Cynometra alexandri

Cynometra alexandri is an evergreen tree in the pea family, Fabaceae. Its common names include Uganda ironwood and muhimbi. It comes from tropical Africa, from west-central regions to northern Tanzania. Records include DR Congo, Uganda, Rwanda and Tanzania. It grows in rain forest, often in groups on firm ground. It also occurs in drier forests and swamp forests.

In cultivation, its listed size is about 98 feet (30 metres) tall and wide. Growth is moderate. Forest trees can reach 164 feet (50 metres). The broad crown has a flat top. The trunk is straight and round, though some trees branch low. Others lack branches for up to 85 feet (26 metres). Trunk width ranges from about 0.7 to 4.9 feet (0.2–1.5 metres). Thin buttresses spread from the base. These can extend 26 feet (8 metres) and rise several metres. The tree keeps its leaves through the year. Its flowers have a sweet scent, and bees pollinate them.

This tropical tree needs sun rather than shade. It prefers moist soil that drains well. Loam and clay suit it. It accepts mildly acid, neutral and mildly alkaline soils. Plants For A Future lists USDA zones 10–12. Growers can raise it from seed. The same source reports that it fixes nitrogen and draws wildlife. Its natural forest sites lie at elevations of 2,297–3,937 feet (700–1,200 metres).

People plant this tree for shade and to help conserve soil. Its broad crown gives it value as an amenity tree. People also harvest wild trees for timber, both locally and for trade. The heartwood is reddish brown with darker marks. The paler outer wood turns light yellow when exposed. The timber has a fine texture and grain that often interlocks. It is hard, heavy and resists wear. Uses include heavy floors, posts, railway sleepers and marine works. People also burn the wood as fuel or make charcoal.

The heartwood resists termites, but this does not establish resistance in living trees. The timber dries slowly and may crack at its ends or surface. It can blunt tools and be hard to work. No food or medicinal uses are known in the supplied sources. They report no known hazards, but do not establish safety for people or pets.