Description

Key Characters:

Growth Form: Scandent vines.

Stems: Stems densely hirsute (hairs spreading to somewhat retrorsely appressed).

Roots:

Leaves: Leaves simple. Opposite. Blades ovate to elliptic–ovate, (8–)15–24 cm long, (4.5–)6.5–11 cm wide. Apex acuminate. Base rounded to truncate or subcordate. Upper surfaces conspicuously and moderately to densely strigose; lower surfaces similar but hairs usually spreading. Margins serrate to serrulate. Petioles 2.5–7.5 cm long, densely hirsute. Stipules absent.

Flowers: Flowers 10–20 per verticillaster, in congested, unbranched, terminal, racemose inflorescences ca. 8–30 cm long, occasionally stem resuming vegetative growth after flowering, pedicels 6–13 mm long, densely shaggy hirsute, bracts ovate, usually 40–90 mm long, lowermost pair usually as large as leaves. Calyx often slightly asymmetrical, 12–20 mm long, enlarging in fruit, shaggy hirsute, lobes foliaceous, ovate, 5–10 mm long, less densely hirsute than tube, margins ± irregularly serrate or dentate, apex acute, splitting longitudinally, usually persistent or sometimes only ventral 1/2 persistent. Corolla bilabiate, white, tube tinged pink, 8–15 mm long, narrowly funnelform, sparsely to moderately hirsute, upper lip ca. 6–8 mm long, entire or 2-lobed, flat or concave, lower lip ca. 10–15 mm long, 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; ovules 1 per ovary lobe, placentation basal-axile; style 1, included, arising between lobes, shortly 2-lobed, the lobes clavate; stigmatic only at apex, 1 lobe often rudimentary; stigmas 2.

Fruit: Nutlets ca. 4 mm long; 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: Occurring along streambeds and in shaded sites in wet forest.

Elevation Range: 365–1,325 m.