FOC_25_Epidendroidea..

Stem flexuous, glabrous, with 3 or 4 sheaths toward base.
Leaves 2 or 3, ovate-lanceolate to lanceolate, lowest one elliptic
or ovate, 2–7 × 1–4 cm, finely papillose along margins, base
amplexicaul, 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 warts
on hypochile; pedicel and ovary ca. 10 mm, puberulent. Sepals
ovate, ca. 10 × 5–5.5 mm, apex acute; lateral sepals oblique,
slightly wider than dorsal sepal. Petals ovate, ca. 8.5 × 5 mm,
EPIDENDROIDEAE
183
apex shortly acuminate; lip ca. 12 mm, with a mesochile connecting
hypochile and epichile; hypochile cymbiform, with
broadly triangular, rounded side lobes ca. 4 mm, with numerous
brown warts; mesochile oblong, ca. 3.5 × 2 mm, with a pair of
fleshy low keels; epichile suborbicular, ca. 3.5 mm, with a
small 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 shu
Chen Xinqi (陈心启 Chen Sing-chi); Phillip J. Cribb, Stephan W. Gale
Herbs, 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; rachis
densely many flowered; floral bracts membranous. Flowers erect, not resupinate, actinomorphic; pedicel rather long, slender, not
twisted; ovary ellipsoid, not twisted. Perianth composed of 3 similar sepals and 3 similar petals, without a modified lip. Column
erect, 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 organ
development in orchids can be used to explain how zygomorphic flowers may become “regular” (i.e., actinomorphic) and how floral organs can take
on different forms, as when the lip becomes petaloid or a staminode develops as an anther. For further discussion on the occurrence of actinomorphy
in 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 lan
Plants 17–24 cm tall. Rhizome slightly curved, ca. 2.5 mm
in diam. Inflorescence slender, ca. 2 mm in diam., with 5–7
membranous sheaths; lower sheaths tubular, 2–3 cm; upper
sheaths 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 sepals
slightly oblique. Petals and lip similar, suboblong, slightly
shorter and narrower than sepals. Column ca. 2.5 mm including
anthers; anthers broadly ovoid-oblong, ca. 0.6 mm. Fl. Aug.
● Humus-rich soils in Tilia forests, shaded places; 700–800 m. E
Liaoning.
62. HOLOPOGON Komarov & Nevski in Komarov, Fl. URSS 4: 750. 1935.
无喙兰属 wu hui lan shu
Chen Xinqi (陈心启 Chen Sing-chi); Phillip J. Cribb, Stephan W. Gale
Archineottia 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, sparsely
papillose-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-lobed
at apex. Column rather long, slightly dilated at apex, with a thick ridge on dorsal surface; anther erect or suberect, attached by a
filament to ridge on back of column; pollinia 2, granular-farinaceous, soft, without caudicles or viscidia; stigma terminal; rostellum
absent.
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 dorsal
surface 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 character
found 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).