Scrambling annual herb with long trailing stems, rooting at the nodes and short sub-erect branches. Subterranean fleshy stolons often bear reduced, self-fertilising flowers. Leaves alternate, linear-oblong, up to c. 7 cm long, often pale greyish-green, folded along the midrib, hairless or finely velvety; margin wavy. Flowers in 1-2 terminal or leaf-opposed spathes, short-lived, opening in succession. Petals blue; lateral stamens with filaments more or less winged.
Note: the subterranean or cleistogamous flowers apparently form a drought-survival development. In times of drought the above-ground parts are poorly developed while the underground stolons will thrive and produce much fertile seed. In good rainy seasons or well watered situations the reverse has been recorded. (Maheshwari & Baldev in Phytomorphology 8, p 284-285, 1958).