Description

Key Characters:

Growth Form: Apparently scandent perennial herbs.

Stems: Stems quadrangular, glabrous or sparsely pubescent in grooves.

Roots:

Leaves: Leaves simple. Opposite. Blades ovate to elliptic, 4.2–10 cm long, 1.7–3.6 cm wide. Apex acute. Base truncate to obtuse. Surfaces glabrous except pubescent on midrib; blades membranous. Margins serrate. Petioles 5–20 mm long, sparsely hirsute. Stipules absent.

Flowers: Flowers 2–6(–8) per verticillaster, pedicels 3–4 mm long, puberulent. Calyx radially symmetrical, narrowly campanulate, 8–12 mm long, enlarging in fruit, nearly glabrous, the teeth linear-lanceolate, 5–8 mm long, 1–1.5 mm wide at base, splitting longitudinally, usually persistent or sometimes only ventral 1/2 persistent. Corolla bilabiate, pubescent externally, tube apparently pale yellowish green, narrowly funnelform, nearly straight, ca. 10–16 mm long, lobes pale brown, upper lip ca. (3–)4–6(–9) mm long, entire or 2-lobed, flat or concave, lower lip ca. 2–4 mm long, 3-lobed, the lobes flat or margins revolute, ovate, of similar size, ; 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 ca. 2.5–3 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:

Habitat:

Elevation Range: