Shrubs or small trees. Lvs alternate, terete to broadly flattened, sometimes with spiny apex. Fls axillary, bracteate, usually few to many in clusters, occasionally in globose heads, ☿, pedicellate. Perianth tube slender, straight at first but later curving back and usually the segments becoming free; limb ± globose. Anthers sessile in the concave perianth segments. Nectaries united to form a large or small horseshoe-shaped or completely annular gland. Ovary glabrous, usually shortly stipitate; ovules 2; style usually > perianth, curved and protruding from perianth slit in immature fl.; apex dilated, forming an oblique disc or lateral cone; stigma small, in centre of dilated style. Fr. a very woody, ± ovoid capsule splitting into 2 solid valves with flat inner faces. Seeds 2, with a broad terminal wing sometimes continuing down the upper and rarely the lower margin.