Leaves : Six at a node, oblong, lanceolate, base narrow, sessile, hairy; the outer leaves of the whorl larger than others, each one with a yellow straight spine in its axil.
Flowers :
4-pairs at each node, bracts leaf-like, lanceolate, hairy, bracteoles linear-lanceolate, lower portion ciliate with long white hairs.
Calyx 4-partite, sepals upper broader, lanceolate, ciliate and hairy.
Corolla purplish-blue, bilabiate, tube swollen, lips subequal, the upper bifid, lobes oblong, the lower with 2 crest-like longitudinal folds on the palate deeply 3-lobed.
Stamens 4, didynamous, filaments unequal.
Ovary 2-celled, ovules 4 in each cell, style hairy, stigma acuminate.
Fruit : Capsule oblong, seeds 4-8, with hygroscopical white hairs.
