Published in Rhodora, Volume 79, Issue 1, January 1, 1978, pages 32-78.
NOTE: At the time of publication, the author David J. Keil was not yet affiliated with Cal Poly.
Pectis L. sect. Pectothrix A. Gray (Compositae: Tageteae) comprises a group of showy, yellow-headed species which occurs mainly in the arid and semi-arid portions of the southwestern United States and northern Mexico. Although several regional floras have included one or more of the species in this group, no workers since Fernald (1897) and Rydberg (1916) have attempted to treat this portion of genus in its entirety. Since 1916, several workers have described new taxa (Cory, 1927; Johnston, 1940; Wiggins, 1951; Keil, 1974), and many new collections have been made. Recent studies (Keil, 1974) have suggested that the species relationships proposed by earlier workers (Fernald, 1897; Gray, 1884; Rydberg, 1916) should be re-examined.
The definitive version is available at Botanicus.org.