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Bouteloua Lag.

Kingdom: Plantae Rank: Genus Parent: Poaceae Status: Valid

Common Names:

  • GRAMA GRASS - English, United States of America

Morphological Description

Diagnosis: Perennials or annuals (B. aristidoides and B. barbata); culms erect, tufted; rhizomes present or absent; leaves mostly basal; ligule a fringe of hairs; leaf blades usually flat, involute apically; inflorescences of 1–many short, spike-like or spikelet-like branches; disarticulation at branch bases or above glumes; spikelets sessile, with 1 perfect floret and 1 or more staminate or neuter florets above; glumes 1-veined; lemmas 3-veined, often short-awned.


Notes: An American genus of ca. 40 species (Watson & Dallwitz 1992; Wipff 2003d) of open habitats ranging from Canada to Argentina, with the center of diversity in Mexico. It includes a number of valuable native forage grasses; some are also used as ornamentals. All species are C₄ plants with typical Kranz leaf anatomy (Gould 1979). These adaptations allow more effective capture of carbon dioxide and thus reduced loss of water through transpiration (since stomata do not have to be as open for gas exchange), an advantage in arid environments. The genus has traditionally been divided into two subgenera (see key and synonymy below), Bouteloua (ca. 24 species) and Chondrosum (ca. 14 species), these sometimes treated as sections or as distinct genera (e.g., Clayton 1982; Clayton & Renvoize 1986; Pohl 1994b). However, recent molecular and morphological evidence (Columbus et al. 1998, 2000; Columbus 1999a, 1999b) suggests that neither Bouteloua nor its two subgenera are monophyletic and that the circumscripton of Bouteloua should be expanded to include species in a number of small satellite genera including Buchloe, BUFFALO GRASS. However, until confirming evidence is available, we are maintaining Buchloe as a distinct monotypic genus. While GRAMA GRASSES are very valuable as forage, hydrogen cyanide production in new growth after rains is known in a few species, posing a potential threat to grazing animals (Hilsenbeck in Powell 1994). The grains are eaten by native birds, including turkey, quail, and dove (Stubbendieck et al. 1997). The common name, grama, is derived from a Spanish word for a type of grass. (Named for Claudio Boutelou, 1774–1842, a Spanish writer on floriculture and agriculture) (subfamily Chloridoideae, tribe Cynodonteae)