大花线柱兰 da hua xian zhu lan

Plants 12-25 cm tall, slender. Rhizome elongate. Stem erect, 3-6-leaved. Leaves cauline, withered and pendulous at anthesis, green, often tinged with red, lanceolate, narrowly elliptic, or ovate, 2-5 × 1-2 cm, apex acute; petiole-like base 1.5-2.5 cm including tubular sheath. Inflorescence 6-20 cm, with 2 or 3 sterile bracts, pubescent; sterile bracts small, abaxially pubescent; rachis 2-10 cm, laxly to subdensely 4-23-flowered; floral bracts lanceolate, ca. 10 mm, slightly shorter than ovary, abaxially pubescent, apex long acuminate. Flowers resupinate, relatively large; ovary and pedicel narrowly elliptic, 7-10 mm, pubescent. Sepals greenish, ovate, 5-7.5 × ca. 3 mm, pubescent; dorsal sepal tinged white toward apex, 1-veined, apex obtuse; lateral sepals slightly longer than dorsal sepal, 1-veined, margin white, apex obtuse to acute. Petals white, oblong, slightly oblique, 5-7.5 × 2-3 mm, glabrous, 2-veined, apex obtuse-subtruncate; lip white, sometimes with a yellow patch on disk, Y-shaped, 7-9 mm, 3-partite; hypochile concave-saccate, ca. 2 × 1.5 mm, containing 2 lamellate calli, each often with a linear extension; mesochile ca. 2 mm, narrow, margin erect; epichile dilated, distinctly 2-lobed; lobes not diverging widely, orbicular to obovate, 3-5.5 × 3-4 mm, apical margin undulate. Column ca. 3 mm; wings lacking; rostellum arms ca. 1 mm. Fl. Feb-Apr.

Forests; ca. 600 m. Hainan, Hunan [Thailand, Vietnam].