Invasive Alien Species

Species Name: Ludwigia perennis

Family Name:
Onagraceae
Synonym:
Ludwigia  gracilis Miq.
L. leucorhiza Blume
L. lythroides Blume
L. parviflora Roxb.
Origin:
Unknown
Description:
Widely branched erect annual herb, 10-75 cm tall. Stem angular, often strongly purplish, the base often with a layer of aerenchyma. Leaves scattered, narrowly elliptic to lanceolate, underneath sparingly hairy, 1.5-12.5 x 0.2-3 cm; petiole winged, 4-20 mm.  Inflorescence solitary flower or in short leavy racemes; sepals 4 rarely 5, deltoid; calyx tube sub-cylindrical, ribbed, 4-9 mm long, conspicuously red-tinged; petal 4, bright yellow, elliptic; stamen usually 4 or 5; style 0.7-1.5 mm, stigma globose. Fruit capsule thin-walledl sub-cylindrical, 4-angled; seeds ellipsoid, initially red, ultimately brown.
Invaded Habitat:
Fallow rice fields, dikes, along ditches, lowlands-irrigated and rain-fed rice fields, river and water courses, dry riverbeds, sugarcane fields
Distribution:
In Indonesia as far as known in Sumatra, Java and Sulawesi
Ecology:
Sunny, humid or marshy situations, from lowland to 500 m altitude
References:
  1. Backer , C. A. & R. C. Bakhuizen Van Den Brink.  1963.  Flora of Java. Vol. I. N.V. P. Noordhoff. Groningen, Netherlands.
  2. Soerjani, M.,  A. J. G. H. Kostermans & Gembong Tjitrosoepomo (Eds.).         1987.  Weeds of Rice in Indonesia. Balai Pustaka. Jakarta.