Phellocalyx vollesenii Bridson

Rubiaceae, B. Verdcourt. Flora of Tropical East Africa. 1976

Morphology General Habit

Shrub or small tree 3–7 m. tall; young branches ± square, pubescent, older branches covered with thin greyish bark somtimes flaking to reveal red-brown under-layer.

Morphology Leaves

Leaves blue-black when dry, confined to new growth at apex of stem, mature leaf-blades narrowly obovate to obovate, 9–16 cm. long, 4–7 cm. wide, apex acute to shortly acuminate, base cuneate, chartaceous, glabrous above, glabrous or glabrescent with tertiary nerves conspicuously reticulate beneath; petioles slender 0.7–1.7 cm. long; stipules ovate-triangular, 2–4 mm. long, shortly apiculate, densely covered with silky hairs inside and with a few large colleters.

Morphology Reproductive morphology Flowers

Flower-buds borne on leafing branches; flowers borne on short lateral naked branches 0.8–6 cm. long; bracts stipule-like.

Morphology Reproductive morphology Flowers Calyx

Calyx-tube 3–4 mm. long; limb 1–1.3 cm. long.

Morphology Reproductive morphology Flowers Corolla

Corolla green or yellowish green with small purple flecks outside, drying blackish; tube 1–1.4 cm. long, ± 8 mm. wide at top, sparsely pilose outside, glabrous at throat but pubescent near base inside; lobes 2–3.3 cm. long, 6–13 mm. wide, obtuse or acute, glabrous.

Morphology Reproductive morphology Flowers Gynoecium Pistil

Style creamish, 9 mm. long; stigmatic club 1.5–2.4 cm. long.

Morphology Reproductive morphology Fruits

Fruit black when mature, 4–7(–10 from field notes) cm. in diameter, 1-locular; scar fawnish, surrounded by a narrow inner and broad outer fawnish rings.

Morphology Reproductive morphology Seeds

Seeds brown, 5 mm. long, 4 mm. wide, 3 mm. thick.

Figures

Fig. 83.

Habitat

Thicket on sand or stony hill top; 270–365 m.

Distribution

T8

Rubiaceae, D.M.Bridson & B.Verdcourt. Flora Zambesiaca 5:3. 2003

Morphology General Habit

Shrub or small tree 3–7 m tall; young branches ± square in cross-section, pubescent, older branches covered with thin greyish bark sometimes flaking to reveal red-brown underlayer.

Morphology Leaves

Leaves occasionally ternate, blue-black when dry, confined to new growth at apex of branches; blades of mature leaves 9–16 × 4–7 cm, narrowly obovate to obovate, acute to shortly acuminate at the apex, cuneate at the base, membranous, glabrous on upper surface, glabrous to glabrescent with tertiary nerves conspicuously reticulate beneath; domatia present as white hairy tufts in the nerve axils; petioles 7–17 mm long, slender; stipules 2–4 mm long, ovate-triangular, shortly apiculate, densely covered with silky hairs within and with a few large colleters.

Morphology Reproductive morphology Flowers

Flower buds borne at apex of leafing branches; flowers borne on short lateral naked branches 0.8–6 cm long; bracts stipule-like.

Morphology Reproductive morphology Flowers Calyx

Calyx-tube 3–4 mm long; limb-tube 10–13 mm long.

Morphology Reproductive morphology Flowers Corolla

Corolla green, with small purple flecks outside, drying blackish; tube 10–14 mm long, c. 8 mm wide at top, sparsely pilose outside, glabrous at throat, but pubescent near base within; lobes 2–3 × 0.6–0.9 cm, oblong, obtuse to acute, glabrous.

Morphology Reproductive morphology Flowers Gynoecium Style

Style 9 mm long, creamish.

Morphology Reproductive morphology Flowers Pollen presenter

Pollen presenter 1.5–2.4 cm long.

Morphology Reproductive morphology Fruits

Fruit black when mature, 4–7(10 from field notes) cm in diameter; scar fawn- coloured surrounded by a narrow inner and a broad outer fawn-coloured ring.

Morphology Reproductive morphology Seeds

Seeds 5 × 4 × 3 mm, brown.