Calamus bonianus Beccari; C. cambojensis Beccari; C. tetradactylus var. bonianus (Beccari) Conrard; Palmijuncus tetradactylus (Hance) Kuntze.

Stems clustered, climbing, to 6 m, to 1.8 cm in diam. Leaf sheaths green, without hairs, with scattered, yellowish brown, triangular spines to 1.5 cm, or spines absent; ocreas prominent, not spiny; knees present; flagella to 1 m; petiole short or absent; rachis to 0.5 m with to 10 clustered, lanceolate pinnae per side, apical few close together in a fan shape, apical pair joined at their bases, margins often with a thin, brown line of hairs; middle pinnae 11-28 cm, 2-6.5 cm wide at mid-point, margins bristly; cirri absent. Inflorescences to 1.8 m, usually flagellate; inflorescence bracts tubular, briefly split at apex. Fruits yellowish, globose, to 0.9 cm in diam., stalked.

Lowland rain forests or scrub forests, or sometimes around villages; below 1000 m. Fujian, Guangdong, Guangxi, Hainan [Cambodia, Laos, Thailand, Vietnam].