Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Sonchus asper, Spiny Sowthistle

Sonchus asper, Spiny Sowthistle, Southwest Desert Flora Sonchus asper, Spiny Sowthistle, Southwest Desert Flora Sonchus asper, Spiny Sowthistle, Southwest Desert Flora   Sonchus asper, Spiny Sowthistle, Southwest Desert Flora

Scientific Name: Sonchus asper
Common Name: Spiny Sowthistle
Also Called: Perennial Sowthistle, Prickly Sow Thistle, Prickly Sow-thistle, Prickly Sowthistle, Sharp-fringed-Sowthistle, Sow-thistle, Spiny Sow-thistle, Spiny-leaf Sow Thistle (Spanish: Chinita, Cerraja, Hoiidkam iwaki)
Family: Asteraceae, Sunflower Family
Synonyms: (Sonchus nymanii)
Status: Introduced
Duration: Annual, taproot
Size: Up to 5 feet.
Growth Form: Forb/herb; erect, tall, basal leaves; branching above; stems mostly hairless (glabrous) emit milky sap when broken.
Leaves: Green or glaucous; shiny, 2 to 10 inches, hairless; alternate; basal rosettes, pinnately or deeply cut with lateral appendages; clasping lobes with soft spines on tips, blades recurved, sessile, margins also prickly.
Flower Color: Pale yellow; ray strap-shaped (ligulate) flowers only; heads small ½ to 1 inch, in clusters on open branches; flowering stalks (peduncle) bristly; fruit an achene in rounded white feathery heads; dandelion-like, wind driven seed dispersal.
Flowering Season: February to August or may bloom year around.
Elevation: Sea Level to 8,000 feet.

Habitat Preferences: Common, slightly moist areas, roadsides, disturbed areas and waste areas, cultivated areas, gardens.

Recorded Range: Throughout most of North America, northern Baja California and northern, central and southern Mexico. Throughout most of Arizona.

North America & US County Distribution Map for Sonchus asper.

U.S. Weed Information: Sonchus asper is listed in: Weeds of Kentucky and adjacent states: a field guide, Weeds of Nebraska and the Great Plains, Weeds of the United States and Canada, and Weeds of the West. Plants included here may become weedy or invasive.

Invasive/Noxious Weed Information: No data available.

Wetland Indicator: Sonchus asper is listed on the USDA 2012 National Wetland Plant List.

Threatened/Endangered Information: No data available.

Genus Information: 5 species in Sonchus, all invasive, 2 species in Arizona.

Comments: An introduced European invasive naturalized throughout North America and Greenland. The basal rosette may be confused with thistles which do not have milky sap. Other plants with similar appearances include; Annual Sowthistle, Sonchus oleraceus which has pointed lobes that clasp the stem and is generally less prickly and Prickly Lettuce, Lactuca serriola which differs with spines on the midvein under the leaf.

In Southwest Desert Flora also see Prickly Lettuce, Lactuca serriola.

Native Americans cooked the tender leaves as greens, see species account from Native American Ethnobotany, University of Michigan, Dearborn.

Date Profile Completed: 8/4/2012; Updated, 07/26/2015, updated format 10/11/2017
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles
The Jepson Manual, Citation: Sat Aug 4 08:05:46 2012
Philip E. Hyatt, FNA | Family List | FNA Vol. 19, 20 and 21 | Asteraceae | Sonchus, Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford. (accessed 08/04/2012)
Virginia Tech Weed Identification Guide, Spiny Sowthistle: Sonchus asper, (Scott Hagood) 08/04/2012
SEINet for synonyms, scientific names and recorded geographic locations,