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Local names:
English (ordeal tree), Swahili (mzwale)
Crossopteryx febrifuga is a deciduous savanna tree 1.8-15 m tall, with a rounded crown and pendulous branchlets. Bark pale grey to dark brown, scaly, finely reticulate; young stems glabrous to densely hairy pubescent. Young leaves tender green. Leaf blades elliptic, elliptic-oblong, ovate, obovate or almost round, 1.5-13.5 cm long, 1.2-7.5 cm wide, rounded to shortly acuminate at the apex, broadly cuneate to rounded at the base, glabrous to densely pubescent or velvety; petioles 0.5-1.8 cm long; stipules 2-3 mm long, acuminate. Inflorescences dense and strongly fragrant, 6-10 cm long; peduncles up to 6 cm long. Calyx tube 1 mm long; lobes elliptic to linear, 0.5-1.5 mm long, obtuse or acute. Corolla creamy white or pale yellow, densely pubescent outside; tube tinged pink, 5-11 mm long; lobes round 1.5 mm long and wide. Style exserted for 3-5 mm long, 2.5-3.5 mmm wide. Fruit globose, dark purple or black, 6-10 mm across. Crossopteryx is a monospecific African genus with a wide distribution. The generic epithet is derived from Greek “krossoi” and “pteron” meaning fringed wing and is based on its seed shape. The specific epithet febrifuga relates to its medical use in fever treatment.
Ecology
C. febrifuga is a component of deciduous woodland and wooded grassland. Also found in Brachystegia woodland, often on stony hillsides. Tolerates fires.
Native range
Angola, Burkina Faso, Cote d'Ivoire, Democratic Republic of Congo, Ethiopia, Kenya, Mozambique, Senegal, South Africa, Sudan, Tanzania, Uganda, Zimbabwe
C. febrifuga is a component of deciduous woodland and wooded grassland. Also found in Brachystegia woodland, often on stony hillsides. Tolerates fires.
Poison: Betulic acid, isolated from the stem bark; showed cytotoxicity against a human colon carcinoma cell line. The bark is used by South African witchdoctors for ordeal trials.
Crossopteryx has a higher intrinsic resistance to fire (bark properties), a 20-mm diameter stem of Crossopteryx survives exposure to 650 deg C, and can withstand frequent fires.
Bushbuck browse the leaves and shoots.
The wood is used for fuel.
Timber: The wood is hard, fine textured, with a pale pink tinge and used for building domestic implements e.g utensils, tool handles. Wood also used for sculptures.
Shade or shelter: C. febrifuga provides adequate shade.
Medicine: The bark is used in African traditional medicine for the treatment of dysentery, diarrhoea and fevers.
Soil improver: The pH, available phosphorus, cation exchange capacity, total carbon content, and total nitrogen content were greater under C. febrifuga tree clumps. Potential soil respiration and mineral nitrogen accumulation was also greater beneath C. febrifuga. Soil water content was lower beneath canopies when soil moisture was greater than field capacity.