Xylorhiza tortifolia, Mojave Woodyaster, Southwest Desert Flora

Xylorhiza tortifolia, Mojave Woodyaster

Mojave Woodyaster has showy flowers that may be lavender, pale violet, pale blue or whitish. These flowers bloom from March to May and then again in October following sufficient monsoon rainfall. Xylorhiza tortifolia

Mojave Woodyaster green bracts or “phyllaries” subtending an aster flower typically hold key diagnostic characteristics of the species. In this species the “phyllaries” are long and narrow ,and glandular and hairy (note glandular dots and aphid feasting on the viscid secretions’). Xylorhiza tortifolia

Mojave Woodyaster has green leaves up to a maximum of 4 inches long with a soft hairy glandular pubescence and spiny teeth along the leaf margins. Xylorhiza tortifolia

Mojave Woodyaster is a native shrubby plant that grows at elevations between 2,000 and 3,500 feet in Arizona and from 700 to 6,500 feet in California. Photo taken near Bagdad, Arizona. Xylorhiza tortifolia

Scientific Name: Xylorhiza tortifolia
Common Name: Mojave Woodyaster

Also Called: Imberis Woodyaster, Mohave Aster, Mojave Aster, Parashant Woodyaster

Family: Asteraceae, Sunflower Family

Synonyms: (Aster abatus, Haplopappus tortifolius, Machaeranthera tortifolia)

Status: Native

Duration: Perennial

Size: 8 to 24 inches (20-61 cm) or more.

Growth Form: Forb/herb, subshrub; multiple branches from woody base.

Leaves: Green or grayish; several leaves around the base with fewer or no leaves on upper end of stems as shown in the photo above; leaves up to 4 inches (10 cm) long; leaves serrated (prickly - see photo) and broadly lanceolate or broader at the top of the leaf than the bottom (see photo); leaf surfaces with short soft glandular hair.

Flower Color: Lavender, pale lavender, pale violet, blue or whitish-blue solitary flowers; floral heads with both ray and disk florets large showy daisy-like flowers on tips of long stems; bracts surrounding the floral heads broadly linear (see photo).

Flowering Season: March to May and again in October following adequate monsoon rainfall.

Elevation: 2,000 to 3,500 feet (610-1,067 m); 700 to 6,500 feet (213-1,981 m) in California.

Habitat Preferences: Dry rocky slopes, canyons and mesas, ditches, grasslands, oak-pine and pine-woodlands.

Recorded Range: Xylorhiza tortifolia is found in the southwestern United States in AZ, CA, NV, UT. Populations well distributed between all 4 states.

North America & US County Distribution Map for Xylorhiza tortifolia.

North America species range map for Mojave Woodyaster, Xylorhiza tortifolia:

Click image for full size map.

U.S. Weed Information: Unknown
Invasive/Noxious Weed Information: Unknown
Threatened/Endangered Information: Unknown

Wetland Indicator: In North America Xylorhiza tortifolia has the following wetland designations:

Arid West, Facultative, occur in wetlands and non-wetlands

Genus Information: In North America there are 8 species and 8 accepted taxa overall for Xylorhiza. Worldwide, The Plant List includes 10 accepted species names and a further 13 scientific names of infraspecific rank for Xylorhiza.

The genus Xylorhiza was published in 1840, by Thomas Nuttall, (1786-1859).

In the Southwestern United States: Arizona, Nevada and Texas each have 1 species of Xylorhiza, California has 3 species, New Mexico has 0 species and Utah has 5 species. Data approximate, subject to revision.

Genus Information: In North America there are 8 species and 14 accepted taxa overall for Xylorhiza. World wide, The Plant List includes 10 accepted species names and includes a further 13 infraspecific rank for the genus.

In the Southwestern United States: Arizona has 1 species of Xylorhiza, California has 3 species, Nevada has 1 species, New Mexico has 0 species, Texas has 1 species, Utah has 5 species. All data is approximate and subject to taxonomic changes.

There are 3 varieties in Xylorhiza tortifolia;
Xylorhiza tortifolia, var. imberbis, Imberis Woodyaster; (AZ, NV, UT),
Xylorhiza tortifolia var. parashantensis, Parashant Woodyaster; (AZ),
Xylorhiza tortifolia var. tortifolia , Mojave Woodyaster; (AZ,CA, NV, UT).

Comments: Xylorhiza tortifolia is a member of Asteraceae family that has moved over the years from one genus to another (Aster, Haplopappus, Machaeranthera, Xylorhiza).

Importance to Wildlife, Birds and Livestock Mojave Woodyaster, Xylorhiza tortifolia has attractive daisy-like flowers, the flowers, their seeds and plants may be visited by hummingbirds and/or small mammals including rodents and granivorous birds in search of food, nectar and protection through cover.

Beneficial Value to Butterflies, Honey Bees and Insects Mojave Woodyaster, Xylorhiza tortifolia has attractive daisy-like flowers, the flowers and their plants may be visited or used by butterflies, moths, flies, honeybees, native bees and other insects in search of nectar, food or shelter and protection.

Etymology: The genus “Xylorhiza” (Xylorhi'za:) from the Greek xylon, "wood," and rhiza, "root," thus meaning "a woody root."

The genus Xylorhiza was published in 1840, by Thomas Nuttall, (1786-1859).

The species epithet “tortifolia” (tortifo'lia:) from the Latin for "twisted leaf."

Ethnobotany Mojave Woodyaster, Xylorhiza tortifolia is used by the Havasupai in the United States.

Havasupai Other, Incense & Fragrance; Ground leaves carried in the clothes and used as perfume by men and women to counteract body odors.

See complete listing of ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.