白花凤蝶兰 bai hua feng die lan

Aerides biswasiana Ghose & Mukerjee, Orchid Rev. 53: 124. 1945.

Stems erect or pendulous, terete, to 50 cm or longer, stout, 5-7 mm in diam., often unbranched, internodes 3-4 cm. Leaves well spaced, terete, 13-16 cm × 3-4 mm, fleshy, abruptly contracted at apex and aristate. Inflorescence often slightly shorter than leaves, 1-3-flowered; peduncle with 2 or 3 short sheaths; floral bracts broadly ovate-triangular, 3-4 mm, slightly fleshy. Flowers opening widely, creamy white, sometimes tinged pale pink, large, thinly textured; pedicel and ovary ca. 3 cm. Sepals similar, obovate, ca. 2 × 1 cm, obtuse-rounded, lateral sepals adnate to column foot. Petals oblanceolate, ca. 1.8 × 1.5 cm, base contracted, margin ± erose, apex rounded; lip spurred, 3-lobed; lateral lobes erect, parallel to column, bilobed; proximal lobule linear, ca. 1.7 cm, attenuate toward apex; distal lobule ca. 2 mm, apex emarginate; mid-lobe spreading, subflabellate, ca. 1.4 cm, deeply bilobed, base with a claw ca. 5 mm, with 3 fleshy keels adaxially; spur cylindric, ca. 2.5 cm × 3 mm, narrowed toward tip, slightly hooked. Column ca. 1 × 0.7 cm. Fl. Apr.

Epiphytic on tree trunks in forests; 1700-1900 m. S Yunnan [Myanmar, Thailand].

Papilionanthe uniflora (Lindley) Garay was reported to be found in SE Xizang (K. Y. Lang & Z. H. Tsi in C. Y. Wu, Fl. Xizang. 5: 778-780, fig. 421. 1987, as Aerides uniflora (Lindley) Summerhayes). The identification was based on a fruiting specimen that is very similar in habit to P. biswasiana rather than P. uniflora.