Trigonostemon villosus Hook.f.,
Fl. Brit. Ind. 5 (1887)
Latin for 'soft long hairy'.
Trigonostemon merrillianus Airy Shaw
Shrub up to 8 m tall and 10 cm dbh. Stipules small. Leaves alternate,
simple, penni-veined, glabrous to hairy below, margin slightly toothed. Flowers
ca. 15 mm diameter, pink-purple, on long stalks, placed in racemes. Fruits ca.
11 mm diameter, green-reddish-black, on long stalks, 3-lobed, dehiscent
In undisturbed mixed dipterocarp and keranga forests up to 300 m altitude.
Often on hillsides and ridges, but also along rivers. On clay soils. In
secondary forests usually present as a pre-disturbance remnant tree.
Peninsular Malaysia, Sumatra, Borneo (Sarawak, Brunei, Sabah,
Local names in Borneo
Borneo: Butang-butang, Kayu surolean.