Description

Key Characters:

Growth Form: Suberect perennial herbs.

Stems: Stems densely short–hirtellous (hairs somewhat antrorse).

Roots:

Leaves: Leaves simple. Opposite. Blades ovate to occasionally elliptic–ovate, (6–)10–24 cm long, (2.5–)3.3–7 cm wide. Apex acute to short-acuminate. Base subcordate or occasionally truncate. Upper surfaces sparsely strigillose and usually short–hirtellous along midvein, also moderately glandular–dotted; lower surfaces glandular–dotted and short–hirtellous, densely so along veins; blades flaccid. Margins evenly crenate. Petioles (2.5–)3.5–7 cm long, densely finely short–hirtellous (hairs usually slightly antrorse, rarely appressed). Stipules absent.

Flowers: Flowers (2–4)6 per verticillaster, in relatively open and delicate, compound, terminal racemose inflorescences 8–17 cm long, usually consisting of the principal axis and 2 shorter lateral branches immediately below, pedicels 1.5–2(–3) mm long, finely short–hispidulous (hairs straight, spreading to erect, and usually ca. 0.2 mm long, rarely stiff, slightly antrorse, and 0.1–0.2 mm long), bracts oblong-lanceolate to oblong–oblanceolate, 2–3 mm long, lowermost pair larger, ca. 4–5 mm long. Calyx obconical, 3–4 mm long, enlarging in fruit, short–hispidulous and densely glandular–dotted, usually 5-toothed, the teeth linear–deltate, ca. 0.7–1.7 mm long, apex acute or occasionally subobtuse, splitting longitudinally, usually persistent or sometimes only ventral 1/2 persistent. Corolla bilabiate, white, tube slender, funnelform, slightly curved, 8.5–12 mm long, short–villous and usually glandular–dotted, upper lip ca. 2–3 mm long, entire or 2-lobed, flat or concave, lower lip ca. 6–9 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. 2–3 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: 2n = 64*

Habitat: Very rare in diverse mesic forest to wet forest.

Elevation Range: 450–860 m.