Brachystegia Benth.

Legumes of the World. Edited by G. Lewis, B. Schrire, B. MacKinder & M. Lock. Royal Botanic Gardens, Kew. (2005)

Vernacular

msasa, meblo, naga, ariella, bomanga, mtundu, okwen

Habit

Trees and shrubs (rarely suffrutices)

Ecology

Lowland tropical rain forest and seasonally dry forest, woodland, wooded grassland and bushland, often along rivers, margins of wetlands and on upland plateaus; a number of species form monodominant stands

Distribution

Africa (centred in Zambezian woodland [18 spp.]; Guinea-Congolian forest [6 spp. in WC and 1 sp. in W Africa] and 1 sp. in Zanzibar-Inhambane E Mozambique)

Note

Twenty three putative hybrids have been published among the Zambezian domain taxa, illustrating the problems traditionally encountered with delimiting species in Brachystegia (Hoyle in Brenan, 1967: 157-196). However, morphometric analyses by Chikuni (1998) revealed that there was little evidence of the phenotypic intermediacy distinguishing hybrids; rather the difficulty with species limits was due to inadequately defined states of highly variable characters; see taxonomic notes under Julbernardia

Leguminosae, R.K. Brummitt, A.C. Chikuni, J.M. Lock & R.M. Polhill. Flora Zambesiaca 3:2. 2007

Morphology General Habit

Trees, shrubs or suffrutices producing annual shoots from a woody rootstock, 0.25–45 m tall, sometimes low-branching; trunk sometimes buttressed to 1.5 m high; bark deeply to shallowly fissured longitudinally and coarsely reticulate, or smooth, flaking in irregular to rectangular, thick or thin scales.

Morphology Leaves

Leaves paripinnate, 15–350 mm long; petioles 2–70 mm long including a 2–8 mm long pulvinus; rachis deeply or shallowly canaliculate above; leaflets in 2–72 pairs, sessile or with petiolules 3–7 mm long.

Morphology Leaves Stipules

Stipules intrapetiolar, free, shortly connate at base or partially to fully fused; persistent to early-caducous; lamina 2–45 × 0.2–10 mm; auricles 1–35 × 0.5–15 mm if present, lateral or basal, persistent or caducous independently of the stipules.

Morphology General Buds

Axillary dormant buds ovoid to globose or much flattened.

Morphology Reproductive morphology Inflorescences

Inflorescences of terminal and/or axillary panicles or racemes up to 150 mm long; bracts 2–6 × 1–5 mm. Flowers 3–15 × 2–10 mm; bracteoles 4–20 × 2–12 mm; perianth comprising greatly reduced sepals and rudimentary petals, or petals lacking altogether.

Morphology Reproductive morphology Flowers Hypanthium

Hypanthium present, shortly cupular or cylindrical at the base, turbinate above, up to 1.5 mm from base to point of insertion of sepals.

Morphology Reproductive morphology Flowers Calyx

Sepals 0–8, 1–8 × 0.5–3 mm, imbricate, valvate or widely spaced.

Morphology Reproductive morphology Flowers Corolla

Petals rudimentary, 0–6, 0.3–7 × 0.2–1.5, filiform.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 10–18(20), connate at base for 0.5–7 mm, clearly exserted above the bracteoles, anthers dorsifixed.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary 2–10 × 1.5–3 mm, stipitate, stipe 1.5–5 mm long.

Morphology Reproductive morphology Fruits

Pods 45–300 × 15–80 mm, oblong to obovate, ventral flanges suberect, spreading, revolute or absent, epicarp smooth, endocarp dull to reddish brown, spongy around the seeds.

Morphology Reproductive morphology Seeds

Seeds up to 11 per pod, 12–30 × 10–25 mm, much flattened.