Calamus guruba Buch.-Ham. in Mart.

Clustering moderate-sized rattan. Stems climbing to 20 m long, without sheaths 0.5–2 cm diam., with sheaths 13–30 cm diam., internodes up to 13–30 cm long. Leaves ecirrate; leaf sheaths dull green, very densely armed with upward pointing triangular, flattened dark brown to black spines of various lengths, 0.1–2.5 cm long, the largest with decurrent bases, bases in general rather swollen and pale, the margins often irregular and with abundant caducous pale brown indumentum on and between the spines, spines around the leaf sheath mouth much larger and longer than the rest, to 15 cm long, dark brown; knee present, armed as the rest of the sheath; ocrea 10–15 cm long or more, papery, mid brown, soon disintegrating; flagellum to 0.75–3 m long; petiole 10–25 cm long, sparsely armed with dark brown reflexed spines to 0.5 cm; rachis 65–139 cm, arcuate, armed with scattered and grouped reflexed hook-like spines; leaflets 35–50 on each side of the rachis, regularly arranged, rather widely spaced, the largest 25–45 x 1.7–2.2 cm, apical pair to 5 x 0.5 cm, very briefly joined near the base, adaxially with 3 veins bristly, abaxially the main vein bristly. Inflorescences 0.3–2.5 m long, the male and female superficially similar, the male branched to 3 orders, the female to 2 orders, with a terminal flagellum, and 2–8 partial inflorescences, each subtended by a conspicuous brown flattened papery open bract, tubular at its very base, sparsely to densely armed with short pale spines to 0.4 cm long; male rachillae crowded to 1 cm x 0.2 cm, female rachillae to 10 cm x 0.3 cm. Fruit rounded, c. 0.7 cm diam., with a short beak to 1.5 x 1 mm and covered in 15–18 vertical rows of pale straw-coloured scales. Seed c. 0.5 cm diam., somewhat flattened on one side, the surface rugose; endosperm homogeneous. Seedling leaf not recorded.