Aristida is a very nearly cosmopolitan genus of plants in the grass family. Aristida is distinguished by having three awns (bristles) on each lemma of each floret. 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. Local increases in the abundance of wiregrasses is a good indicator of overgrazing, as livestock avoid them.