Commelina petersii Hassk.

Perennial herb, erect or scrambling, up to 0.8 m tall with long internodes; roots hard, covered by roothairs. Leaves narrowly ovate-acuminate, up to 100 x 20 mm, abruptly narrowed at base into a pseudo-petiole and a long membranous sheath, dark green above, paler below, laxly and minutely asperous. Spathe solitary, falcate, c. 25-30 mm long, acuminate, shortly fused at base, mucilaginous inside; on a peduncle 20-30 mm long. Upper cyme on a long exserted peduncle, bearing a male flower or barren. Flowers with petals blue, sometimes with a mauve tinge. Capsule oblong; ventral locules 2-seeded; seeds long-ellipsoid with deep transverse grooves and minutely tuberculate ridges.

It is a tropical plant.