Size: 12 to 24 inches (30-61 cm) or more; 3 feet (91 cm)
Growth Form:Forb/herb; plants upright (erect) and spiny; milky sap visible if stems or leaves broken or cut; stems typically without surface ornamentation such as hairs, scales or bristles.
Leaves: Green leaves with variable shapes and sizes; leafy on the upper part of stem, leaves arranged alternately on stems; leaves prickly and clasping the stems as shown in photo above; leaves with small teeth and deeply cut lobes
Recorded Range: Throughout the United States and Canada. Also native to Baja California and northwest Mexico. In the southwestern part of the United States, Prickly Lettuce occurs in largest populations in AZ, CA, NM, NV and UT.
North America species range map for Prickly Lettuce Lactuca serriola:
North American range map courtesy of Virginia Tech, Dept. of Forest Resources & Environmental Conservation
Click image for full size map
U.S. Weed Information: In North America Lactuca serriola can be weedy or invasive according to the following authoritative sources:
Weeds of Kentucky and adjacent states: a field guide,
Weeds of the Northeast,
Weeds of Nebraska and the Great Plains,
Weeds of the United States and Canada,
Weeds of the West.
Plants included here may become weedy or invasive.
Wetland Indicator: In North America Lactuca serriola has the following wetland designations:
Arid West, FACU
Atlantic and Gulf Coastal Plain, FAC;
Eastern Mountains and Piedmont, FAC;
Great Plains, FAC;
Northcentral & Northeast, FACU;
Western Mountains, Valleys, and Coast, FACU;
FAC = Facultative, occur in wetlands and non-wetlands
FACU = Facultative Upland, usually occur in non-wetlands, but may occur in wetlands
Genus Information:12 species in Lactuca throughout North America including Canada and Alaska. 5 species in various habitats in Arizona.
Genus Information: In North America there are 13 species and 13 accepted taxa overall for Lactuca. Worldwide, The Plant List includes 147 accepted species names and a further 213 scientific names of infraspecific rank for the genus.
In the Southwestern United States: Arizona has 5 species of Lactuca, California has 8 species, Nevada has 3 species, New Mexico has 8 species, Texas has 8 species, Utah has 5 species. Data approximate and subject to revision.
Comments:Lactuca serriola is a naturalized weedy plant native to Europe that can be found in Arizona most anywhere in suitable habitat. It is similar, at least superficially so, to the Common Sowthistle, Sonchus oleraceus and to Spiny Sowthistle, Sonchus asper.
Importance to Wildlife, Birds and Livestock
Although Prickly Lettuce, Lactuca serriola is an introduced species, flowers, seeds and plants may be visited by hummingbirds and/or small mammals including rodents in search of food.
Beneficial Value to Butterflies, Bees and Insects
Although Prickly Lettuce, Lactuca serriola is an introduced species, its brightly colored flowers and plants may be visited by butterflies, moths and other insects in search of food and nectar.
The genus “Lactuca” (Lactu'ca:) a reference to (lac'ta:) which is Latin for “milk,” referring to the milky sap in stem, and a root word for lactic acid.