Description: Herb, 40-100 cm tall, glabrous or pubescent. Leaves ovate or elliptic to ovate-oblong, 7-15 × 3-8 cm, thin, glabrous to sparsely strigose on both surfaces, lateral veins 6-9 pairs; apex acuminate; base cuneate to subcordate; margin coarsely serrate, setose between; petiole 1-5 cm. Inflorescences in terminal leaf axils, racemose, 5-10 cm long, 3-8-flowered; bracts at base, persistent, ovate, ca 3 mm, apex mucronulate; peduncles 1.5-3 cm. Flowers yellow, sometimes with red-brown spots on sepals, lip and standard, 3-3.5 cm deep; pedicels 0.5-3 cm, slender. Lateral sepals 4; outer 2 orbicular or obovate, 7-10 mm, thick, apex mucronulate; inner 2 minute, ca 3 mm, rarely seen. Lip saccate, 2-2.5 cm deep, incurved, involute, hooked spur to ca 1.2 cm; mouth oblique, 1-1.5 cm. Standard (upper petal) obovate, 1.3-2 x 1-1.7 cm, broadly triangular cristate, appendage to ca 1 cm long; wing petals separate, 3-3.3 cm long; distal lobes dolabriform, ca 2.8 cm, apex obtuse, auricle at base with yellow patches; basal lobes smaller. Capsule clavate, curved, 1.5-2.5 cm. Seeds many. |
