[Cal-IPC] Invasiveness: Dipsacus sativus (Fuller?s teasel) is a biennial (family Dipsacaceae) found in California?s Coastal and Peninsular Ranges and the San Francisco Bay area. It favors disturbed sites, including grasslands, roadsides, ditches and riparian sites. Fuller?s teasel?s spiny flower heads were used for carding wool before metal carding combs were created. Teasel plants may grow to form dense stands that are impenetrable by humans and animals. Teasel seeds can survive in the soil for 6 years or more, and once a dense population is established, it can persist for decades. Small populations may be mechanically controlled by removing plants to a few inches below the root crown. (contributed by Mary Ann Machi)

[Wikipedia] Europe, Asia, northern Africa native: Dipsacus is a genus of flowering plant in the family Caprifoliaceae.[1] The members of this genus are known as teasel, teazel or teazle. The genus includes about 15 species of tall herbaceous biennial plants (rarely short-lived perennial plants) growing to 1 to 2.5 metres (3.3 to 8.2 ft) tall. Dipsacus species are native to Europe, Asia and northern Africa. (contributed by Mary Ann Machi)