Korthalsia rostrata (Korthalsia rostrata)

Description

Slender clustering high-climbing and branching rattan, to 20 m or more. Stems without sheaths 6-9 mm diam., with sheaths 8-15 mm diam., internodes to 10 cm. Sheaths dull green with scattered short black-tipped spines to 2 mm; ocrea rarely exceeding 3 × 2 cm, inflated armed, with very short scattered spines to 3 mm; ants abundant. Leaf to 1.1 m including the cirrus to 60 cm; petiole short to well-developed, 3-15 cm; leaflets 3-7 on each side of the rachis, generally broad rhomboid, to 20 × 10 cm borne on short stalks to 3 mm, rarely (see below) narrow lanceolate, to 22 × 2 cm, upper leaflet surface dark green, lower surface whitish. Inflorescences borne on up to 4 topmost nodes, to 50 cm, bearing up to 10 rachillae; rachillae slender c. 8 × 0.7 cm, densely brown tomentose. Fruit to 2 × 1.2 cm, somewhat obovoid, covered in 15-18 vertical rows of orangey-brown scales. Seed c. 1.5 × 0.8 cm; endosperm deeply ruminate. Seedling leaf bifid. (J. Dransfield, The Rattans of Brunei Darussalam. 1997)/Palmweb. Editing by edric. Slender clustering rattan. Stems high-climbing and branching, to 20 m or more long, without sheaths 0.6–0.9 cm diam., with sheaths 0.8–1.5 cm diam., internodes to 10 cm. Leaf cirrate; sheaths dull green with scattered short black-tipped spines to 0.2 cm; ocrea not exceeding 3 x 2 cm, inflated armed, with very short scattered spines to 3 mm; ants abundant. Leaf to 1.1 m including the cirrus to 60 cm; petiole short to well-developed, 3–15 cm; leaflets 3–7 on each side of the rachis, generally broad rhomboid, to 20 x 10 cm borne on short stalks to 3 mm, rarely (see below) narrow lanceolate, to 22 x 2 cm, upper leaflet surface dark green, lower surface whitish. Inflorescences borne on up to 4 topmost nodes, to 50 cm, bearing up to 10 rachillae; rachillae slender c. 8 x 0.7 cm, densely brown tomentose. Fruit to 2 x 1.2 cm, somewhat obovoid, covered in 15–18 vertical rows of orangey-brown scales. Seed c. 1.5 x 0.8 cm; endosperm deeply ruminate. Seedling leaf bifid, with praemorse tips. (Palms of Thailand).In Sabah it is partially replaced by K. furtadoana, which differs in the usually few, thick rachillae with conspicuous bracts and the conspicuous fine close transverse veinlets in the leaf. Both species are recorded for Brunei, and there may occasionally be problems in identifying sterile material. In Temburong District and in parts of neighbouring Sarawak, K. rostrata occurs as a distinctive form with lanceolate rather than rhomboid leaflets. There are only a few collections. Although the leaflet shape seems so distinctive, it is otherwise identical to K. rostrata.