Tricalysia acocantheroides K.Schum.

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

Morphology General Habit

Shrub or sometimes a small tree, 1.5–5(7) m high; young twigs puberulous; older stems with greyish or light brown bark.

Morphology Leaves

Leaf blades dimorphic, those at start of new season’s growth smaller and either the same shape or more rotund; main blades (2)3.5–7.5(10) × (1)2–3.4(4) cm, elliptic, oblong elliptic to broadly elliptic or ovate, acute or shortly and finely acuminate at the apex with a mucronulate tip up to 1.25 mm long, cuneate or rarely rounded at the base, slightly recurved at margin, subcoriaceous, glabrous on both surfaces; midrib puberulous, lightly impressed above, prominent beneath; lateral nerves in 4–6 main pairs, rather faint; tertiary nerves mostly obscure; domatia hairy; petioles 2–7 mm long, pubescent or puberulous; stipule limbs 1.5–2 mm long, puberulous with awns 3–6 mm long.

Morphology Reproductive morphology Inflorescences

Inflorescences borne in leaf axils or at leafless nodes, mostly 3–5-flowered, subsessile; bract and bracteoles cupular,pubescent, those subtending inflorescence branches bearing 2 small subulate (foliaceous fide Robbrecht) appendages and 2 short awns, those subtending flowers with 4 unequal awns.

Morphology Reproductive morphology Flowers

Flowers 5–6-merous, heterostylous, sweet-scented, sessile.

Morphology Reproductive morphology Flowers Calyx

Calyx tube glabrous, hidden by upper bracteolar cup; limb-tube 1.25–2(2.5) mm long, pubescent; lobes subulate, or subulate from a deltoid base, 0.5–1.75 mm long, sometimes rudimentary lobes present between main lobes.

Morphology Reproductive morphology Flowers Corolla

Corolla white; tube 5.5–11 mm long, glabrous at base, often pubescent towards the top outside,glabrous inside;lobes 3–5 × (1.5)2–3 mm, acuminate at apex, pubescent below on the part exposed in bud, glabrous above.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers 3–3.5 mm long, shortly apiculate, ± medifixed, either sessile with tips (i.e. ¼–½ length) exserted from corolla tube, or with filaments 0.5–1 mm and mostly (i.e. ¾ held erect) or fully (i.e. spreading) exserted from corolla throat.

Morphology Reproductive morphology Flowers Gynoecium Pistil

Style and stigma/pollen presenter arms glabrous, in flowers with included anthers, arms included and lying level with anther bases or between anthers, or in flowers with exserted anthers, at throat or exserted and lying between anthers.

Morphology Reproductive morphology Flowers Gynoecium Ovary Placenta

Placenta mostly with 2 collateral ovules; sometimes 1- or 3-ovulate.

Morphology Reproductive morphology Fruits

Fruit yellow-orange, orange or red, c. 8 mm in diameter, with 2 chambers or sometimes 1 by abortion.

Morphology Reproductive morphology Seeds

Seeds 1–2 per chamber, semi-ellipsoid; testa weakly striated.