Brachystegia bussei

Brachystegia bussei Harms

Common names

Smooth bark Brachystegia (English); musonsolo, mukongolo (Bemba/Nyanja/Tumbuka); muselele, mkongolo (Kunda/Nyanja); msale, mtwana, mwanza-masaka, mzeza (Nyanja); musewa (Tumbuka).

General description and distinguishing characteristics

A tree to 20 m, Brachystegia bussei is recognised by its smooth, purple-grey bark and fresh, lime-green leaves. This species is characteristic of rocky hills, ridges and escarpments, and is often the only tall tree around, being well adapted to growth on thin soils. It generally has a rounded crown and is often found in stands, as if in a plantation. Bark: Pale grey to purple-grey, smooth like a gum tree, with circular flakes falling off to reveal rusty ochre under bark. Leaves: Alternate compound paripinnate with 2-4 widely spaced pairs of leaflets on each leaf. Leaflets ovate-lanceolate (assymetric), typically 2-4 x 4-8 cm, distal pair largest, fresh green and glabrous when mature, crimson-bronze to glaucous purple when young. Stipules lanceolate to linear, falling early. Auricles absent. Flowers: Produced in small axillary and terminal racemes, the inconspicuous regular flowers have white-ciliate tepals (diameter up to 0.7 cm). The flowers are produced at the end of the dry season/beginning of rains (October-Decmber). Fruit: A flattened rhomboid pod, green with a greyish bloom when young, becoming shiny, pale brown and woody with age. Typically 2-4 x 6-12 cm; bursting at the end of the dry season (October) the year after flowering.

Range and habitat

B. bussei is found in Zambia, Malawi, Mozambique, Tanzania and DR Congo. In the valley Brachystegia bussei thrives on thin, rocky soils, especially those of quartzites, schists and granite. It is found at altitudes ranging from 300 m to 1500 m, but is most common at the middle of this range. It is usually locally dominant and niche specific, and is therefore a good indicator of thin, basement-igneous derived soils.