Achnatherum contractum - (B.L. Johnson) Barkworth
Contracted Ricegrass
Synonym(s): Oryzopsis contracta (B.L. Johnson) Schlechter ;Oryzopsis hymenoides var. contracta B.L. Johnson
Taxonomic Status: Accepted
Related ITIS Name(s): Achnatherum contractum (B.L. Johnson) Barkworth (TSN 507937)
Unique Identifier: ELEMENT_GLOBAL.2.138707
Element Code: PMPOA4J0E0
Informal Taxonomy: Plants, Vascular - Flowering Plants - Grass Family
 
Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Monocotyledoneae Cyperales Poaceae Achnatherum
Check this box to expand all report sections:
Concept Reference
Help
Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Oryzopsis contracta
Taxonomic Comments: Treated as Achnantherum contractum by Kartesz (1999); was treated as Oryzopsis contracta by him in 1994. Johnson (1955) named it as a variety of O. hymenoides, and later elevated it to species (Schecter & Johnson 1966, 1968). It is of hybrid origin (O. h. X O. micrantha), recognized by its open panicle with appressed pedicels.
Conservation Status
Help

NatureServe Status

Global Status: G3G4
Global Status Last Reviewed: 16Dec1997
Global Status Last Changed: 13Apr1998
Rounded Global Status: G3 - Vulnerable
Reasons: Oryzopsis contracta is known from a number of occurrences and has a scattered distribution and low threats throughout its range of Colorado, Utah, Wyoming, and Montana.
Nation: United States
National Status: N3N4

U.S. & Canada State/Province Status
United States Colorado (SU), Montana (S3?), Utah (S1), Wyoming (S3S4)

Other Statuses

NatureServe Global Conservation Status Factors

Range Extent Comments: Chiefly in the southern half of Wyoming; also in Montana, Utah, and northern Colorado.

Population Size Comments: Estimated totals are roughly 100,000 in Montana.

Overall Threat Impact Comments: It occupies what is generally secondary range, but is potentially threatened under heavy grazing and noxious weed invasion.

Short-term Trend: Unknown

Intrinsic Vulnerability Comments: It occupies a wide range of grassland habitats over its range, relatively resilient.

Other NatureServe Conservation Status Information

Distribution
Help
Global Range: Chiefly in the southern half of Wyoming; also in Montana, Utah, and northern Colorado.

U.S. States and Canadian Provinces
Color legend for Distribution Map

U.S. & Canada State/Province Distribution
United States CO, MT, UT, WY

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
WY Albany (56001)*, Carbon (56007), Fremont (56013), Hot Springs (56017), Natrona (56025), Park (56029), Sublette (56035), Sweetwater (56037), Teton (56039), Uinta (56041)*, Washakie (56043)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
10 Clarks Fork Yellowstone (10070006)+, Upper Wind (10080001)+, Little Wind (10080002)+, Muskrat (10080004)+, Lower Wind (10080005)+, Upper Bighorn (10080007)+, Nowood (10080008)+, Shoshone (10080014)+, South Fork Powder (10090203)+, Medicine Bow (10180004)+*, Little Medicine Bow (10180005)+, Sweetwater (10180006)+, Middle North Platte-Casper (10180007)+, Upper Laramie (10180010)+*, Lower Laramie (10180011)+*, Horse (10180012)+*, Upper Lodgepole (10190015)+*
14 Upper Green (14040101)+, Upper Green-Slate (14040103)+, Big Sandy (14040104)+, Bitter (14040105)+, Upper Green-Flaming Gorge Reservoir (14040106)+, Blacks Fork (14040107)+, Great Divide closed basin (14040200)+
17 Gros Ventre (17040102)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Help
General Description: Contracted Indian ricegrass is a tufted perennial with glabrous stems 30-64 cm (12-28 in) tall. The infloresence is a panicle with branches that are intially contracted, hence the common name, but which become stiffly spreading at maturity. Spikelets are single flowered, slender, and 1.5 cm (3/4 in) long. Each hardened narrowly elliptic spikelet, 5-7 mm long, has 2 glumes enclosing the short-hairy lemma with an awn, 6-12 mm long.
Diagnostic Characteristics: Oryzopsis contracta could easily be confused with the common Indian ricegrass, O. hymenoides. However, the latter has a more egg-shaped spikelet, shorter awns, 3-8 mm long, and the hairs of the lemma extend well beyond its apex.
Habitat Comments: Open areas in sagebrush and grasslands, clay slopes, and buttes; not restricted to a specific substrate.
Economic Attributes Not yet assessed
Help
Management Summary Not yet assessed
Help
Population/Occurrence Delineation Not yet assessed
Help
Population/Occurrence Viability
Help
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
Help
Authors/Contributors
Help
NatureServe Conservation Status Factors Edition Date: 08Dec1987
NatureServe Conservation Status Factors Author: NEIGHBOURS, M.L., rev. D. Gries (1997), B. Heidel (1999).
Element Ecology & Life History Edition Date: 08Nov1994
Element Ecology & Life History Author(s): JM

Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

References
Help
  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Kartesz, J.T., and R. Kartesz. 1980. A synonymized checklist of the vascular flora of the United States, Canada and Greenland. Vol. 2. The biota of North America. Univ. of North Carolina Press, Chapel Hill. 500 pp.

Use Guidelines & Citation

Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of November 2016.
Note: This report was printed on

Trademark Notice: "NatureServe", NatureServe Explorer, The NatureServe logo, and all other names of NatureServe programs referenced herein are trademarks of NatureServe. Any other product or company names mentioned herein are the trademarks of their respective owners.

Copyright Notice: Copyright © 2017 NatureServe, 4600 N. Fairfax Dr., 7th Floor, Arlington Virginia 22203, U.S.A. All Rights Reserved. Each document delivered from this server or web site may contain other proprietary notices and copyright information relating to that document. The following citation should be used in any published materials which reference the web site.

Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

Restrictions on Use: Permission to use, copy and distribute documents delivered from this server is hereby granted under the following conditions:
  1. The above copyright notice must appear in all copies;
  2. Any use of the documents available from this server must be for informational purposes only and in no instance for commercial purposes;
  3. Some data may be downloaded to files and altered in format for analytical purposes, however the data should still be referenced using the citation above;
  4. No graphics available from this server can be used, copied or distributed separate from the accompanying text. Any rights not expressly granted herein are reserved by NatureServe. Nothing contained herein shall be construed as conferring by implication, estoppel, or otherwise any license or right under any trademark of NatureServe. No trademark owned by NatureServe may be used in advertising or promotion pertaining to the distribution of documents delivered from this server without specific advance permission from NatureServe. Except as expressly provided above, nothing contained herein shall be construed as conferring any license or right under any NatureServe copyright.
Information Warranty Disclaimer: All documents and related graphics provided by this server and any other documents which are referenced by or linked to this server are provided "as is" without warranty as to the currentness, completeness, or accuracy of any specific data. NatureServe hereby disclaims all warranties and conditions with regard to any documents provided by this server or any other documents which are referenced by or linked to this server, including but not limited to all implied warranties and conditions of merchantibility, fitness for a particular purpose, and non-infringement. NatureServe makes no representations about the suitability of the information delivered from this server or any other documents that are referenced to or linked to this server. In no event shall NatureServe be liable for any special, indirect, incidental, consequential damages, or for damages of any kind arising out of or in connection with the use or performance of information contained in any documents provided by this server or in any other documents which are referenced by or linked to this server, under any theory of liability used. NatureServe may update or make changes to the documents provided by this server at any time without notice; however, NatureServe makes no commitment to update the information contained herein. Since the data in the central databases are continually being updated, it is advisable to refresh data retrieved at least once a year after its receipt. The data provided is for planning, assessment, and informational purposes. Site specific projects or activities should be reviewed for potential environmental impacts with appropriate regulatory agencies. If ground-disturbing activities are proposed on a site, the appropriate state natural heritage program(s) or conservation data center can be contacted for a site-specific review of the project area (see Visit Local Programs).

Feedback Request: NatureServe encourages users to let us know of any errors or significant omissions that you find in the data through (see Contact Us). Your comments will be very valuable in improving the overall quality of our databases for the benefit of all users.