Mediterranean region, southern Europe, northern Africa, and western Asia
Italian thistle is an upright forb that typically grows as a winter annual but occasionally grows as a biennial. Plants grow to 4 ft (1.2 m) tall on average from stout taproots. Leaves are alternate, lance-shaped, covered with short, matted hairs on the undersides, and have spines on lobe tips. Stems are slender, narrowly winged, and spiny. Flower heads appear in tight clusters at branch tips. Flower head bracts are long and triangular with cobwebby hairs at their base. Florets are pinkish-purple. There are two types of seeds: cream-colored with tufts of fine hair and brown-colored without.
Introduced thistles currently infest millions of acres across North America, primarily occurring in or along roadways, waterways, agricultural fields, rangelands, pastures, forests, and disturbed areas. They are responsible for millions of dollars of damage annually in reduced agricultural yields and lowered forage value in grazing systems. Introduced invasive thistles can also displace native vegetation, negatively impacting wildlife and threatening the delicate ecological balance within many habitats.
Randall, C.B., J.E. Andreas, and J. Milan. 2024. Introduced Thistles: History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2024-8- INTRODUCED THISTLES-P. https://bugwoodcloud.org/resource/files/29168.pdf