuwiedia apically provided with a minute appendage, which (in 2 species) is very long or thick; testa in Apostasia dark brown when ripe, usually alveolate or reticulate, sticky when dry.
(after Wood 1999)


Subfamily Apostasioideae consists of 2 genera distributed in Sri Lanka, north-east India, Nepal, Bhutan, Myanmar, Thailand, Vietnam, Laos, Cambodia, southern China (including Hainan, Hong Kong), Japan (including the Ryukyu Islands), Malaysia, Brunei, Indonesia, the Philippines, New Guinea, Solomon Islands, Vanuatu, and northern Australia (Queensland).

  • Dressler, R. L. 1993. Phylogeny and classification of the orchid family (1993).
  • Garay, L. A. On the origin of the Orchidaceae. Bot. Museum Leafl. 19 (1960) 57-96.
  • Seidenfaden, G. The Orchids of Indochina. Opera Botanica 114 (1992) 1-502.
  • Vogel, E. F. de. Monograph of the tribe Apostasieae (Orchidaceae). Blumea 17 (1969) 313-50.
  • Wood, J.J., Beaman, R.S. & Beaman, J.H. The plants of Mt. Kinabalu. Vol. 2. Orchids (1993).
  • Wood, J.J. & Cribb, P.J. A checklist of the orchids of Borneo (1994).
  • Wood, J.J. Subfamily Apostasioideae, in Pridgeon, A.M., P.J. Cribb, M.W. Chase & F.N. Rasmussen (edit.), Genera Orchidacearum Vol. 1, General Introduction, Apostasioifeae, Cypripedioideae (2001) 94.
  • Family Orchidaceae
  • Subfamily Apostasioideae

Subfamily Apostasioideae in New Guinea contains 2 genera, Neuwiedia and Apostasia, each with 1 species

ARTIFICIAL KEY TO THE GENERA OF SUBFAMILY APOSTASIOIDEAE IN NEW GUINEA

1a. Stamens 3; anthers free from each-other. Inflorescence unbranched, erect. Ovary and fruit long-ellipsoid to rounded, strongly contracted and beak-like at the apex. Leaves often rather wide == Neuwiedia
1b. Stamens 2; anthers fused to each-other with one or both margins, clasping the style; staminode absent or when present fused along the upper style portion. Inflorescences usually branched, recurved or spreading, not erect. Ovary and fruit narrowly cylindrical, not strongly contracted at the apex. Leaves usually narrow == Apostasia


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Family Orchidaceae Subfamily Apostasioideae

Neuwiedia veratrifolia Blume, flower, photo A. Kocyan, from Borneo, Sabah

Family Orchidaceae Subfamily Apostasioideae

Apostasia wallichii R.Br., photo A. Kocyan, from Sabah, Borneo