Calamus diepenhorstii
Clustering rattan. Stems climbing to 20 m or more, without sheaths to c. 1.5 cm diam., with sheaths to 3 cm diam., internodes to c. 15 cm long. Leaves ecirrate; sheaths dull, often brownish-green, drying brown, armed with long black flattened spines to 4 cm long, usually less, sometimes with conspicuous swollen bases, brown scales abundant between the spines; knee conspicuous; ocrea poorly developed; flagellum to 2 m long; petiole 20–40 cm long; rachis curved, to 1m long; leaflets c. 15–30 on each side of the rachis, regularly arranged, curved, linear, the longest (in one form) to 35 x 1.4 cm, or (in another form) to 50 x 2 cm, bristly on main vein on upper surface, armed with 3 rows of bristles or densely covered with bristles on the lower surface. Inflorescence to 4 m, the male and female superficially similar, the male branched to 3 orders, the female to 2 orders, with c. 5 very distant, partial inflorescences, long pendulous; male rachillae c. 50 x 2 mm; female rachillae c. 70 x 3 mm. Mature fruit rounded, c. 2.2 cm diam., briefly beaked and covered in 16–21 vertical rows of brown scales. Seed rounded 1–1.2 cm diam., deeply pitted; endosperm ruminate. Seedling leaf bifid.
The main threats to this rattan are probably cane exploitation and forest clearance.
The triangular black spines contrasting with the dull green or brown leaf sheaths are distinctive.
Global — Peninsular Malaysia, Singapore, Borneo, Sumatra (type), Philippines.
Thailand — PENINSULAR: Surat Thani, Phatthalung, Trang, Narathiwat.
Evergreen forest in the Peninsula, on hill slopes and ridge tops, to 800 m altitude.
The cane appears to be of good quality but it is not known whether it is used.