About Pterocarpus angolensis DC.
Pterocarpus angolensis DC. is a deciduous tree that typically grows to 16 meters in height. It has dark brown bark and a tall, wide-crowned canopy made of shiny compound leaves. In preferred wetter locations, trees usually reach 18–19 meters tall. Leaves emerge when the tree flowers, or shortly after flowering. The leaves are alternate, deep green, and imparipinnate, with 11 to 19 subopposite to alternate leaflets; each leaflet measures 2.5–7 cm long and 2–4.5 cm wide. The tree produces abundant scented orange-yellow flowers in panicles 10–20 cm long, and flowering occurs in spring. In southern Africa, this typically happens just at the end of the dry season, often around mid-October. Its fruit is a pod 2–3 cm in diameter, surrounded by a circular wing 8–12 cm across. The pod looks like a brown fried egg, and contains a single seed. This brown, papery, spiky seed pod remains on the tree long after its leaves have fallen. When growing in poorly drained areas, the tree still survives but develops a more open growth habit, with leaves growing only at the ends of long branches, creating a "stag-headed" appearance. This species is commonly called a blood wood tree, because cutting it releases dark red sap that looks like bleeding. Pterocarpus angolensis is native to southern and eastern Africa, where it grows across a wide range of localities that have a distinct dry season contrasting with a wet season. It grows best in warm, frost-free conditions. It requires deep sandy soil or well-drained rocky slopes, in areas with annual rainfall above 500 mm. It grows well in open woodland, such as the Mashonaland plateau in Zimbabwe and the northern KwaZulu-Natal region of South Africa, where it develops a broad crown with thick branches, and acts as a pioneer species on woodland and forest margins. The largest, healthiest specimens grow in the seasonal closed woodland of central Mozambique and parts of Malawi, where the species sometimes forms pure stands. Many animals feed on Pterocarpus angolensis: larvae of charaxes butterflies, squirrels, baboons, and monkeys eat its seed pods, which reach around 12 cm in diameter. Elephants have been recorded destroying Pterocarpus angolensis by pushing the trees over. The wood of Pterocarpus angolensis has multiple uses. Its brown heartwood is resistant to borers and termites, is durable, and has a pleasant spicy scent. The wood polishes well, and is widely known in tropical Africa as mukwa, used to make high-quality furniture with an attractive light brownish-yellow color. It is also used to make decorative curios and tools. Because the wood has very little shrinkage or swelling when exposed to moisture, it is ideal for building canoes. Furniture and curios are often made from the reddish sapwood. The sapwood's red color comes from the plant's characteristic dark red sap, which is the source of the common name Bloodwood. The wood produces a rich, resonant sound, so it is used to make many different types of musical instruments; in Zimbabwe, the traditional mbira is traditionally carved from mukwa wood. Methanolic extracts from the bark of this tree have been reported to have molluscicidal activity against some species of freshwater snails. The resemblance of the tree's sap to human blood has led to a belief that the tree has supposed magical healing properties for blood-related conditions. For this reason, along with its natural fire resistance, Pterocarpus angolensis is sometimes planted around chief's enclosures to serve as a living fence.
