Packera spellenbergii (Spellenberg's groundsel)

Packera spellenbergii (Spellenberg's groundsel)

Photograph by William Dunmire (2000)
Family
ASTERACEAE
Scientific Name with Author
Packera spellenbergii (T.M. Barkley) C. Jeffrey
Synonyms
SENECIO SPELLENBERGII T.M. BARKLEY
Common Name
Spellenberg's groundsel
Rare Plant Conservation Scorecard Summary
Overall Conservation Status Documented Threats Actions Needed
UNDER CONSERVED

Mining and quarrying

Taxonomic studies


County Map
Counties
Description
Diminutive, tufted perennial, 3-5 cm tall, forming clumps up to 2 dm across, covered with white, felty or woolly tomentum; basal leaves linear, 1-2 cm long, 1-2 mm wide, margins rolled inwards; stem leaves reduced to small scales; flower stems taller than basal leaves and terminated by one or two heads; flower heads about 8 mm long, involucral bracts in one series, becoming purplish at maturity; disk flowers yellow, ray flowers absent; achenes short-hairy along the longitudinal angles, pappus of white capillary bristles. Flowers April and early May.
Similar Species
Senecio cliffordii from northwestern New Mexico and south-central Utah approaches Packera spellenbergii in general aspect, but is a larger plant with longer and broader leaves, less tomentum, and has nearly hairless achenes. The ranges of these two species are widely separated.
Distribution
New Mexico, northern Harding and southwestern Union counties.
Habitat
Gravelly balds and mesa rims of chalky, sandy limestone in short grass steppe and juniper savanna; 1,650-1,750 m (5,400-5,800 ft).
Remarks
A very narrowly distributed endemic that is locally abundant on sporadic outcrops of chalky limestone. The total range of Packera spellenbergii is difficult to accurately assess because the large private ranches in this region are sometimes inaccessible to rare plant surveyors. It is named for New Mexico botanist, Richard Spellenberg, who discovered this species.

Senecio cliffordii from northwestern New Mexico and south-central Utah is included as a synonym of this species in Flora of North America, Vol. 20 (2006), which would greatly extend the range of Spellenberg's groundsel. Deb Trock, who authored the Packera treatment in Flora of North America recently visited populations of Senecio cliffordii in New Mexico and now doubts her placement of it as a synonym of Packera spellenbergii (Bob Sivinski pers. comm. 2007). The NMRPTC decided at its meeting on March 30, 2007, to maintain Packera spellenbergii and Senecio cliffordii as distinct species.

Conservation Considerations
The dominant land use of livestock grazing has no direct effect on this unpalatable species. The gravelly limestone balds in this region are occasionally quarried for road base materials. Small ranch road quarries are recolonized by this species, but large county road or state highway projects could remove entire outcrops and eliminate small areas of occupied habitat.
Important Literature

*Barkley, T.M. 1989. New taxa and nomenclatural combinations in Senecio in Mexico and the United States. Phytologia 67(3):237-253.

*Ivey, R.D. 1995. Flowering plants of New Mexico, 3rd edition. Published by the author, Albuquerque, New Mexico.

Jeffrey, C. 1992. The tribe Senecioneae (Compositae) in the Mascarene Islands with an annotated world check-list of the genera of the tribe: Notes on Compositae VI. Kew Bulletin 47(1):49-109.

Flora of North America Editorial Committee. 2006. Flora of North America, volume 20. Oxford University Press, New York.

Information Compiled By
Robert Sivinski 1999; last updated 2007

For distribution maps and more information, visit Natural Heritage New Mexico