ORCHIDACEAE - China

EPIDENDROIDEAE 183Stem flexuous, glabrous, with 3 or 4 sheaths toward base.Leaves 2 or 3, ovate-lanceolate to lanceolate, lowest one ellipticor ovate, 2–7 × 1–4 cm, finely papillose along margins, baseamplexicaul, apex acute. Rachis ca. 4 cm, glabrous or puberulent,laxly 1–4-flowered; floral bracts narrowly ovate, 3–4 × 2–3 mm, shorter than ovary, apex acute. Flowers not resupinate,rose-pink, lip with a yellow callus on epichile and brown wartson hypochile; pedicel and ovary ca. 10 mm, puberulent. Sepalsovate, ca. 10 × 5–5.5 mm, apex acute; lateral sepals oblique,slightly wider than dorsal sepal. Petals ovate, ca. 8.5 × 5 mm,apex shortly acuminate; lip ca. 12 mm, with a mesochile connectinghypochile and epichile; hypochile cymbiform, withbroadly triangular, rounded side lobes ca. 4 mm, with numerousbrown warts; mesochile oblong, ca. 3.5 × 2 mm, with a pair offleshy low keels; epichile suborbicular, ca. 3.5 mm, with asmall callus at base, margin undulate, apex obtuse. Column ca.7 mm. Fl. Jul–Aug. 2n = 40, 60.Coniferous (Tsuga chinensis) forests, on limestone karst; 1100–1200 m. SE Yunnan [N Vietnam].61. DIPLANDRORCHIS S. C. Chen, Acta Phytotax. Sin. 17(1): 2. 1979.双 蕊 兰 属 shuang rui lan shuChen Xinqi ( 陈 心 启 Chen Sing-chi); Phillip J. Cribb, Stephan W. GaleHerbs, small, heteromycotrophic, with stout, short rhizomes and tufted fleshy roots, without green leaves. Inflorescence erect,terminal, racemose; peduncle with several sheaths; sheaths tubular in lower half of peduncle, becoming bractlike above; rachisdensely many flowered; floral bracts membranous. Flowers erect, not resupinate, actinomorphic; pedicel rather long, slender, nottwisted; ovary ellipsoid, not twisted. Perianth composed of 3 similar sepals and 3 similar petals, without a modified lip. Columnerect, cylindric, with 2 fertile stamens at apex; stamens similar, erect, borne opposite dorsal sepal and central petal (lip) respectively;anthers 2-locular, each with an extremely short filament; pollinia 2, granular-farinaceous, without caudicle; stigma terminal, oblate;rostellum absent.● One species: China.For a detailed discussion on this genus and the allied Holopogon, see Chen and Tsi (Acta Phytotax. Sin. 25: 329–339. 1987).Two of us (Cribb and Gale) consider Diplandrorchis to be a peloric form of Neottia. Our understanding of the genetic control of organdevelopment in orchids can be used to explain how zygomorphic flowers may become “regular” (i.e., actinomorphic) and how floral organs can takeon different forms, as when the lip becomes petaloid or a staminode develops as an anther. For further discussion on the occurrence of actinomorphyin the Orchidaceae and other monocot groups with zygomorphic flowers, see Rudall and Bateman (New Phytol. 162: 25–44. 2004).1. Diplandrorchis sinica S. C. Chen, Acta Phytotax. Sin. 17(1):2. 1979.双 蕊 兰 shuang rui lanPlants 17–24 cm tall. Rhizome slightly curved, ca. 2.5 mmin diam. Inflorescence slender, ca. 2 mm in diam., with 5–7membranous sheaths; lower sheaths tubular, 2–3 cm; uppersheaths ovate-lanceolate, 1–1.5 cm; rachis 6–8 cm, densely 13–17-flowered; floral bracts lanceolate, 7–8 mm, apex acuminate.Flowers pale green or greenish white, not opening widely;pedicel 4–6 mm, papillose-pubescent; ovary ellipsoid, ca. 4 ×2.5 mm, papillose-pubescent. Sepals oblong-lanceolate, ca.3.5 × 1.5 mm, outer surfaces papillose-pubescent; lateral sepalsslightly oblique. Petals and lip similar, suboblong, slightlyshorter and narrower than sepals. Column ca. 2.5 mm includinganthers; anthers broadly ovoid-oblong, ca. 0.6 mm. Fl. Aug.● Humus-rich soils in Tilia forests, shaded places; 700–800 m. ELiaoning.62. HOLOPOGON Komarov & Nevski in Komarov, Fl. URSS 4: 750. 1935.无 喙 兰 属 wu hui lan shuChen Xinqi ( 陈 心 启 Chen Sing-chi); Phillip J. Cribb, Stephan W. GaleArchineottia S. C. Chen.Herbs, small, heteromycotrophic, with short rhizomes and tufted fleshy roots, without green leaves. Inflorescence erect, terminal,racemose, sparsely papillose-pubescent above; peduncle with several tubular sheaths; rachis several to many flowered, sparselypapillose-pubescent; floral bracts membranous. Flowers erect or spreading, resupinate or not, actinomorphic or less commonly zygomorphic;pedicel rather long. Sepals similar, outer surfaces usually sparsely hairy. Petals similar, or central one a modified lip 2-lobedat apex. Column rather long, slightly dilated at apex, with a thick ridge on dorsal surface; anther erect or suberect, attached by afilament to ridge on back of column; pollinia 2, granular-farinaceous, soft, without caudicles or viscidia; stigma terminal; rostellumabsent.Six species: China, NW India, Japan, Russia (Far East); two species (both endemic) in China.In the opinion of one of us (Chen), this genus is characterized by its very distinct column structure, in which there is a thick ridge on its dorsalsurface linked at the upper end by a filament to the suberect anther, and a terminal stigma, but no rostellum. This is a reliable and stable characterfound in all the species, including those with a modified lip very similar to that in Neottia. For a detailed discussion, see Chen and Tsi (Acta Phytotax.Sin. 25: 329–339. 1987).