Grass
Grasses of the Mixed Grass Prairie
Within Wind Cave National Park you can find an excellent example of a mixed grass prairie. A mixed grass prairie is an ecotone characterized by a mixture of the tall grass species of the eastern tall grass prairie and the short grass species of the western high plains. It is a meeting place, an area that is constantly changing. The dominance of the different types of grasses depends on the amount of moisture received in any given year. With abundant rainfall the tall grasses will dominate because they need more moisture. They are generally found in the valleys of the park. The short grasses are adapted to less moisture. These grasses are found on the dryer, south facing slopes of the park.
    Of all of the flowering plants of the prairie, grasses are often overlooked. They are the main component of the prairie, making up about 80% of the biomass. Forbs constitute the other 20%.
    This guide contains grasses that have been identified in the park or would be expected to be found here. Please feel free to report any grasses you find that are not on this list. Flowering times are noted for each species. 

Grass Characteristics  
(A) Annual: A plant that does not live more than 1 year.
(P) Perennial: A plant that can live for more than 2 years.
(W) Warm Season: A plant that grows in spring and summer, flowers in summer or fall.
(C) Cool Season: A plant that grows and flowers in spring and early summer, grows slowly or becomes dormant during the hot part of the summer, and may resume growth in the fall as the weather cools.
(S) Sod Grass: A grass that forms sod by means of rhizomes or stolons.
(B) Bunch Grass: A grass that takes on the characteristic shape of a bunch or tuft.
(N) Native: Grass that was part of the original vegetation of the area.
(I) Introduced: Grass not native to North America, intentionally or unintentionally brought in by humans.

 

Tall Grasses - 3 feet tall or taller (Average heights; individual plant size may vary with growing conditions.) A P W C S B N I
Agropyron intermedium - Intermediate wheatgrass (Jun-Aug)   *   * *     *
Agrostis exarata - Spikebent (Jul-Aug)   * *   *   *  
Agrostis stolonifera - Redtop (Jun-Jul)   *   * *   *  
Andropogon gerardii - Big bluestem (Jul-Aug)   * *   *   *  
Calamovilfa longifolia - Prairie sandreed (Aug-Sep)   * *   *   *  
Dactylis glomerata - Orchard grass (May-Oct)   *   *   *   *
Elymus canadensis - Canada wild rye (Jul-Aug)   *   *   * *  
Panicum virgatum - Switchgrass (Jul-Sep)   * *   *   *  
Phalaris arundinacea - Reed canarygrass (May-Jul)   *   * *   *  
Sorghastrum nutans - Indiangrass (Aug-Sep)   * *   *   *  
Spartina pectinata - Prairie cordgrass (Jul-Aug)   * *   *   *  
Sporobolus asper - Prairie dropseed (Jul-Sep)   * *     * *  
Sporobolus cryptandrus - Sand dropseed (Aug-Sep)   * *     * *  

 

Mid Grasses - 1 to 3 feet tall A P W C S B N I
Agropyron caninum - Slender wheatgrass (Jul-Aug)   *   *   * *  
Agropyron cristatum - Crested wheatgrass (Jun-Jul)   *   *   *   *
Agropyron spicatum - Bluebunch wheatgrass (Jun-Jul)   *   *   * *  
Schizachyrium scoparium - Little bluestem (Aug-Sep)   * *     * *  
Bouteloua curtipendula - Side-oats grama (Jul-Aug)   * *     * *  
Bromus commutatus - Hairy chess (May-Jun)
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Bromus inermis - Smooth brome (May-Jun)   *   * *     *
Danthonia spicata - Poverty Grass (Jul-Aug)   *   * *   *  
Echinochloa crusgalli - Barnyard grass (Jul-Sep) *   *   *     *
Hordeum jubatum - Foxtail barley (Jun-Jul)
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Koeleria pyramidata - Junegrass (Jun-Jul)   *   *   * *  
Muhlenbergia racemosa - Marsh muhly (Aug-Sep)   * *   *   *  
Oryzopsis asperifolia - Rough-leaved ricegrass (May-Jun)   *   *   * *  
Oryzopsis hymenoides - Indian ricegrass (Jun-Jul)   *   *   * *  
Pascopyrum smithii - Western wheatgrass (Jun-Jul)
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Phleum pratense - Timothy (Jun-Jul)   *   *   *   *
Poa compressa - Canada bluegrass (Jun-Jul)   *   * *     *
Poa canbyi - Canby's bluegrass (Jun-Jul)   * *     * *  
Poa interior - Inland bluegrass (Jun-Jul)   *   *   * *  
Poa pratensis - Kentucky bluegrass (Jun-Jul)   *   *   * * *
Sitanion hystrix - Squirreltail (Jun-Jul)   *   *   * *  
Stipa comata - Needle-and-thread (May-Jul)   *   *   * *  
Stipa spartea - Porcupine grass (May-Jun)   *   *   * *  
Stipa viridula - Green needlegrass (Jul-Aug)   *   *   * *  

 

Short Grasses - Less than 1 foot tall A P W C S B N I
Aristida longiseta - Red threeawn (Aug-Sep)   * *     * *  
Bouteloua gracilis - Blue grama (Jul-Aug)   * *   *   *  
Bouteloua hirsuta - Hairy grama (Jul-Aug)   * *   *   *  
Bromus japonicus - Japanese brome (Jun-Aug) *     *   *   *
Bromus tectorum - Cheatgrass (May-Jun) *     * *     *
Buchloe dactyloides - Buffalo grass (Jun-Jul)   * *   *   *  
Eragrostis cilianensis - Stinkgrass (Jul-Aug) *   *         *
Festuca octoflora - Sixweeks fescue (May-Jun) *     *     *  
Hordeum pusillum - Little barley (May-Jun) *     *     *  
Muhlenbergia cuspidata - Plains muhly (Jul-Aug)   * *       *  
Poa arida - Plains bluegrass (Apr-Jun)   *   *   * *  
Poa sandbergii - Sandberg's bluegrass (Apr-Jun)   * *     * *  

Wind Cave National Park Nature & Science

Page Last Updated: Saturday, April 29, 2006 3:29 PM
Web Author: Jim Pisarowicz