White Adder'S-Mouth Orchid

Description

Plants 3-30 cm. Pseudobulbs 4-8 mm diam. Leaves 1(-2, rarely), petiolate base sheathing stem; blade light green, ovate-elliptic, keeled abaxially, 1.5-9.5 - 1-5 cm, apex acute. Inflorescences: floral bracts lanceolate, 1.5-2 mm; pedicels 2-4.5 mm. Flowers resupinate, green or greenish white; dorsal sepal ovate-lanceolate, 1.5-2.5 - 1-1.4 mm, margins revolute, apex acuminate; lateral sepals oblong-lanceolate, slightly falcate, 1.5-2.5 - 0.5-1.2 mm, apex acuminate; petals strongly reflexed, filiform to narrowly linear-lanceolate, 1.4-2.5 - 0.3-0.4(-0.5) mm, apex rounded; lip broadly triangular, concave, 3-lobed, middle lobe ovate, apex acuminate, lateral lobes auriculate, thickened, curved upward; disc with 2 low, thickened, elongate calli, 1.3-2.2 - 1.2-1.8(-2) mm; column 0.4-0.6 - 0.4-0.6 mm. 2N = 28.