Description

Key Characters:

Growth Form: Non-aromatic perennial herbs, lianas, or subshrubs.

Stems: Stems erect to decumbent, quadrangular, many-branched or occasionally only sparingly so, usually pubescent.

Roots:

Leaves: Leaves simple. Opposite. Blades elliptic, 6–10 cm long. Surfaces hirsute. Petiolate. Stipules absent.

Flowers: Flowers 6–8 per verticillaster. Calyx usually obconical or campanulate, 2.5–2.7 mm long. Corolla bilabiate, white or sometimes tinged pink or purple, rarely pink, tube narrowly funnelform, usually curved, upper lip entire or 2-lobed, flat or concave, lower lip larger, 3-lobed, lateral lobes ovate, slightly asymmetrical, lower lobe broadly ovate to suborbicular, slightly folded to form a groove, margins somewhat undulate, apex emarginate or entire; nectary disk often present at base of ovary, annular or developed on anterior side only. Stamens 4, both pairs of similar length or upper pair slightly longer, ascending the upper corolla lip, included, aligned with the sinuses; filaments inserted near throat, usually pubescent; anthers dithecal, opening by longitudinal slits; anther sacs divaricate. Ovary superior, 2-carpellate, placentation basal-axile; ovules 1 per ovary lobe; style 1, included, arising between lobes, shortly 2-lobed, the lobes clavate; stigmatic only at apex, 1 lobe often rudimentary; stigmas 2.

Fruit: Nutlets 1-seeded; dark green to black; drupaceous; exocarp fleshy; obovoid; margins slightly winged; obliquely attached at the connate base; spreading and exserted from calyx at maturity. Seeds with endosperm absent or scanty and oily.

Ploidy:

Habitat:

Elevation Range: