Acrotrema costatum Jack
|Malaysia||Meroyan punai tanah (Pahang, Peninsular).|
|Thailand||Pot khon, wan chai maha prap, san tao (Peninsular).|
Acrotrema costatum is distributed from southern Burma (Myanmar), peninsular Thailand, Peninsular Malaysia and northern Sumatra; possibly also in Bangka.
A. costatum is a small perennial herb with a horizontal woody rhizome.
The leaves are in a rosette or on a very short stem and then arranged spirally, simple, obovate, measuring 7-25 cm x 3-10 cm, dentate, auriculate at the base, hairy, deep green and usually with a whitish or greyish area along the midrib or marked with red. The petiole is measures 1-2(-6) cm long.
The inflorescence is a terminal erect raceme, red-hairy, bracteates and up to 12-flowered. The flowers are regular, 5-merous, bisexual, open singly and about 3 cm in diametre. The petals are yellow in colour. The stamens are numerous and in 3 bundles. The carpels are 3.
The fruit is a follicle that enclosed by the persistent sepals, irregularly dehiscent and up to 15 seeds.
The seeds are finely echinate and with a white aril.
A. costatum occurs in dense rain forest, also in secondary forest, often on moist shady rocks, up to 1000 m altitude. It is common in many localities.