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Erigeron rhizomatus
(Zuni fleabane)
[taxon report][distribution map][photos][line drawing]
Family: Asteraceae
Scientific Name: Erigeron rhizomatus Cronquist
Synonyms: None
Vernacular Name: Zuni fleabane
R-E-D Code: 2-2-3
Description: Herbaceous perennial with creeping rhizomes; stems 2.5-4.5 dm tall, sparsely branching from near the base, growing in clumps to about 3 dm in diameter; leaves alternate, oblong, about 1.0 cm long, glabrous except for occasional ciliate hairs on the margins; flower heads solitary terminating the branches, 13-16 mm wide, involucral bracts in several series; ray flowers 25-45, white or tinged with blue-violet, 6-7 mm long and 1.3-1.5 mm wide; disk flowers yellow; achenes 5-6 nerved, nearly glabrous, pappus 25-35 fragile bristles with a few short outer setae. Flowers May and June.
Similar Species: This is a very distinct species of Erigeron. The nearly glabrous achenes with 5-6 nerves, the rhizomatous habit, and the few hairs on the stems and leaves provide easy recognition.
Distribution: New Mexico, Catron, McKinley, and San Juan counties; Arizona, Apache County.
Habitat: Nearly barren detrital clay hillsides with soils derived from shales of the Chinle or Baca formations (often seleniferous); most often on north or east-facing slopes in open piņon-juniper woodlands at 2,200-2,400 m (7,300-8,000 ft).
Remarks: This plant is know from 3 locations in the Zuni Mountains near Fort Wingate, 28 locations (probably more) in the Sawtooth and northwest Datil mountains, and at least 3 locations in the Chuska Mountains on the Navajo Nation.
Conservation Considerations: The distribution of Erigeron rhizomatus is associated with the distribution of uranium deposits in west-central New Mexico. Many of the sites for this plant occur at historical or current mining claims that are uneconomical at present uranium prices. This could change with a greater demand for uranium. Livestock usually do not graze this species.
Important Literature (*Illustration):
Cronquist, A. 1947. A revision of the North American species of Erigeron north of Mexico. Brittonia 6:121-300.
*New Mexico Native Plants Protection Advisory Committee. 1984. A handbook of rare and endemic plants of New Mexico. University of New Mexico Press, Albuquerque.
*U.S. Fish and Wildlife Service. 1988. Zuni fleabane (Erigeron rhizomatus) recovery plan. U.S. Fish and Wildlife Service, New Mexico Ecological Services Field Office, Albuquerque, New Mexico.
Information Compiled By: Charlie McDonald, 1999; last updated 2006
Agency Status:
