Invasive Alien Species

Species Name: Polytrias amaura

Family Name:
Poaceae/Gramineae
Synonym:
Polytrias praemorsa (Nees) Hack
Andropogon amaurus Buese
Eulalia amaura (Buese) Ohwi
E. praemorsa (Nees) Stapf ex Ridl.
Origin:
India
Description:
Perennial, forming dense mats, often stoloniferous, 10-40 cm tall. Stem erect, with reclining or creeping base. Leaf sheaths 2-3 cm long, tight, purplish; ligule very short membranous; blade flat, narrow, ovate-lanceolate, 1.5-7 cm x 1-7 mm. Inflorescence terminal, spike-like raceme, densely brown; spikelet in whorls of 3 at each node, 2 sessile and one stalked; both sessile spikelet dropping together with the internodes, the stalk one separately; sessile spikelet  oblong 3.5-4.5 mm long, pedicelled spikelet silimar to the sessile one but often slightly smaller and sometimes male instead of bisexual. Caryopsis oblong to obovate 1.5-1.75 mm long.
Invaded Habitat:
Grassy sites, road sides, lawns, upland rice fields.
Distribution:
Throughout Indonesia except Mollucas as far as known.
Ecology:
Sunny to lightly shaded, dry, on light or heavy, usually infertile soils; ofteh so abundant that the area has brown red during flowering. Up to 1600 m altitude.
References:
  1. Backer , C. A. & R. C. Bakhuizen Van Den Brink.  1965.  Flora of Java Vol.  III.  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.