Borassus caudatus Loureiro, Fl. Cochinch. 2: 619. 1790 ["caudata"]; Arenga hookeriana (Beccari) Whitmore; Blancoa caudata (Loureiro) Kuntze; Didymosperma caudatum (Loureiro) H. Wendland & Drude; D. caudatum var. stenophyllum Beccari; D. caudatum var. tonkinense Beccari; D. hookerianum Beccari; D. tonkinense (Beccari) Beccari ex Gagnepain; Wallichia caudata (Loureiro) Martius.

Stems clustered, to 1.5 m tall, 1-2 cm in diam. Leaf petioles to 0.4 m; rachis to 0.5 m; pinnae to 10 per side of rachis, linear to rhomboid (rarely blade undivided), briefly lobed along margins and with elongate apices, without ears at bases, regularly arranged and spreading in same plane except for basal few pinnae; middle pinnae to 20 cm, to 7 cm wide at mid-point. Inflorescences to 50 cm; male rachillae 1(-3), 16-20 cm; male flowers 5-8 mm; sepals ca. 1 mm; petals 5-8 mm; stamens 13-15; female rachilla 1, to 30 cm; female flowers ca. 5 mm; sepals ca. 1 mm; petals 2-3 mm. Fruits red, ellipsoid to oblong, ca. 1.5 × 0.8 cm.

The leaves are used to weave hats.

Lowland rain forests or deciduous forests, sometimes on limestone outcrops; below 700 m. Guangxi, Hainan [Cambodia, Laos, Myanmar, Thailand, Vietnam].