Xylorhiza tortifolia

Xylorhiza tortifolia
Conservation status
Apparently Secure  (NatureServe)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Asterales
Family:	Asteraceae
Genus:	Xylorhiza
Species:	X. tortifolia
Binomial name
Xylorhiza tortifolia (Torr. & A.Gray) Greene
Synonyms
Aster abatus S.F.Blake Aster mohavensis J.M.Coult. Aster orcuttii Machaeranthera orcuttii

Xylorhiza tortifolia is a species of flowering plant in the family Asteraceae, known by the common names Mojave-aster and Mojave woodyaster.

Distribution

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.

It grows in arid canyons and bajadas/washes, from 240–2,000 metres (790–6,560 ft) in elevation. Habitats it is found in include creosote bush scrub, saltbush scrub, and Joshua tree woodlands.

Description

Xylorhiza tortifolia is a perennial herb or subshrub with branching, hairy, glandular stems that reach 60–80 centimetres (24–31 in) in height/length. The leaves are linear, lance-shaped, or oval, with pointed or spiny tips and spiny edges, while the leaf surfaces are hairy and glandular.

The inflorescence is a solitary flower head borne on a long peduncle. The head has a base with long, narrow phyllaries which may be over 2 centimeters long. The head contains up to 60 or more lavender, pale blue, or white ray florets which may be over 3 centimeters long. The bloom period is March through June.

The fruit is an achene which may be over a centimeter long, including its pappus of bristles.

Varieties

• Xylorhiza tortifolia var. imberbis — Imberis woodyaster, Great Basin region in Nevada, Utah, Arizona.
• Xylorhiza tortifolia var. parashantensis — Parashant woodyaster, endemic to Arizona.
• 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 240–2,000 metres (790–6,560 ft) in elevation.

Taxonomy

Desert species of this aster with a woody base (Xylorhiza means woody base) are classified under the genus Xylorhiza, and have been removed from the large and complex genus Machaeranthera, where they were placed for many decades. A similar species, Xylorhiza wrightii−Big Bend aster, is native to the Chihuahuan Desert in western Texas and northern Mexico.

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.

Bibliography

• Blake, Sidney Fay (1925). Contributions from the United States National Herbarium. Vol. 25. Washington D.C.: Smithsonian Institution Press.
• Coulter, John Merle (1893). Contributions from the United States National Herbarium. Vol. 4. Washington D.C.: Smithsonian Institution Press.

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
• Media related to Xylorhiza tortifolia at Wikimedia Commons