Bouteloua curtipendula spikelets Troy Weldy

Bouteloua curtipendula spikelets
Troy Weldy

Monocotyledoneae (Monocots)
Poaceae (Grass Family)
State Protection
Federal Protection
Not Listed
State Conservation Status Rank
Global Conservation Status Rank


Did you know?

Side-oats grama is a very widespread and common grass west of New York but only occurs here in fewer than ten places. Many of them are close to or along current or historical railroad lines. It is one of the most beautiful and easy-to-recognize grasses in New York.

State Ranking Justification

There are eight existing populations, half of them good or excellent. The other half are small or under threat. There are about 10 historical populations and most of those are probably extirpated.

Short-term Trends

The short-term trend appears good as most current populations have have not changed in size over the last 30 years.

Long-term Trends

The long-term trend has been somewhat negative as many of the historical populations in the Hudson River Valley have not been found again. This was a result of habitat succession and the introduction of weedy species through the suppression of fire and other human disturbances.

Conservation and Management


Populations are moderately threatened by succession and human disturbance which has introduced weedy species such as phragmites and European herbs. Unprotected populations may be threatened by development at the sites.

Conservation Strategies and Management Practices

The control of invasive species is important in the open habitat where this grass occurs.

Research Needs

There seems to be a specific rock and soil type that the species prefers, otherwise it would be much more common in the state. There is a need to understand these habitat preferences. Most of the occurrences are also near existing or old railroad tracks and this correlation needs to be studied.



In New York this species is strongly associated with dry limestone-derived soils, as well as with disturbance, both natural and artificial, since it is also prefers open habitats. It occurs at riverside bluffs, shale cliffs and barrens, cedar glades, and limestone pavements as well as abandoned sandpits and pastures, railroads, and powerlines. (New York Natural Heritage Program 2007). Dry hills and plains (Fernald 1970). Dry woods (Gleason & Cronquist 1991).

Associated Ecological Communities

  • Alvar pavement grassland (guide)
  • Calcareous cliff community* (guide)
  • Calcareous red cedar barrens (guide)
  • Calcareous talus slope woodland* (guide)
  • Limestone woodland* (guide)
  • Northern white cedar rocky summit*
  • Red cedar rocky summit (guide)
  • Shale cliff and talus community* (guide)

Associated Species

  • Asclepias viridiflora (green milkweed)
  • Carex bicknellii (Bicknell's sedge)
  • Carex crawei (Crawe's sedge)
  • Centaurea melitensis
  • Juniperus communis
  • Liatris borealis
  • Lonicera morrowii (Morrow's honeysuckle)
  • Melilotus albus (white sweet-clover)
  • Monarda fistulosa
  • Ostrya virginiana (hop hornbeam, ironwood)
  • Phleum pratense
  • Rhamnus cathartica (European buckthorn)
  • Schizachyrium scoparium
  • Spiranthes cernua (nodding ladies'-tresses)
  • Sporobolus heterolepis (prairie dropseed)
  • Sporobolus neglectus (small dropseed)
  • Toxicodendron radicans


New York State Distribution

In New York Side-oats Grama is found in scattered locations primarily from Long Island and the Hudson Valley, as well as a few sites on alvar or limestone regions in Western New York.

Global Distribution

Side-oats Grama is found throughout most of the United States, as well as Ontario, and Saskatchewan.

Best Places to See

  • Wyatts Riverside Bluffs (Schenectady County)

Identification Comments

General Description

Side-oats grama is a attractive perennial grass with erect stems up to 1m tall (usually less). The numerous spikes are relatively large (.8-2cm long) and well-spaced along a mostly 1-sided raceme.

Best Life Stage for Proper Identification

Side-oats Grama is most easily identified when flowering or fruiting. The distinctive flower stalks may sometimes be recognized even in winter.

Similar Species

There are no other species of Bouteloua in New York, and the overall form of this grass is quite distinctive.

Best Time to See

Side-oats grama flowers in mid-summer and the fruits persist from mid-July through the fall.

  • Flowering
  • Fruiting

The time of year you would expect to find Side-oats Grama flowering and fruiting in New York.

Side-oats Grama Images


Side-oats Grama
Bouteloua curtipendula var. curtipendula None

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Monocotyledoneae (Monocots)
        • Order Cyperales
          • Family Poaceae (Grass Family)

Additional Resources

Best Identification Reference

Flora of North America Editorial Committee. 2003. Flora of North America, North of Mexico. Volume 25. Magnoliophyta: Commelinidae (in part): Poaceae, part 2. Oxford University Press, New York. 783 pp.

Other References

Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.

Hitchcock, A.S. 1951. Manual of the grasses of the United States. 2nd edition revised by Agnes Chase. [Reprinted, 1971, in 2 vols., by Dover Publications, Incorporated, New York.]

Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.

New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.

New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.

Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.

Rhoads, Ann F. and Timothy A. Block. 2000. The Plants of Pennsylvania, an Illustrated Manual. University of Pennsylvania Press, Philadelphia, PA.

Voss, E.G. 1972. Michigan Flora, Part I. Gymnosperms and Monocots. Cranbrook Institute of Science Bulletin 55 and the University of Michigan Herbarium. Ann Arbor. 488 pp.

Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research University of South Florida]. New York Flora Association, Albany, New York

Weldy, Troy W. and David Werier. 2005. New York Flora Atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research. University of South Florida]. New York Flora Association, Albany, NY. Available on the web at (


About This Guide

Information for this guide was last updated on: January 18, 2008

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Bouteloua curtipendula var. curtipendula. Available from: Accessed March 20, 2019.

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