Invasive Alien Species

Species Name: Amaranthus spinosus

Family Name:
Amaranthaceae
Synonym:
Origin:
It has been expected that A. spinosus originates from lowland tropical South and Central America, and that it was introduced in other warmer parts of the world from about 1700 AD onwards.
Description:
An annual, erect, monoecious herb, often much-branched, 15-100 cm tall. Stem glabrous, terete or obtusely angular, fleshy, reddish, with slender spines at the leaf axils and branches. Leaves alternate, simple, oval to oblong in outline, tip blunt with hair-like point, base narrow to a long leaf stalk; larger leaves 3.5-11 cm by 1-4.5 cm.  Inflorescences in dense spikes arising from leaf axils, flower small, greenish, flower-cluster entirely ; those of the spikes and panicles entirely or for the greater part ?‰ above the base. Fruit one-seeded dehiscent capsule; seeds shining black, 1 mm across.
Invaded Habitat:
Up land rice fields, sugar cane plantations, vegetable fields,gardens, pastures,  road sides, railway yards and waste grounds.
Distribution:
Pan-tropical, distributed throughout  Indonesia.
Ecology:
In open or light shade, not to dry places, prefers moist and rich soils. Up to 1800 m alt. Up to 20000 seeds/plant.
References:
  1. Backer , C. A. & R. C. Bakhuizen Van Den Brink.  1965.  Flora of Java. N.V. P. Noordhoff. Groningen, Netherlands. 
  2. Barnes, D.E. & L.G. Chan. 1990. Common Weeds of Malaysia and Their Control. Ancom Berhad, Persiaran Selangor. 40000 Shah Alam Malaysia.
  3. Galinato, M.I., K. Moody and C.M. Piggin. 1999. Upland rice weeds of South and Southeast Asia. IRRI.
  4. Lemmens, R.H.M.J. and N. Bunyapraphatsara. 1999. Amaranthus spinosus L. in  de Padua, L.S., N. Bunyapraphatsara and R.H.M. J. Lemmens (eds.) Plant Resources of South-east Asia No. 12(1). Prosea, Bogor, Indonesia.
  5. Miyaura, Rie.  2001.  Weed Distribution and Its Control in Highland Indonesia : The Case of West Java and Bali.  In Highland Vegetable Cultivation in Indonesia, A Multi-Disciplinary Study toward Eco-Eco Farming.  Tokyo, Japan.  
  6. Munawaroh, E. and Y. Purwanto.  1990.  Pengamatan Beberapa Aspek Biologi Amaranthus spinosus L. Prosiding 1 Konferensi HIGI X.  Malang, Indonesia.  
  7. Soerjani, M.,  A. J. G. H. Kostermans & Gembong Tjitrosoepomo (Eds.).  1987.  Weeds of Rice in Indonesia. Balai Pustaka. Jakarta