Slender Orcutt Grass
See photo info below

Sacramento Fish & Wildlife Office
Species Account

SLENDER ORCUTT GRASS
(Orcuttia tenuis)

Slender Orcutt Grass
See photo info

CLASSIFICATION: Federal Threatened Species (Federal Register 62:14338 (pdf); March 26, 1997).

This species was listed as endangered by the California Department of Fish and Game in September 1979. The California Native Plant Society has placed it on List 1B (rare or endangered throughout its range).

CRITICAL HABITAT: Originally designated in Federal Register 68:46683 pdf; August 6, 2003.
The designation was revised in 70:46923 pdf; August 11, 2005. Species by unit designations were published in 71:7117 (pdf) February 10, 2006.

RECOVERY PLAN: Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon

DESCRIPTION:

Slender Orcutt grass (Orcuttia tenuis) is a small, weakly tufted annual in the grass family (Poaceae). The plant has several stems 2-6 inches tall, ending in an elongate inflorescence of scattered spikelets. The lemmas (bracts) are deeply cleft into fine, equal-length, prominent teeth that are sharp-pointed or short-awned. Foliage is grayish, with sparse hairs.

Slender Orcutt grass and hairy Orcutt grass (Orcuttia pilosa) grow together over a portion of their respective ranges but are readily distinguished. Slender Orcutt grass has fairly slender stems that often branch from their upper nodes. Spikelets are evenly spaced, not densely crowded. Hairy Orcutt grass stems branch only from lower nodes. Upper spikelets are densely crowded. As the species' name implies, it has more hairs. See Hickman (1993) in General Information about California Plants below.

DISTRIBUTION:

Slender Orcutt grass occurs in valley grassland and blue oak woodland. It grows in vernal pools on remnant alluvial fans and high stream terraces and recent basalt flows. It has some ability to colonize artificial habitats, such as the margins of stock ponds.

The primary area of concentration is in the vicinity of Dales, Tehama County. A secondary area of concentration is the Modoc Plateau Vernal Pool Region in Lassen, Plumas, Shasta and Siskiyou Counties. There are a few occurrences in the Lake-Napa and Southeastern Sacramento Valley Vernal Pool Regions. See the Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon for detailed information about current distribution.

THREATS:

Habitat loss and fragmentation are the largest threats to the survival and recovery of vernal pool species. Loss of habitat generally results from urbanization, agricultural conversion and mining.

Habitat loss also occurs in the form of habitat alteration and degradation as a result of changes to natural hydrology, invasive species, incompatible grazing regimes, infrastructure projects (e.g., roads, water storage and conveyance, utilities), recreational activities (e.g., off-highway vehicles and hiking), erosion, contamination and inadequate management and monitoring.

A number of specific threats are also continuing. In particular, urbanization is a continuing threat to populations in the vicinity of Redding and Sacramento. Off-road vehicle use is a particular problem near Redding and in forested areas of the Modoc Plateau. And despite the comparatively wide range of the species, small population size is of concern in the Lake-Napa Vernal Pool Region and the Millville Plains-Stillwater Plains area.

REFERENCES FOR ADDITIONAL INFORMATION:

U.S. Fish & Wildlife Service. 1997. Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for Three Plants and Threatened Status for Five Plants From Vernal Pools in the Central Valley of California. (pdf) Portland, Oregon.

U.S. Fish and Wildlife Service. 2003. Endangered and Threatened Wildlife and Plants; Final Designation of Critical Habitat for Four Vernal Pool Crustaceans and Eleven Vernal Pool Plants in California and Southern Oregon Vernal pool crustaceans and plants in California and Oregon. Portland, Oregon.

U.S. Fish and Wildlife Service. 2005. Endangered and Threatened Wildlife and Plants; Final Designation of Critical Habitat for Four Vernal Pool Crustaceans and Eleven Vernal Pool Plants in California and Southern Oregon; Evaluation of Economic Exclusions From August 2003 Final Designation; Final Rule. Portland, Oregon.

U.S. Fish and Wildlife Service. 2006. Endangered and Threatened Wildlife and Plants: Designation of Critical Habitat for Four Vernal Pool Crustaceans and Eleven Vernal Pool Plants; Final Rule. Portland, Oregon.

U.S. Fish and Wildlife Service. 2005. Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon. Portland, Oregon.

General Information about California Plants

Photo credits:
Close-up © 2000 Robert E. Preston, Ph.D Calphoto ID: 0000 0000 0102 0101
Photo of whole plant © 1991 Dean Wm. Taylor Calphoto ID: 0000 0000 0801 0418

Prepared by Endangered Species Div., Sacramento Fish & Wildlife Office, U.S. Fish & Wildlife Service