东部叉柱兰 dong bu cha zhu lan

Zeuxine tabiyahanensis Hayata, Icon. Pl. Formosan. 6: 89. 1916; Cheirostylis nemorosa Fukuyama; Macodes tabiyahanensis (Hayata) S. S. Ying; Z. nemorosa (Fukuyama) T. P. Lin.

Plants 10-20 cm tall. Rhizome creeping, terete, short; roots emerging from rhizome nodes, cylindric, slender, densely pubescent. Stem ascending, 5-8 cm, 5- or 6-leaved. Leaves cauline to clustered at stem apex, elliptic-oblong, 5-7 × ca. 2.5 cm, base cuneate, apex acute; petiole-like base and sheath 1-2 cm. Inflorescence 6-7 cm, sparsely pubescent, with 2 or 3 sterile bracts; rachis 3-4 cm, subdensely 3-8-flowered; floral bracts lanceolate, 1.5-2 × ca. 0.4 cm, abaxially pubescent, apex acuminate. Flowers slightly nodding; ovary and pedicel 7-9 mm, sparsely pubescent. Sepals free, not spreading, green, tinged with pink, outer surface pubescent, 3-veined; dorsal sepal ovate, 8-10 × ca. 5 mm; lateral sepals oblong, 8-10 × ca. 4 mm. Petals appressed to dorsal sepal, white, obovate-oblong, falcate, 8-10 × ca. 4 mm, 2-veined; lip white, 8-10 mm, 3-partite; hypochile saccate, containing 2 several-toothed, papillose, comblike calli; mesochile thickened, ca. 2 mm, canaliculate with margin first incurved but slightly recurved distally; epichile transversely dilated, 2-lobed; lobes upturned, subsquare, ca. 4 mm, margin irregularly dentate, teeth shallow with obtuse tips. Column 3-4 mm; stelidia elongate, parallel and subequal to rostellum arms; anther triangular-ovoid, ca. 2 mm; pollinia ca. 1.5 mm; rostellum arms 2-2.5 mm. Fl. Mar-May.

● Broad-leaved forests; ca. 1000 m. S Taiwan.

This taxon, the generic placement of which has been questioned by several authors, was transferred most recently to Cheirostylis (Pearce & Cribb, Edinburgh J. Bot. 56: 278. 1999) on account of the shape of the lip, despite it having cylindric roots that emerge from the rhizome nodes and sepals that are not fused into a synsepal to form a tube.