Invasive Alien Species

Species Name: Ludwigia peruviana

Family Name:
Onagraceae
Synonym:
Jussiaea hirta (L.) Sw.
Jussiaea  peruviana L.
Jussiaea speciosa Ridley
Origin:
Tropical America
Description:
Erect perennial robust herb, 100-200 cm tall. On inundated soil often forming numerous pseudo-aerophores arising from horizontal roots running just below the mud surface and are pressed upward by the water pressure, while the end flat horizontally. Stems apices sharply angular, densely patent-hairy. Leaves shortly petioled, scattered, entire, oblong- lanceolate, 5-15 x 1.5-4 cm. Inflorescence solitary, axillary, actinomorphic, 4 (5)- merous; Pedicel 7-25 mm long; sepal 4, petal 4, yellow; stamen 8, filaments short, anthers 2-celled, 5-6 mm long; ovary inferior, 4-5 celled; style short, thick, stigma conical club-shaped. Fruit capsule, ob-conical, sharply angular, hairy, 22-27 mm long.  
Invaded Habitat:
Along rivers and watercourses, on soggy sites, lebak rice fields. Sometimes abundant.
Distribution:
Pantropical. Introduce into Java a long time ago and has now spead throughout Java and Sumatra.
Ecology:
Found at altitude sea level up to 1400 m.
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. 
  3. Voogd, C.N.A. de. 1950. Tanaman Apakah Ini Gerangan. Buku kecil untuk taman berkelana. N.V. Uitgeverij W. van Hoeve, Bandung’s Gravenhage (translated by Soetan Sanif)