Calamus exilis Griff.

Slender solitary or clustering rattan. Stems climbing to 15 m long, usually less, without sheaths 0.4–0.6 cm diam., with sheaths 1.5 cm (rarely to 2.5 cm) diam.; internodes to 15 cm long. Leaf ecirrate; sheaths dull grey brown, vary variable in armature, always very densely covered with minute spines giving a scabrid feel to the whole sheath, triangular spines to 1.2 cm long with hairy margins sometimes also present on the sheaths, particularly in montane populations; knee conspicuous, armed as the sheath; ocrea inconspicuous; flagellum to 1.75 m long; petiole to 15 cm long; rachis 20–40 cm long, scabrid as the leaf sheaths, bearing conspicuous pale chestnut-brown hairs adaxially among the bases of the leaflets; leaflets 20–25 on each side of the rachis, regularly arranged, linear-lanceolate to lanceolate, to 15 x 0.8 cm, rather thin in texture, densely covered with fine pale bristles on both surfaces and margins, rarely these bristles almost absent. Inflorescences flagellate, to 75 cm long, with 2–7 partial inflorescences, the male inflorescence branched to 3 orders, the female to 2 orders; rachillae of both sexes strongly reflexed, the male to 1 x 0.1 cm, the female to 4 x 0.3 cm, the flower groups with conspicuous circular cup-like attachment. Mature fruit ovoid to oblong, to 1.3 x 0.8 cm, borne on a large disk, briefly beaked, covered in 15–18 vertical rows of straw-coloured scales. Seed ovoid to oblong, c. 1 x 0.6 cm, flattened on one side, very deeply and sinuously grooved, the whole with a thin, green, intensely bitter and foetid sarcotesta; endosperm homogeneous. Seedling leaf pinnate with up to 10 ciliate hairy leaflets on each side and conspicuous rusty hairs adaxially along the rachis.