Sepal dorsal oblong-elliptic,
slightly ducted apex. Lateral sepals oblique, ovate, almost symmetrical,
acute, dorsally carinate, at slightly revolutate base. Petals ovate,
sub-rhomboid, obtuse, slightly convex.
Lip 3-lobed, glabrous. Lateral lobes oblong-ligulate,
erect, fleshy, connivent, ligulate at curved apex, in middle provided
with cushion-like callus. Midlobe oblong-ligulate or oblong-ovate,
very fleshy, glabrous, in center provided with a finely denticulate
keel running from base to tip where it merges with a compressed
callus. On each side of the median keel, one distinguishes more
or less clearly longitudinal veins. They gave their name to this
species. The disc at junction of lateral lobes is provided by 2
superimposed callus. The posterior one, completely yellow is bilobate.
The former callus, white, has two divergent appendices projected
above and on both sides of the central keel, longer than for Phalaenopsis
Short column, arcuate, fleshy, at widened
base underlined by 2 thickenings fleshy.
Pedicellate ovary sinuous from 2 to 3 cm