Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Chorizanthe rigida, Rigid Spineflower

Chorizanthe rigida, Rigid SpineflowerChorizanthe rigida, Rigid SpineflowerChorizanthe rigida, Rigid SpineflowerChorizanthe rigida, Rigid Spineflower

Scientific Name: Chorizanthe rigida
Common Name: Rigid Spineflower
Also Called: Devil's Spineflower, Spine Herb, Spiny Chorizanthe, Turkshead
Family: Polygonaceae, Buckwheat Family
Synonyms: (Acanthogonum rigidum)
Status: Native
Duration: Annual
Size: Up to 4 or 5 inches more or less.
Growth Form: Forb/herb; stems greenish, erect, dichotomously branched, foliage leaves in a basal rosette soon disappearing.
Leaves: Green; with ¼ inch petiole, opposite; shape variable, elliptical to oblanceolate, hairy, basal leaves die-off soon.
Flower Color: Yellow; sepals and petals collectively referred to as a perianth; hairy.
Flowering Season: March to May; February to June in California.
Elevation: 2,500 feet or lower.

Habitat Preferences: Common in gravelly or rocky flats and slopes, desert scrub.

Recorded Range: Rigid Spineflower is found in the southwestern United States in AZ, CA, NV, UT. In Arizona it is found n the western ⅔ of the state and in Graham and Cochise counties. Rigid Spineflower is also native to Baja California and northwest Mexico

North America & US County Distribution Map for Chorizanthe rigida.

U.S. Weed Information: No information available.
Invasive/Noxious Weed Information: No information available.
Wetland Indicator: No information available.
Threatened/Endangered Information: No information available.

Genus Information: In North America, USDA database lists 33 species for Chorizanthe in the southwest and western parts of the United States: AZ, CA, ID, NV, OR, UT, WA. World-wide, The Plant List includes 64 accepted species names.

In the southwestern United States for Chorizanthe, there are approximately; 4 species in Arizona and Nevada, 34 species in California, 1 species in New Mexico, zero species in Texas, and 3 species in Utah.

There are 2 varieties for Chorizanthe brevicornu:
Chorizanthe brevicornu var. brevicornu, Brittle Spineflower (AZ, CA, NM, NV, UT);
Chorizanthe brevicornu var. spathulata Brittle Spineflower (CA, ID, OR, NV).

Comments: Blackened plants of Rigid Spineflower may be seen on the desert long after they have thrived and bloomed. In Arizona, the genus Chorizanthe is found in the most desertic parts of the state. The type species for Chorizanthe rigida is from the Williams River, Arizona.

In Southwest Desert Flora also see Rigid Spineflower, Chorizanthe brevicornu.

Date Profile Completed: 06/08/2016, updated format 09/30/2017
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - (accessed 06/02/2016).
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles, California.
Craig C. Freeman, FNA | Family List | FNA Vol.5 | Polygonaceae | Chorizanthe 33. Chorizanthe brevicornu Torrey in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 177. 1859. Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford.
The Plant List (2013). Version 1.1. Published on the Internet; (accessed 06/02/2016).
1993, The Jepson Manual, Citation: (accessed 06/08/2016),5941,5974
SEINet for synonyms, scientific names, recorded geographic locations and general information 06/08/2016).