Crossopteryx febrifuga (G. Don.) Benth.

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.

C. febrifuga is hermaphroditic.

Soils Prefers rocky soils.

C. febrifuga is a component of deciduous woodland and wooded grassland. Also found in Brachystegia woodland, often on stony hillsides. Tolerates fires.

Shade or shelter: C. febrifuga provides adequate shade. Reclamation: 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. 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.

Fodder: Bushbuck browse the leaves and shoots. Fuel: 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. 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. Medicine: The bark is used in African traditional medicine for the treatment of dysentery, diarrhoea and fevers. Other products: Leaf extracts yielded the flavonoids quercetin-3-arabinoside, quercetin-3-galactoside, quercetin-3-glucoside, myricetin-3-galactoside, quercetin-3-rutinoside, vitexin, isovitexin, two compounds tentatively identified as the xylosides of vitexin and isovitexin, orientin and isoorientin. Two bisdesmosidic saponins were also isolated from the roots. A triterpene saponin, with a ursadienedioic acid aglycone part, was isolated from the root bark and its structure was determined.