Xyris capensis (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Xyris capensis Thunberg

Family: Xyridaceae

Synonyms

Xyris melanocephala Miq.

Vernacular names

• Indonesia: mendongan (Javanese), aga mancii (West Sumatra), sinar uluh uluh (Toba, Sumatra)
• Thailand: yaa hua khot (Loei).

Distribution

Widely distributed from South America, South and Central Africa to Australia. In South-East Asia found in Peninsular Malaysia, Indonesia and New Guinea.

Uses

On the Dieng plateau (Java) the peduncles are used to make coarse mats. It serves as a low-quality replacement for Fimbristylis umbellaris (Lamk) Vahl at higher altitudes where the latter does not thrive.

Observations

A perennial, grass-like herb. Leaves rigid, ensiform, 10-50 cm × 2-4 mm; sheath 6-16 cm long; ligule 2-25 mm long. Peduncle 20-96 cm × 1.5-3 mm, subcompressed, ribbed with 1 distinct wing. Inflorescence a subglobose to obovoid head, up to 1 cm in diameter; bracts with 6-9 nerves, 4-9 mm × 3-6 mm; lateral sepals boat-shaped, 6-7 mm × 1-1.5 mm; median sepal cap-shaped, 3-4 mm × 2 mm; petals yellow or yellowish, obovate, 4-5.5 mm long, claw 6-7 mm long; stamens about 2 mm long; staminodes 1.5-2.5 mm long. Fruit a 3-valved capsule, 4-6 mm × about 2 mm. X. capensis is found in swamps, on stream- and lake banks associated with sedges and Juncus species at altitudes of (600-)900-2500 m. At high altitudes the vegetative appearance of X. capensis tends to differ from the lower altitude plants with shorter, equidistant leaves.

Selected sources

47, 50, 67, 71, 160.

Authors

M. Brink, P.C.M. Jansen & C.H. Bosch