Invasive Alien Species

Species Name: Amaranthus gracilis

Family Name:
Amaranthaceae
Synonym:
Amaranthus polystachyus Willd.
A. viridis L.
Euxolus caudatus Moq.-Tand.
E. polystachyus Miq. 
Origin:
E. Asia
Description:
Annual, erect, ascending or rarely prostrate, often much branched, unarmed, 10-75 cm tall. Stem soft, cylindrical-obtusely angular, glabrous or sparsely hairy. Larger leaves with long petiole; blade simple, scattered, obovate to rhomboid, rarely oblong, green or suffused with purple or entire purple, often blotched with grey in the center, glabrous or sparsely hairy on the larger nerves. Inflorescence the lower one axillary, the higher ones in older plants in a terminal, continuous or interrupted spike or panicle; flowers green, monoecious, unisexual, unisexual,; bracts and bracteoles ovate, shorter than the perianth; tepals 3-4, free, persistent, subequal, green with transparent margin, in the male flowers ovat- oblong, to oblong- lanceolate, 1.5 mm long; in female ones oblong- spathulate, 0.7-1 mm, later 1.3-1.8 mm long; male flower with 3-4 stamens, filament subequal to the perianth; female flower with superior, elongate ovary, of which the tip is excerted, stylar branches 2-3, 1-5 mm long.   Seeds brown or  glossy black, 1-1.5 mm
Invaded Habitat:
Common weed in cultivated areas, waste places, gardens, along roads, rice fields
Distribution:
Throughout Indonesia
Ecology:
In the lower regions, especially below 600 m altitude, does not grows in very wet places. Prefer sandy soils or those rich in humus and fairly moist.
References:
  1. Backer , C. A. & R. C. Bakhuizen Van Den Brink.  1965.  Flora of Java Vol. I.  N.V. P. Noordhoff. Groningen, Netherlands. 
  2. Pancho, J.V. and S.R. Obien.  1983.  Manual of  Weeds of Tobacco Farms in the Philippines.  Philippine Tobacco Research and Training Center. Mariano Marcos State University.  Batac, Ilocos Norte. 
  3. Soerjani, M.,  A. J. G. H. Kostermans & Gembong Tjitrosoepomo (Eds.).  1987.  Weeds of Rice in Indonesia. Balai Pustaka. Jakarta