Tree to 10 m high, mostly dioecious; branches pendulous; short shoots not spinescent; bark thick, fissured and fibrous below, smooth in the canopy; new shoots with occasional short-arm T-shaped hairs, wider in the middle, clear. Cotyledons 2, rarely 3, narrowly elliptic, sessile, apex acute. Seedling leaves very narrowly obovate, 37–45 mm long, 5–6 mm wide, glabrescent. Adult leaves alternate, pendulous; lamina linear or narrowly elliptic, falcate, 50–90 mm long, 6–11 mm wide, glabrous, margin thick, entire, apex acuminate with a hooked mucro to 3 mm long, abaxial surface pectinate with obscured venation; petiole 5–14 mm long. Inflorescences are basitonic, terminal on short shoots, basal involucre present. Flowers small, whitish, becoming yellower with age, with floral parts in 5s regularly placed around the pistil. Sepals ovate, ± some hairs on margin, persisting. Petals cohering in the throat then recurving almost by half, salverform or recurving, c. 10 mm long, clawed, creamy yellow. Male flowers in groups of up to 4; anthers exserted at petal break, oblong, golden yellow, c. ⅓ length of filaments; filaments thick, white, tapering to apex. Pistil spindle-shaped, narrow, small, stipitate; ovary green, containing few small ovules; style elongated, approaching length of ovary. The male flowers appear to be cryptically perfect, but are mostly functionally unisexual. Female flowers solitary or paired; staminodes not exserted; anthers narrowly triangular, yellow-brown; filaments thinner, flatter, 5× length of anthers; pistil not overly stipitate; ovary plump-turgid, incompletely (tri-) bi-locular with numerous ovules; style short, stigma capitate. Fruit eventually or ‘tardily’ (Mueller 1862) loculicidally dehiscent capsule, ± globose-cordate, 8–14 mm diam., almost woody, outer yellow-orange, inner bright yellow. Seeds 4–5 mm long, angular, rugulose, red-brown, sticky.
The wood is close-grained, light in colour and very hard. Useful for wood turning and possibly engraving. Listed on several occasions as a valuable fodder plant in inland areas in times of drought (Maiden 1904, Makinson 1992, Lazarides & Hince 1993). However, Everist (1986) considers this debatable due to the acrid taste of the leaves, nevertheless it is ‘eaten by camels’ (PERTH 03213455), and ‘suspected of causing dopiness in fowls and horses’ (PERTH 03197166).