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-awnswiregrasses, speargrasses and needlegrasses. The name Aristida is derived from the Latin "arista", meaning "awn".
Aristida purpurea is a species of grass native to North America which is known by the common name purple three-awn.
Aristida adscensionis is a species of grass known by the common name sixweeks threeawn. It is native to the Americas but it is distributed nearly worldwide. It grows easily in disturbed and waste areas and has potential to become a weed.
Aristida californica is a species of grass known by the common names California threeawn and Mojave threeawn. It is native to the Mojave Deserts and Sonoran of northern Mexico and California and Arizona.
Aristida divaricata is a species of grass known by the common name poverty threeawn. It is native to the Americas from the central United States to Guatemala. It is a perennial grass forming clumps of unbranched stems up to 70 centimeters tall. Leaves are mostly basal and roll along the edges. The sparse inflorescence is a wide, flat, open array of spikelets that break apart easily. The grain has a twisted tip and three awns up to 2 centimeters long.
Panicum dichotomiflorum, known by the common names fall panicgrass, autumn millet, and fall panicum is a species of Poaceae "true grass". It is native to much of the eastern United States and parts of Canada, and it can be found in the Western United States through California. It may be an introduced species in some western climates. It grows in many types of habitat, including disturbed areas and chaparral habitats.
Puccinellia pumila is a species of grass known by the common names dwarf akaligrass and smooth alkali grass. It is native to North America where it grows along the coastline in the northern latitudes, from Alaska across Arctic northern Canada to Greenland. It occurs on the coast of the Pacific Northwest in the United States and it is known from the Kamchatka Peninsula. The grass is only found on the coast, in wetland habitat, beaches, and areas inundated by the highest tides, in saline sand and mud. This perennial grass grows decumbent or erect to a maximum height near 40 centimeters, often remaining much smaller, especially in harsh habitat. It may root at stem nodes which become buried in wet substrate. The inflorescence is a dense or open array of branches bearing spikelets.
Puccinellia simplex is a species of grass known by the common names California alkaligrass and western alkali grass. It is native to California, where it grows in mineral springs and other moist habitat with saline soils in the Central Valley, Mojave Desert, and other areas. It is also known from Utah, but occurrences there are probably introduced. This annual grass grows up to about 25 centimeters tall. The inflorescence is generally a linear structure with parallel branches bearing small spikelets.
Schismus arabicus is a species of grass known by the common name Arabian schismus. It is native to northern Africa, temperate Asia, and it is also known as an introduced species in the southwestern United States. It grows in many types of habitat, including disturbed areas. It is an annual grass with stems growing up to 16 centimeters long and lined with threadlike leaves. The short inflorescence bears spikelets under a centimeter long.
Schismus barbatus is a species of grass known as common Mediterranean grass and kelch-grass. It is native to Eurasia, and it is also known as an introduced species in the southwestern United States. It grows in many habitats, including disturbed areas. It is an annual grass growing in small clumps. The stems grow up to 27 centimeters long and are lined with threadlike leaves. The short inflorescence bears spikelets under a centimeter long.
Sphenopholis obtusata is a species of grass known by the common names prairie wedgescale and prairie wedge grass. It is native to North America where it is widespread across southern Canada and the United States. It occurs in many types of habitat, including prairie, marshes, dunes, and disturbed areas.
Aristida chaseae is a rare species of grass known by the common name Chase's threeawn. It is endemic to Puerto Rico, where it is known from two locations in the Cabo Rojo National Wildlife Refuge and the Sierra Bermeja. It is a federally listed endangered species of the United States. It cannot compete with introduced species of grasses, such as Brachiaria subquadripara, which are invading its habitat.
Aristida portoricensis is a rare species of grass known by the common name pelos del diablo. It is endemic to Puerto Rico, where it is known from two locations, one in a residential area of Mayagüez and one in the Sierra Bermeja. Two other known sites have been extirpated by development of the habitat. It is a federally listed endangered species of the United States.
Dicerandra cornutissima is a rare species of flowering plant in the mint family known by the common names longspurred mint, longspurred balm, and Robin's mint. It is endemic to Florida in the United States. It is found in Marion County, and possibly Sumter County, but it may have been totally extirpated from the latter. There are 12 known occurrences remaining as of 2017, down from 15 in 2000. The plant was federally listed as an endangered species in 1985.
Poa paludigena is a species of grass known by the common names bog bluegrass, marsh bluegrass, slender marsh bluegrass, and Patterson's bluegrass. It is native to the northeastern United States.
Amphicarpum muehlenbergianum is a species of grass known by the common names blue maidencane, Muhlenberg maidencane, and goobergrass. It is native to the southeastern United States.
Aristida purpurascens is a species of grass known by the common name arrowfeather threeawn. It is native to eastern North America. One of the three varieties has a distribution extending south into Honduras.
Aristida rhizomophora is a species of grass known by the common name Florida threeawn. It is endemic to Florida in the United States.
Aristida tuberculosa, common names seaside threeawn, seabeach needlegrass, beach three-awned grass and beach needlegrass, is annual plant native to the United States.
Aristida longespica is a species of grass known by the common name slimspike threeawn. Aristida longespica var. geniculata is listed as a species of special concern in the State of Connecticut.
