Growth Form: An erect to spreading, low-branching, compact, free-flowering subshrub with finely-textured leaves.
Foliage: Leaves simple, subsessile (with slight stalks), opposite, pinnately-veined, oblong, sometimes elliptic, glossy, medium to dark green, 10 to 30 mm long, 1.5 to 4 mm wide, with pubescent (covered with hair) undersides.
Stems: Multi-branched, puberulent (covered with soft, fine hairs) and reddish strigose (appressed stiff hairs).
Flowers: Flowers solitary in the axils of new leaves, trumpet-shaped, pedicels 2 to 7 mm long; petals 6, purple, 3 to 3.5 mm long; sepals crinkled, rarely absent; calyx 5 to 8 mm long; floral tube pale green, sometimes turning purplish toward apex, glabrous or slightly pubescent.
Fruits: Fruit capsules dehiscent, leathery or berrylike, oblong-ovoid, 1-celled, up to 3.5 mm long, containing numerous seeds; seeds reddish brown, suborbicular, 1 to 1.5mm in diameter, pitted.
Tolerates many soil types but requires ample moisture to become established in full sun or semi-shade. Prefers well-drained fertile soils with frequent light fertilizations. When plant becomes scraggly, tips can be pinched to incorporate vigour and to attain lush growth and more blooms. Easily propagated by softwood cuttings. Obtaining new plants from seed is difficult due to very poor germination rate. Plant also reproduces by layering, whereby the horizontal branches touch the ground and set roots.
https://florafaunaweb.nparks.gov.sg/Special-Pages/plant-detail.aspx?id=1896