Greene's Tuctoria
See  photo info below

Sacramento Fish & Wildlife Office
Species Account

GREENE'S TUCTORIA
(Tuctoria greenei)

CLASSIFICATION: Federal Endangered Species (Federal Register 62:14338 (PDF); March 26, 1997).

This species was listed as rare 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.

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:

Greene's tuctoria (Tuctoria greenei), which is also known as Greene's Orcutt grass or awnless spiralgrass, is a small, tufted annual in the grass family (Poaceae). The plant has several to many stems 2-6 inches tall, each ending in a spike-like inflorescence that may be partly enfolded in the upper leaf. The lemmas (bracts) are strongly curved and more or less truncate at the apex.

The genus Tuctoria, which includes the endangered Solano grass (Tuctoria mucronata), is distinguished from the closely related Orcutt grasses (Orcuttia), several of which are threatened or endangered, by the spiral arrangement of the spikelets (flowers) and other characteristics of its flower parts.

See Hickman (1993) in General Information about California Plants, below, for a detailed description of these species.

DISTRIBUTION:

Tuctoria greenei is currently found in widely separated occurrences in Butte, Merced, Shasta and Tehama Counties. Sixty percent of the extant occurrences are in the Vina Plains area of Tehama and Butte Counties. Eastern Merced County has about 30 percent of the known occurrences. Other occurrences are located in Glenn and Shasta Counties. The species has been extirpated from Fresno, Madera, San Joaquin, Stanislaus and Tulare Counties.

THREATS:

Primary threats include agricultural conversion, inappropriate livestock grazing and urbanization.

Soil disturbance from cattle grazing combined with competition from the introduced annual grasses and other nonnative species appear to adversely affect many of the extant populations. Greene's tuctoria grows in the margins of vernal pools making it susceptible to livestock trampling and competition from nonnative weeds. All remaining populations are subject to grazing. However, grazing can help control invasive species if timed correctly.

One potential factor unique to this and some other vernal pool plant species may be decimation by grasshopper outbreaks. Grasshoppers have been noted consuming entire populations of Tuctoria greenei before they set seed

REFERENCES FOR ADDITIONAL INFORMATION:

General Information about California Plants

Photo credit: Hitchcock, A.S. (rev. A. Chase). 1950. Manual of the grasses of the United States. USDA Misc. Publ. No. 200. Washington, DC. 1950.

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