Calamus oligostachys T.Evans et al.

Slender, clustering rattan. Stem climbing to 7 m or more long, often flowering when less than 2 m long, without sheaths to 0.5 cm diam., with sheaths 0.5–1 cm diam.; internodes 10–15 cm long. Leaf ecirrate; sheath green, sparsely armed with yellow-brown, horizontal or slightly ascending spines, 0.2–0.7 cm long with very slightly swollen bases; ocrea very small, unarmed, marcescent; knee present; flagellum to 2 m long; petiole of upper leaves 5 cm, channelled adaxially, rounded abaxially, unarmed or armed with a few spines abaxially, rachis to 60 cm long, adaxially unarmed, abaxially rounded, sparsely armed with hooked, black-tipped spines to 0.5 cm long; leaflets 5–9 on each side of the rachis, mostly swept forward, strongly grouped in ± opposite pairs, lowest group with a single leaflet each side, terminal leaflets in a group of four, the distal pair connate along 20–40% of their length, lanceolate, up to 14–25 x 1.8–3.4 cm, no bristles on ad- or abaxial faces, leaflet margins naked or with very occasional stiff bristles, including 1–2 close to the tip, transverse veinlets many. Inflorescence very slender, flagelliform, 1.3–2.2 m excluding terminal flagellum, very weakly branched, the male barely branched to 2 orders, the basal partial inflorescences up to 11 cm long including a stalk to 1.5 cm, with one terminal rachilla 3.5–4.5 cm long and 1–3 side branches, distal partial inflorescences unbranched; primary branches strongly swollen at base; rachillae slender; female inflorescence branched to 1 order, the partial inflorescence formed by a single rachilla arising directly from the axis, less than 10 cm total length including a stalk up to 1.5 cm and swollen at the base. Immature fruit spherical, abruptly beaked, and covered in 16 vertical rows of unchannelled yellow scales with red-brown margins. Mature seed not recorded.