[taxon report][distribution map][all photos][line drawing]
Scientific Name: Cirsium gilense Wooton and Standley
Vernacular Name: Gila thistle
R-E-D Code: 1-1-3
Description: Biennial; stems up to 2 m tall, sparingly branched, hairy; leaves about 40 cm long, pointed at the tip, lobed, the lobes toothed, teeth tipped with slender spines, upper surface of the leaves hairy, lower surface without hairs; the base of the stem leaves partly surrounding the stem; flower heads greenish-yellow usually solitary at the ends of the branches, about 3 cm broad, and nearly as high; outer bracts of the flower head with cobwebby hairs and numerous small, spiny teeth of even length along the margins, much like that of a comb. Flowers July to September.
Similar Species: Cirsium gilense can be differentiated from any other yellow-flowered thistles in New Mexico by flowering heads that are at least 3 cm high and are solitary at the ends of branches. The bracts of the heads have broad green tips.
Distribution: New Mexico, Catron County; adjacent Arizona, White Mountains.
Habitat: Moist areas or mountain meadows in montane coniferous forest; 2,135-2,440 m (7,000-8,000 ft).
Remarks: This taxon, along with all other yellow-flowered thistles of the Southwest, needs further study to clarify species boundaries.
Conservation Considerations: All native thistles could potentially be impacted by exotic biological control agents imported to combat noxious exotic thistles.
Important Literature (*Illustration):
*New Mexico Native Plants Protection Advisory Committee. 1984. A handbook of rare and endemic plants of New Mexico. University of New Mexico Press, Albuquerque.
Wooton, E.O. and P.C. Standley. 1913. Descriptions of new plants preliminary to a report upon the flora of New Mexico. Contributions from the U.S. National Herbarium 16:109-196.
Roth, D. 2016. Wildfire Impacts on Species of Concern Plants in the Gila National Forest, New Mexico. Unpublished report prepared by EMNRD-Forestry Division, Santa Fe, NM for the U.S. Fish & Wildlife Service, Region 2, Albuquerque, NM. 48 pp.
Information Compiled By:
Patricia Barlow-Irick, 1999; updated 2016