Articles

Ludwigia octovalvis

Ludwigia octovalvis

Family

Onagraceae

Synonyms

Jussiaea suffruticosa L., Jussiaea pubescens L., Jussiaea angustifolia Lamk.

Vernacular Names

Malaysia Buyang samalam, lakom ayer, pujang malam (Peninsular).
Indonesia Cacabean (Sundanese), salah nyowo (Javanese), lakum air (Malay).
Philippines Tayilakton (Tagalog), talangkau (Iloko), pachar pachar (Sulu).
Thailand Thian nam (Peninsular), yaa raknaa (Northern).
Vietnam Mu[uw][ow]ng d[aas]t.

Geographical Distributions

Pantropical, between 320 North and 300 South.

Description

It is a perennial, robust, much branched herb and sometimes woody at the base and grows up to a height of 2(-4) m . At the lower part of stem sometimes with aerenchyme, pseudo-aerophores present in inundated conditions normally with appressed or spreading hairs.

The leaves are narrowly lance-shaped to narrowly egg-shaped with a  size of 2-14 cm x 0.5-4 cm. The base is narrowly wedge-shaped. The apex is attenuate while the veins have between 11-20 pairs. The old leaves are reddish with the petiole up to 1 cm long. It has four 6-15 mm long sepals that are egg-shaped or lance-shaped.

The petals are broadly obovate or wedge-shaped and slightly notched at the extremity. The size of these yellow petals is 17 mm x 2-17 mm. There are eight stamens. The filaments are 1-4 mm long with the pollen  in tetrads. The style is 1.5-3.5 mm long.

Its capsule is 1.7-4.5 cm x 0.2-0.8 cm, terete, thin-walled, pale brown, 8 darker ribs, irregularly splitting, pedicel up to 10 mm long.

Seeds are pluriseriate in each cell, free, rounded and raphe as long as the seed.

Ecology / Cultivation

L. octovalvis occurs in humid localities, damp grasslands, rice fields, along ditches, in swamps, pools, river beds, on floating islands in lakes and in coconut plantations, from sea-level up to 1500 m altitude. Two subspecies are distinguished, subsp. octovalvis and subsp. sessiliflora (Micheli) P.R. Raven.

Line Drawing / Photograph

BOT00011

References

  1. Plant Resources of South-East Asia No 12(2). 1998, Unesco.