Aristida

{{Short description|Genus of grasses}}

{{Automatic taxobox

|image = Aristida purpurea form.jpg

|image_caption = Purple three-awn, Aristida purpurea

|display_parents = 2

|taxon = Aristida

|authority = L.

|type_species = Aristida adscensionis

|type_species_authority = L.Lectotype designated by Henrard, Meded. Rijks.-Herb. 54: 9 (1926)[http://www.tropicos.org/Name/40019489 Tropicos, Aristida L.]

|subdivision_ranks = Species

|subdivision = See list of Aristida species

|synonyms_ref = [http://apps.kew.org/wcsp/namedetail.do?name_id=451082 Kew World Checklist of Selected Plant Families]

|synonyms =

• Kielboul Adans.
• Streptachne R.Br.
• Arthratherum P.Beauv.
• Chaetaria P.Beauv.
• Curtopogon P.Beauv.
• Cyrtopogon Spreng.
• Moulinsia Raf. 1830, illegitimate homonym not Cambess. 1829 nor Blume 1849
• Trixostis Raf.
• Aristopsis Catasús

}}

Image:Aristida stricta.jpg (A. stricta) flowers]]

Aristida is a very nearly cosmopolitan genus of plants in the grass family.[https://www.biodiversitylibrary.org/page/358101#page/94/mode/1up Linnaeus, Carl von. 1753. Species Plantarum 1: 82] in Latin[http://www.tropicos.org/Name/40019489 Tropicos, Aristida L] Aristida is distinguished by having three awns (bristles) on each lemma of each floret.{{cite web|url=http://delta-intkey.com/grass/www/aristida.htm |title=The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references |access-date=2009-08-19 |author=Watson, L. and M. J. Dallwitz. |year=2008 |work=The Grass Genera of the World }} The genus includes about 300 species found worldwide, often in arid warm regions. This genus is among those colloquially called three-awns wiregrasses, speargrasses and needlegrasses.[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=102601 Flora of China Vol. 22 Page 453 三芒草属 san mang cao shu Aristida Linnaeus, Sp. Pl. 1: 82. 1753. ][http://luirig.altervista.org/flora/taxa/floraspecie.php?genere=Aristida Altervista Flora Italiana, genere Aristida] includes photos, drawings, and range maps for several species[http://bie.ala.org.au/species/ARISTIDA Atlas of Living Australia, kerosene grasses, Aristida L.] The name Aristida is derived from the Latin "arista", meaning "awn".{{cite book |title=Gray's Manual of Botany |author= Merrit Lyndon Fernald |year= 1962 |editor= R. C. Rollins |publisher= D. Van Nostrand Company |edition= Eighth (Centennial) - Illustrated|isbn= 0-442-22250-5 |page= 174}}

They are characteristic of semiarid grassland. The Wiregrass Region of North America is named for A. stricta. Other locales where this genus is an important component of the ecosystem include the Carolina Bays, the sandhills of the Carolinas, and elsewhere, Mulga scrub in Australia, and the xeric grasslands around Lake Turkana in Africa. Local increases in the abundance of wiregrasses is a good indicator of overgrazing, as livestock avoid them.