Setaria pumila

Setaria pumila
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
(unranked):	Commelinids
Order:	Poales
Family:	Poaceae
Genus:	Setaria
Species:	S. pumila
Binomial name
Setaria pumila (Poir.) Roem. & Schult.
Synonyms
Oplismenus helvolus (L.f.) P.Beauv. Panicum flavescens Moench nom. illeg. Panicum helvolum L.f. Panicum holcoides J.Jacq. nom. illeg. Panicum luteum Gueldenst. nom. inval. Panicum pallidifuscum Schumach. Panicum pumilum Poir. Panicum rubiginosum Steud. Pennisetum helvolum (L.f.) R.Br. Setaria auricoma Link ex A.Braun Setaria boninensis Nakai nom. inval. Setaria breviglumis St.-Lag. Setaria dasyura Schlecht. Setaria erythraeae Mattei Setaria helvola (L.f.) Roem. & Schult. Setaria laeta de Wit Setaria pallide-fusca (Schumach.) Stapf & C.E. Hubb. Setaria pallidifusca (Schumach.) Stapf & C.E.Hubb. Setaria rubiginosa (Steud.) Miq. Setaria sciuroidea C.Muell. Setaria ustilata de Wit

Setaria pumila is a species of grass known by many common names, including yellow foxtail,yellow bristle-grass,pigeon grass, and cattail grass. It is native to Europe, but it is known throughout the world as a common weed. It grows in lawns, sidewalks, roadsides, cultivated fields, and many other places. This annual grass grows 20 centimeters to well over a meter in height, its mostly hairless stems ranging from green to purple-tinged in color. The leaf blades are hairless on the upper surfaces, twisting, and up to 30 centimeters long. The inflorescence is a stiff, cylindrical bundle of spikelets 2 to 15 centimeters long with short, blunt bristles. The panicle may appear yellow or yellow-tinged.

In New Zealand S. pumila can cover 20-40% of otherwise productive dairy farming pasture causing a loss in milk production.

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Wikipedia