4. ORCHIDACEAE subfam. VANILLOIDEAE
香荚兰亚科 xiang jia lan ya ke
Authors: Xinqi Chen, Phillip J. Cribb & Stephan W. Gale
Small to large terrestrial autotrophic or holomycotrophic, monopodial or sympodial herbs or scrambling or climbing vines. Roots elongate, fleshy; rhizome short to elongate. Stems erect or scrambling, unbranched or branched, very short to long, leafy. Leaves 1 to many, sometimes reduced to scales, alternate, fleshy or leathery, conduplicate, spreading or suberect, ovate, elliptic, lanceolate, ligulate, or oblong, green, glabrous. Inflorescences terminal or lateral, 1- to many flowered, racemose or paniculate, rarely 1-flowered; rachis sometimes pubescent; bracts conduplicate. Flowers often showy; pedicel short; ovary 1-locular or 3-locular, glabrous or pubescent; abscission layer between pedicel and ovary, sometimes with a distinct calyculus present. Sepals free, subsimilar, glabrous or externally pubescent. Petals free, glabrous; lip free or with side margins fused to column, 3-lobed or entire, usually with a callus of hairs, papillae, or backward-facing scales, lacking a nectary. Column elongate, slender, porrect, hooded at tip; anther 1, terminal, mobile; pollinia obscure; pollen loose, shed in monads or rarely tetrads; stigma 3-lobed, concave, viscid. Capsule erect to pendulous, 3-ribbed, cylindric to almost ellipsoidal, glabrous to pubescent. Seeds spherical with a hard testa.
Twenty-four genera and ca. 185 species: widespread in the tropical regions of Africa, America, and Asia, with a few species reaching temperate areas; six genera and 19 species (five endemic) in China.
Of the six genera in China, four are vines (Cyrtosia, Erythrorchis, Galeola, and Vanilla) and the other two are terrestrial herbs (Lecanorchis and Pogonia).
Key to genera
Key 3: Subfams. Orchidoideae, some Vanilloideae, primitive Epidendroideae