©The World Botanical Associates Web Page
Prepared by Richard W. Spjut
December 2004, Dec. 2005, Feb 2013

Xylorhiza glabriuscula
S Wyoming;
June 2005

Xylorhiza tortifolia
Chuckwalla Mts., CA;
Spjut 3374, May 1973


Xylorhiza tortifolia
Kern Co.: Jawbone Canyon., CA;
20 April 2011


Xylorhiza tortifolia
Mojave Desert, Kern Co., CA
Spjut, 15194, Apr 2003


Xylorhiza tortifolia
Inyo Co., CA; May 1973


Trees and Shrubs of Kern County (Sep 2012)

Xylorhiza tortifolia (Aplopappus tortifolia Torrey & A. Gray 1845) Greene 1896 [Machaeranthera tortifolia Cronquist & Keck 1957] var. tortifolia. Desert aster. Subshrub with a low widely branched woody base and erect leafless flowering stems; leaves mainly on seasonal relatively short herbaceous branches at the base of the longer flower scapes, alternate, strap-like and twisted, the margins wavy with triangular to spine-like teeth, or teeth lacking, 2–7 cm long, 3–18 mm wide, with plain and glandular tipped hairs; flowering Mar–Oct; flowers with 4–14 lavender or pale purplish rays and many yellow disc florets, the heads solitary and terminal on long leafless flower stems 10–18 cm long; involucral bracts numerous in 4–5 graduated series, sword-shaped; cypselae with a 4-nerved cylindrical pericarpium and terminal silky bristles. Rocky slopes in creosote, shadscale, and sagebrush deserts below 6,500 ft, California to Utah and Arizona.  Type from California. Kern Co.: Mostly desert regions, canyons from Owens Peak to Harper Lake, Kramer Junction, Rosamond, Piute Mt., Red Rock and Jawbone, 731–2,028 m (CCH).  One other variety: var. imberbis (Cronquist) T.J.. Watson, occurs in southern Nevada, Utah and Arizona; it differs in having less hairs.