''Aristida'' is a very nearly
cosmopolitan
Cosmopolitan may refer to:
Food and drink
* Cosmopolitan (cocktail), also known as a "Cosmo"
History
* Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953
Hotels and resorts
* Cosmopoli ...
genus of plants in the
grass family
Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns and ...
. ''Aristida'' is distinguished by having three
awn
AWN may stand for:
* Awn Access to Justice Network in Gaza Strip, Legal Aid Network operate in Gaza Strip, Palestine
* Animation World Network, an online organization for animators
* Avant Window Navigator, a dock-like bar that tracks open windows ...
s (bristles) on each
lemma
Lemma may refer to:
Language and linguistics
* Lemma (morphology), the canonical, dictionary or citation form of a word
* Lemma (psycholinguistics), a mental abstraction of a word about to be uttered
Science and mathematics
* Lemma (botany), a ...
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. The name ''Aristida'' is derived from the
Latin "
arista
Arista may refer to:
Organizations
*Arista Networks, a software defined networking company
*Arista Records, an American record label, division of Sony Music
**Arista Nashville, a record label specializing in country music
*Arista (honor society) ...
", meaning "awn".
They are characteristic of
semiarid grassland. The
Wiregrass Region
The Wiregrass region or Wiregrass country is an area of the Southern United States encompassing parts of southern Georgia, southeastern Alabama, and the Florida Panhandle. The region is named for the native ''Aristida stricta'', commonly known ...
of
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
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
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
, and the
xeric grasslands around
Lake Turkana
Lake Turkana (), formerly known as Lake Rudolf, is a lake in the Kenyan Rift Valley, in northern Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake. B ...
in
Africa. Local increases in the abundance of wiregrasses is a good indicator of
overgrazing, as
livestock avoid them.
Description
''Aristida'' stems are ascending to erect, with both basal and cauline leaves. The leaves may be flat or inrolled, and the basal leaves may be tufted. The
inflorescences may be either
panicle
A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...
-like or
raceme
A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the s ...
-like, with spiky branches. The
glume
In botany, a glume is a bract (leaf-like structure) below a spikelet in the inflorescence (flower cluster) of grasses (Poaceae) or the flowers of sedges (Cyperaceae). There are two other types of bracts in the spikelets of grasses: the lemma and ...
s of a spikelet are narrow lanceolate, usually without any awns, while the lemmas are hard, three-veined, and have the three awns near the tip. The awns may be quite long; in
''A. purpurea '' var. ''longiseta'' they may be up to 10 cm.
Species
Selected species include:
See also
* ''
Puccinia aristidae
''Puccinia aristidae'' is a plant pathogen that causes rust on ''Aristida'', spinach and primula
''Primula'' () is a genus of herbaceous flowering plants in the family Primulaceae. They include the primrose ('' P. vulgaris''), a familiar wild ...
'', a
plant pathogen
Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomyc ...
ic
urediniomycete fungus first described from three-awn grass
*
List of Poaceae genera
References
{{Taxonbar, from=Q311128
Poaceae genera
Taxa named by Carl Linnaeus