Species Factsheets

Bouteloua curtipendula

Side-oats Grama

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State Status: Pennsylvania Threatened (PT)
PBS Status: Pennsylvania Threatened (PT)
Federal Status:

Global Rank: G5 rank interpretation
State Rank: S2

Did You Know?

This state grass of Texas provides food and nesting material for birds as well as graze for animals.

Bouteloua curtipendula


Side-oats grama (Bouteloua curtipendula) is a perennial grass that grows from .5-1m tall. This attractive species grows from slender rhizomes. The leaves are linear and elongate, rough above and on the edges, smooth or finely hairy beneath, and about 2-7mm wide. The flowers are arranged on a narrow, unbranched inflorescence which has fifteen to fifty spikelets that tend to hang down to one side. When the flowers bloom in August and September, bright orange anthers may be seen dangling from the spikelets.

Rank Justification

Imperiled in the nation or state because of rarity due to very restricted range, very few populations (often 20 or fewer), steep declines, or other factors making it very vulnerable to extirpation from the nation or state.


The PA Biological Survey considers side-oats grama to be a species of special concern, based on the relatively few occurrences that have been confirmed, the specialized habitat, and the management required to retain the proper successional stage at its occurrences. It has been assigned a rarity status of Threatened.


The species grows in dry, open, rocky, places, especially on limestone and serpentine geology.

Survey Dates

Flowers August - September


In Pennsylvania, most of the known occurrences are in the central and southeastern counties.



Maintenance of known occurrences of side-oats grama usually require special management, such as prescribed burning or regular mowing, in order to prevent succession and keep exotic species and woody plants in check.

Conservation Status Map


Map Legend

NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org.


  • NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available at https://www.natureserve.org/explorer
  • Pennsylvania Natural Heritage Program. 2018.
  • Rhoads, A.F. and W.M. Klein, Jr. 1993. The Vascular Flora of Pennsylvania. American Philosophical Society, Philadelphia, Pennsylvania. Rhoads, A.F. and T.A. Block.
  • 2007. The Plants of Pennsylvania: An Illustrated Manual. 2nd edition. University of Pennsylvania Press, Philadelphia, Pennsylvania.
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