Description

Key Characters:

Growth Form: Compact shrubs (2–)3–7.5(–10) dm tall, many branched.

Stems: stems glabrous, young stems 4–costate, older stems 2–costate with hark weakly exfoliating.

Roots:

Leaves: Leaves simple. Opposite usually closely spaced and overlapping, gradually reduced distally along the stem. Blades lanceolate to ovate, rarely linear–lanceolate, 2––6 cm long, 0.5–1.5(–2.2) cm wide. Apex long acuminate to long attenuate, often falcate. Base cuneate, rounded or rarely truncate. Blades coriaceous. Margins flat to occasionally weakly revolute. Lateral veins 2-4 on each side, strongly ascending, prominent on both surfaces, the tertiary venation prominently reticulate on both surfaces, often with reddish purple tinge. Petiolate, the petioles 0.2–0.8 cm long, glabrous, often with a reddish purple tinge. Stipules deltate, glabrous, aristate, the apex with a stiff awn 1.5–5 mm long, often with reddish purple tinge.

Flowers: Flowers in dense, 7–15- flowered, corymbiform inflorescences subtended by a pair of ovate bracts, inflorescence branches and pedicels subtended by smaller bracts. Flowers unisexual, insect-pollinated, dimorphic and the plants apparently dioecious. Calyx 4-5-lobed, lobes oblong or ovate to narrowly triangular–subulate, 2–6 x 0.5–2 mm, subequal, rigid, venose. Corolla salverform, the valvate lobes conspicuously inflexed in bud, the apex depressed in bud, the tube greenish white or rarely with pink tinge, 4-5-lobed, lobes pure white or greenish white at anthesis; nectary disc present. Staminate flowers with the corolla tube 11–14 mm long, 2–2.5 mm diam, the lobes elliptic to oblong–lanceolate, 7.5–8 × 1.5–2 mm; pistillate flowers with the corolla tube 7–8 mm long, 1.2–1.5 mm diam, the lobes 2.5–4 × 0.8–1.5 mm. Stamens as many as and alternate with the corolla lobes. Staminate flowers: stamens inserted 2-4 mm below apex of tube, the anthers 1.8-2.8 mm long, the filaments 0.2-0.5 mm long. Pistillate flowers: stamens inserted 1–3 mm below apex of tube, the anthers 0.8–1.5 mm long, the filaments 0.3–0.5 mm long. Pollen not developing in pistillate flowers. Ovary ⅔ (rarely to ½) inferior (pistillate flowers); style 6-8 mm long, 0.8-1.1 times the length of the tube, woolly-villous in lower 1/3-1/2; stigma lobes ovate-elliptic, 1- 1.5 mm long, free. Staminate flowers: ovules present at anthesis, but apparently never developing; style 5-8 mm long, 0.5-0.7 times the length of the tube, woolly-villous in lower 1/3-1/2; stigma lobes poorly developed, coherent.

Fruit: Capsules subglobose; 5––6 mm long; 5––6.5 mm diam.; dehiscing loculicidally across the disk; later weakly separating septicidally; the calyx lobes accrescent; erect; the disk raised; 1.5––2 mm long; the ovary ⅔ (rarely to ½) inferior. Seeds irregularly ellipsoid–angulate or subglobose-angulate; 0.6–0.9 mm long; seed coat dark brown or black; papillose; with well-developed oily endosperm; or endosperm occasionally scanty or absent.

Ploidy:

Habitat: Usually restricted to north- and northeast–facing cliffs and steep; narrow ridge crests and outcrops; less commonly occurring on steep rocky slopes and the upper portions of basalt cliffs. It generally occurs in windswept areas in small populations of 30 to 50 scattered plants or more in relictual lowland and montane diverse mesic forest and shrubland.

Elevation Range: