香线柱兰 xiang xian zhu lan

Heterozeuxine odorata (Fukuyama) T. Hashimoto.

Plants robust, 30-50 cm tall. Rhizome elongate, ca. 5 mm in diam. Stem ascending, stout, 4-6-leaved. Leaves cauline, widely spaced or sometimes clustered, not withering at anthesis, obliquely elliptic to ovate-elliptic, 5-12 × 3-7 cm, base rounded, apex acute; petiole-like base 1.5-3.5 cm including tubular sheath. Inflorescence 20-35 cm, with 3 or 4 sterile bracts, puberulent; rachis 5-8 cm, subdensely 10-15-flowered; floral bracts ovate-lanceolate, ca. 15 × 8 mm, pubescent on abaxial surface and margin, apex acuminate. Flowers fragrant, resupinate, half opening, relatively large; ovary and pedicel subcylindric, 8-10 mm, sparsely pubescent. Sepals whitish green, glabrous to puberulent; dorsal sepal ovate, concave, 6-8 × 4-5.5 mm, apex obtuse; lateral sepals obliquely ovate, 8-9 × 4-4.5 mm, apex obtuse to acute. Petals white, obliquely ovate, 7-8 × 3-4.5 mm, apex mucronate; lip white, Y-shaped, 9-9.5 mm, 3-partite; hypochile slightly dilated, saccate, ca. 4 × 3 mm, containing 2 to several lamellate calli; mesochile flat, ca. 1.5 × 1.5 mm, with 2 longitudinal keels; epichile dilated, ca. 3 × 7 mm, 2-lobed; lobes diverging at an acute angle, subsquare to suborbicular, ca. 2.8 × 2.8 mm, margin undulate, yellowish at base. Column 4-4.5 mm; wings quadrate; anther cordate, ca. 2.5 mm; rostellum arms ca. 2 mm. Fl. Apr. 2n = 20.

Shaded humid places in forests; ca. 300 m. S Taiwan [Japan (Ryukyu Islands)].