白脉芋兰 bai mai yu lan

Bolborchis crociformis Zollinger & Moritzi, Syst. Verz. 89. 1846; Nervilia crispata (Blume) Schlechter ex K. Schumann & Lauterbach; N. monantha Blatter & McCann; N. prainiana (King & Pantling) Seidenfaden; Pogonia crispata Blume; P. prainiana King & Pantling.

Tuber whitish, subglobose to ovoid, ca. 12 mm in diam. Leaf abaxially pale green, adaxially green with fine white reticulate venation, cordate or polygonal, 2.5-4 × 2.5-5 cm, slightly fleshy, adaxially sparsely setulose throughout, with 7 main veins, base cordate, margin undulate, apex acute; petiole-like stalk erect, 2-5 cm. Inflorescence 3-6 cm, 1-flowered; peduncle green, with 3 or 4 tubular sheaths; floral bract ovate-lanceolate, small, apex acute. Flower erect, not resupinate, opening widely, 18-25 mm in diam. Sepals green, lanceolate, 13-14 × ca. 2 mm, apex acute or acuminate. Petals green, narrowly lanceolate, ca. 11 × 1.5 mm, apex acute to acuminate; lip strongly reflexed above middle, white tinged pale green at base and sometimes with a yellowish patch at center, rhombic, ca. 13 × 8 mm, spurless, simple or 3-lobed, lateral margins erect and loosely enclosing column, apical margin irregularly lacerate or fimbriate; lateral lobes (when present) suborbicular, small; disk papillose, with 3 longitudinal ridges extending from near base almost to apex. Column ca. 6.5 mm, apex dilated; stigma suborbicular. Fl. May-Jun.

Grasslands; 200-300 m. S Taiwan [India, Indonesia, Malaysia, Nepal, New Guinea, Philippines, Thailand, Vietnam; Africa, Australia].

Broadly circumscribed here following Pettersson (Orchid Monogr. 5: 44-47. 1991), Nervilia crociformis is a widespread species with a variable lip shape.