Tree 4–20(–27) m. high; young bark smooth, pale silver-grey, soon flaking off thinly on bole and main branches, exposing yellowish or buff-coloured patches; older bark becoming rough, darker grey or brownish, flaking in thicker scales exposing large lenticellate patches; crown usually spreading, flat-topped; upper branches divaricate; branchlets ± horizontal with delicate fern-like foliage. Young branchlets usually pubescent to tomentose, brown or rusty, soon grey with small circular lenticels. Stipules fugacious (rarely seen), free, linear to filiform, 0.5–1 cm. long, with or without a small lateral lobe at the base. Leaves with (17–)25–60(–72) closely pectinate pairs of leaflets, the middle pairs the largest; petiole 1–4 mm. long; rhachis very slender, channelled, with ± conspicuous wings and often local stipellar expansions, usually obscured by spreading, often rusty pubescence; leaflets linear to very narrowly triangular, often falcate, (3–)5–15(–20) × 1–2(–3.5) mm., acute to rounded, often minutely apiculate, obliquely truncate to subcordate at base; midrib subcentral, very slender; surfaces usually glabrous, more rarely appressed-puberulous, but usually ciliolate. Panicles terminal or terminal and axillary, 2–4 × 2–4 cm., brown-, rusty- or tawny-pubescent to -tomentose. Flowers small, greenish-white or yellowish; bracteoles 4–6 × 3–4.5 mm., puberulous to tomentose. Tepals apparently (4–)5 only, free or 2–3 partly connate, always (?) all sepaloid, broad and imbricate, up to 2 × 1.5 mm., shortly and sparsely to subdensely and (for their size) rather long-ciliate, otherwise glabrous. Stamens ± 10, usually free, 8–10 mm. long. Ovary 2.5–3 × 0.7–1 mm. Pod thinly woody, smooth, up to 12 × 3 cm. (usually much smaller), immature drying pale or mid-brown, mature blackish-purple and usually pruinose, with numerous but minute and obscure pale lenticels; sutural wings thin, spreading, each up to 4 mm. wide. Fig. 38, p. 175.
