Begonia oxyloba Welw. ex Hook.f.

Begoniaceae, Vanessa Plana, Martin J.S. Sands & Henk J. Beentje. Flora of Tropical East Africa. 2006

Type

Type: Angola, Golungo Alto, Welwitsch 875 (BM!, lecto.; COI, G, K!, iso.).

Morphology General Habit

Erect, terrestrial herb 10–150 cm high (or scrambling up to 2 m), rarely branching; stem reddish or translucent, succulent, becoming woody with age; indumentum of simple hairs.

Morphology Leaves Stipules

Stipules elliptic to ovate, 1–3 cm long, caducous, boat-shaped, apex acuminate, with minute scattered glandular hairs.

Morphology Leaves

Leaves green above, reddish or purplish beneath, drying papery, asymmetrical, commonly 3–5lobed to almost palmatifid, sometimes transversely broadly ovate with 5 apices, 7–28 × 10–19 cm, base obliquely cordate, margin denticulate to serrulate to almost entire, if leaves not lobed then with 5 acute to caudate points (large teeth), apex of lobes acute to acuminate, if leaves not lobed then apex caudate to acuminate, sparsely puberulent to glabrous; venation palmate; petiole reddish, 8–24 cm long.

Morphology Reproductive morphology Inflorescences

Inflorescence axillary, unisexual or bisexual, a dichasial cyme with up to 31 flowers; peduncle 1–4 cm long; each ramification subtended by a pair of caducous ovate to broadly ovate acuminate bracts 0.7–1.4 cm long, chartaceous, with conspicuous veins; pedicels 0.3–2.3 cm long; bracteoles absent.

Morphology Reproductive morphology Flowers

Female flowers: tepals 2(–4), the outer and inner very similar to those in male flowers; ovary ellipsoid, wings absent, 3-locular; placentation parietal through 60% of the ovary; styles 3, forked at the apex, spirally twisted once, glabrous; stigmatic band yellowish green. Male flowers: tepals 2(–4), white to pink with darker venation, perianth cylinder absent; outer tepals broadly ovate, 0.5–1.4 × 0.4–1.6 cm; inner, if present, narrowly elliptic, less than 2 mm long; stamens 7–35, filaments free or fused only at the base, anthers narrowly obovoid, 1.5–2.5 mm long.

Morphology Reproductive morphology Fruits

Fruits greenish tinged with red, fleshy, ellipsoid or trigonous, 2–3 cm long, 0.6–1.2 cm in diameter, terete to triangular in cross section with narrow longitudinal ribs or furrows, indehiscent, styles and tepals often persistent until complete maturity.

Figures

Fig. 3, p. 16.

Ecology

Moist forest, especially near water; 600–1900 m.

Conservation

Least concern (LC); widespread .

Note

There is extensive leaf variation within this species ranging from almost entire to palmatifid. There is a regional tendency for southern specimens like those from Tanzania or Mozambique to possess leaves which are almost entire, while palmatifid or lobed leaves are found in Kenya and Uganda. However, this is a variable character in itself with most specimens intermediate.

Distribution

Range: Widespread in tropical Africa from Sierra Leone and Guinea throughout Central Africa to Mozambique and Madagascar Flora districts: U2 U4 K5 T 1 T2 T3 T6 T7

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: confident

Begoniaceae, F. K. Kupicha. Flora Zambesiaca 4. 1978

Morphology General Habit

Plants 19–55 cm. tall, annual.

Morphology Stem

Stems glabrous, ascending, unbranched, rooting at lower nodes.

Morphology Leaves

Leaves petiolate; lamina 7–14 cm. long, ± ovate in outline, with 5 lobes, cordate at the base; sinuses between lobes 1/5–1/2 × length of lamina; margins irregularly and very shallowly dentate; superior surface green, glabrous or very sparsely hispid, inferior surface dark green or red when living, becoming green when dry, glabrous; petiole 8–23 cm. long; stipules c. 20 × 8 mm., linear, membranous, entire-margined, those at apex of stem very conspicuous and sheathing the growing point, later caducous; axillary bud sometimes developing into a short conical spine.

Morphology Reproductive morphology Flowers

Flowers in axillary cymes with 2 dichasia; peduncles 15–30 mm. long; primary dichasial branches 2–8 mm. long. Male flowers: tepals 2, c. 9 mm. long, pale pink, suborbicular; filaments c. 1 mm. long. Female flowers: tepals 2, c. 7 mm. long, pale pink, sub-orbicular; styles divided to c. 1/2 their length, the branches stigmatic, almost straight; ovary c. 1 cm. long, fusiform, not winged, tapering into a narrow stipe c. 1 cm. long; placentae bipartite.

Morphology Reproductive morphology Inflorescences Bracts

Bracts like stipules but very soon caducous.

sex Male

Male flowers: tepals 2, c. 9 mm. long, pale pink, suborbicular; filaments c. 1 mm. long.

sex Female

Female flowers: tepals 2, c. 7 mm. long, pale pink, sub-orbicular; styles divided to c. 1/2 their length, the branches stigmatic, almost straight; ovary c. 1 cm. long, fusiform, not winged, tapering into a narrow stipe c. 1 cm. long; placentae bipartite.

Morphology Reproductive morphology Fruits

Fruit a berry 20–30 × 8–12 mm., ellipsoid, stipe 10–22 mm. long.