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