Description

Key Characters:

Growth Form: Scandent or decumbent vines up to several m long.

Stems: Stems sharply or sometimes weakly 4–angled, ridges present on angles, moderately to densely tomentose (hairs usually concentrated on stem ridges) or rarely glabrous.

Roots:

Leaves: Leaves simple. Opposite. Blades narrowly to broadly ovate, 2.2–5.1 cm long, 1.1–3.9 cm wide. Apex obtuse or occasionally acute. Base truncate to cordate. Surfaces glabrous or lower surfaces moderately to densely short–pubescent; blades membranous. Margins crenate. Petioles (4–)7–15 mm long, sparsely pubescent. Stipules absent.

Flowers: Flowers 6(–10) per verticillaster, pedicels 4–9(–14) mm long, axillary, glabrous or occasionally sparsely pubescent. Calyx bilaterally symmetrical, upper lip 3-lobed, lower lip 2-lobed, tubular or narrowly campanulate, 7-14 mm long, enlarging in fruit, glabrous or rarely pubescent at base, the teeth usually obtuse, 1-3 mm long, 2.5-4 mm wide at base, splitting longitudinally, usually persistent or sometimes only ventral 1/2 persistent. Corolla bilabiate, pink, dark magenta, or purple, rarely white with a faint purple tinge, moderately to densely tomentose distally externally glabrous within, tube narrowly funnelform, strongly falcate, 22–29 mm long, upper lip 6–11 mm long, entire or 2-lobed, flat or concave, lower lip 3–6(–7) mm long, 3-lobed, the lobes flat or margins revolute, ovate, of similar size, distal portion of corolla sparsely to densely pubescent externally, the hairs simple or multicellular, occasionally glandular pubescent within, otherwise glabrous; 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, included within corolla or well–exserted beyond upper lip; filaments inserted near throat, pubescent; anthers dithecal; anther sacs divaricate, opening by longitudinal slits. Ovary superior, 2-carpellate, each carpel longitudinally divided, placentation basal-axile; ovules 1 per ovary lobe; style 1, exserted, arising between lobes, usually cleft, diverging after anther dehiscence, shortly 2-lobed, the lobes subulate; stigmas 2.

Fruit: Nutlets 5–6 mm long; 1-seeded; drupaceous; black at maturity; margins slightly winged; obliquely attached at base; included within calyx at maturity; exocarp fleshy; obovoid. Seeds with endosperm absent or scanty and oily.

Ploidy: 2n = 64*

Habitat: Occurring in mesic to wet forest and low boggy wet forest.

Elevation Range: 750–1,550 m.