Description

Key Characters:

Growth Form: Scandent vines climbing to 1–2 m; up to 2.6–6 m in cultivation.

Stems: Stems quadrangular, glabrous.

Roots:

Leaves: Leaves simple. Opposite. Blades lanceolate, 8–12 cm long, 3–3.5 cm wide. Apex acute or weakly acuminate. Base cuneate. Surfaces mostly glabrous, antrorsely strigulose along the adaxial midvein;l blades coriaceous. Margins inconspicuously serrulate. Petioles 1–2 cm long, glabrous or occasionally with scattered hairs. Stipules absent.

Flowers: Flowers (3)5 per verticillaster, axillary, sometimes some of them on a peduncle up to 2–5 mm long, pedicel 2–5 mm long, retrorsely strigulose. Calyx nearly radially symmetrical, narrowly campanulate, 9–15 mm long at anthesis, enlarging in fruit, green or tinged purple, glabrous, the teeth linear-lanceolate, 5-8 mm long at base, splitting longitudinally, usually persistent or sometimes only ventral 1/2 persistent. Corolla bilabiate, very dark maroon, hispidulous externally, the hairs weakly antrorse, the margins and inner surfaces glandular puberulent, the tube narrowly funnelform, mostly straight, curved slightly at the throat, 11–12 mm long, upper lip 9–10 mm long, entire or 2-lobed, flat or concave, lower lip 2–3 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 1-seeded; 4 mm long; fleshy; dark purple; 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:

Elevation Range: