台湾隐柱兰 tai wan yin zhu lan

Cryptostylis arachnites (Blume) Blume var. taiwaniana (Masamune) S. S. Ying.

Plants 15-25 cm tall. Rhizome creeping or ascending. Leaves 1-3, pale green abaxially, green with dark green blotches adaxially, ovate to ovate-oblong, 5-15 × 3-6 cm, base obtuse or rounded, apex acute; petiole-like base with dark green or purplish brown spots, 7-12 cm. Inflorescence green with dark green or purplish brown spots, to 25 cm, glabrous, with 2-5 sterile bracts; rachis 5-15 cm, 5-15-flowered; floral bracts green with purplish brown spots, ovate-lanceolate, ca. 15 × 5 mm, 5-veined, apex acute or acuminate; ovary cylindric, 8-10 mm including pedicel, glabrous. Sepals green, lanceolate, 8-15 × 2-3 mm, 3-veined, margin involute, apex acute. Petals similar to sepals, green, 7-12 × ca. 2 mm, 1-veined, margin involute, apex acute; lip adaxially orange-purple, with scattered dark crimson spots, rhombic-oblong to obovate, 15-20 × 8-12 mm, 5-veined, lateral veins widely spaced, outermost pair running midway between midvein and lateral margins, base rounded and shallowly saccate, lateral margins slightly revolute, apex acute; disk with minute hairs. Column 2.3-2.5 mm; wings rugose; anther ellipsoid; pollinia 1-1.5 mm. Fl. Apr-Aug.

Broad-leaved forests; 100-500 m. S Taiwan [Philippines].

Sufficient material of Cryptostylis taiwaniana on which to base a critical comparison with the widespread and variable C. arachnites is presently unavailable. In particular, the stability of the primary character used to distinguish the two---namely, the presence/absence of purple-green blotches on the vegetative parts---remains uncertain. As well, other character states are similar or overlap.

"Cryptostylis philippinensis" (Schlechter, Bot. Jahrb. Syst. 58: 54. 1922) is a nomen nudum and was therefore not validly published, and neither was the intended new combination "Cryptostylis arachnites var. philippinensis" (S. S. Ying, Coloured Ill. Indig. Orchids Taiwan 1(2): 118. 1977).