Bouteloua gracilis (blue grama) is a long-lived,warm-season (C4) perennial grass,native to North America.It is most commonly found from Alberta,Canada,east to Manitoba and south across the Rocky Mountains,Great Plains,and U.S.Midwest states,onto the northern Mexican Plateau in Mexico.Blue grama accounts for most of the net primary productivity in the shortgrass prairie of the central and southern Great Plains.It is a green or greyish,low-growing,drought-tolerant grass with limited maintenance.Blue grama grows on a wide array of topographic positions,and in a range of well-drained soil types,from fine- to coarse-textured.Blue grama has green to greyish leaves less than 3 mm (0.1 in) wide and 1 to 10 in (25 to 250 mm) long.The overall height of the plant is 6 to 12 in (15 to 30 cm) at maturity.The flowering stems (culms) are 7 to 18 in (18 to 46 cm) long.Typically,two comb-like spikes,each with 20 to 90 spikelets,extend out at a sharp angle from the flowering stem Each spikelet is 5 to 6 mm (0.20 to 0.24 in) long.The one fertile floret has a lemma (bract) 5 to 5.5 mm (0.20 to 0.22 in) long,with three short awns (bristles) at the tip,and one reduced sterile floret about 2 mm (0.08 in) long with three awns about 5 mm (0.2 in) long.The roots generally grow 12 to 18 in (30 to 46 cm) outwards,and 3 to 6.5 ft (0.9 to 2.0 m) deep.Blue grama is readily established from seed,but depends more on vegetative reproduction via tillers.Seed production is slow,and depends on soil moisture and temperature.Seeds dispersed by wind only reach a few meters (6 ft);farther distances are reached with insects,birds,and mammals as dispersal agents.Seedling establishment,survival,and growth are greatest when isolated from neighboring adult plants,which effectively exploit water in the seedling's root zone.Successful establishment requires a modest amount of soil moisture during the extension and development of adventitious roots.Established plants are grazing-,cold-,and drought-tolerant,though prolonged drought leads to a reduction in root number and extent.They employ an opportunistic water-use strategy,rapidly using water when available,and becoming dormant during less-favorable conditions.In terms of successional status,blue grama is a late seral to climax species.Recovery following disturbance is slow and depends on the type and extent of the disturbance.

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