Dipteracanthus repens (L.) Hassk.

Dipteracanthus repens (L.) Hassk.




Ruellia repens L.

Vernacular Names

Malaysia Akar keremak, deras malam, rumput halyor (Peninsular).
Indonesia Plinten, remah, sekatan (Java).
Thailand Chaa horn, faa maeng (Nakhon Ratchasima).
Vietnam qu[ar] n[oor] b[of], song d[uwj]c.

Geographical Distributions

D. repens is widely distributed in India, Burma (Myanmar), Indo-China, southern China, Taiwan, Thailand and throughout the Malaysian region except New Guinea.


D. repens is an erect or ascending herb which can grow up to 70 cm tall, with subquadrangular and finely hairy or smooth stem thickened above the nodes.

Leaves are arranged opposite, simple and entire, ovate to ovate-lance-shaped or linear-lance-shaped, 1.5-10 cm x 0.5-3 cm, rounded to acute at base, obtuse to acuminate at apex, sparingly hairy and with cystoliths. Transverse ridges connect the petioles while stipules are absent.

Flowers are solitary in the leaf-axils, bisexual, 5-merous and subsessile. The bracteoles are ovate or ovate-oblong and 1-2 cm long. Sepal is about 4 mm long, lance-shaped to narrowly triangular and subequal segments. The petal is about 2 cm long, bell-shaped with narrow base, subequally lobed with ovate-suborbicular lobes and separated by convexities, violet to white and hairy. There are 4 stamens that are inserted at the base of petal tube, didynamous but not exserted. The ovary is superior with 2-celled, subulate style and hairy with 2 unequal stigmatic lobes.

The 1-1.5 cm long fruit is club-shaped capsule with many-seeded.

Seeds are orbicular, compressed and ringed with hygroscopic hairs. 

Ecology / Cultivation

D. repens occurs in moderately shaded, often grassy localities, in roadsides, brushwood, sometimes in abandoned fields, up to 700 m altitude. It is common in many regions.

Line Drawing / Photograph



  1. Plant Resources of South-East Asia No.12(3): Medicinal and poisonous plants 3.