Xylorhiza tortifolia is a species of flowering plant in the family Asteraceae, known by the common names Mojave-aster and Mojave woodyaster. Calflora: Xylorhiza tortifolia The plant forms a small shrub with glandular leaves. The flower rays can be lavender, light blue, or white. Some varieties are known.
Native to southwestern North America, the plant can be found in deserts and washes. The Havasupai found uses for its fragrance.
Description Xylorhiza tortifolia is a perennial herb or subshrub with branching, hairy, glandular stems that reach in height. The leaves are up to long and lance-shaped or narrow, with a spiny tip and spiny-toothed edges, usually with a surface of gray hairs.
At the end of a long peduncle sits the inflorescence, a solitary flower head about across. The head has a base with long, narrow phyllaries which may be over long. The head contains up to 60 or more lavender, pale blue, or white ray florets which may be over 3 cm long. The bloom period is March through June.
The fruit is an achene which may be over 1 cm long, including its pappus of bristles.
Taxonomy Desert species of this aster with a woody base were removed from Machaeranthera, where they were placed for decades.Lady Bird Johnson Wildflower Center Native Plant Information Network−NPIN: Xylorhiza cognata (Mojave aster, Mojave woodyaster) A similar species, X. wrightii (Big Bend aster), is native to the Chihuahuan Desert in western Texas and northern Mexico.
Varieties Xylorhiza tortifolia var. imberbis – Imberis woodyaster, Great Basin region in Nevada, Utah, Arizona.USDA: Xylorhiza tortifolia var. imberbis Xylorhiza tortifolia var. parashantensis – Parashant woodyaster, endemic to Arizona.USDA: Xylorhiza tortifolia var. parashantensis Xylorhiza tortifolia var. tortifolia – Mojave aster, Mojave woodyaster, a variety primarily native to the higher/winter colder Mojave Desert, and Owens Valley of the Great Basin region, from in elevation.Calflora: Xylorhiza tortifolia var. tortifoliaJepson eFlora: Xylorhiza tortifolia var. tortifolia
Etymology Xylorhiza means 'woody base'.
Distribution and habitat
The flowering plant is native to the Mojave Desert, Sonoran Desert, and Great Basin Desert ecoregions of the southwestern United States, California, and northwestern Mexico.Flora of North America − Xylorhiza tortifolia
It grows in arid canyons and bajadas/washes, from in elevation. Habitats it is found in include creosote bush scrub, saltbush scrub, and Joshua tree woodlands.
Uses The Havasupai used the plant for incense and fragrance, with ground leaves carried in the clothes and used as perfume by men and women to counteract body odors.Native American Ethnobotany Database: Xylorhiza tortifolia var. tortifolia
References
Bibliography
External links
Calflora Database: Xylorhiza tortifolia (Mojave woodyaster) USDA Plants Profile for Xylorhiza tortifolia (Mojave woodyaster) Jepson Manual eFlora (TJM2) treatment of Xylorhiza tortifolia var. tortifolia UC Photos gallery for Xylorhiza tortifolia