[Cal-IPC] Ecological impact: Dipsacus fullonum (common teasel) is a biennial forb/herb (family Dipsacaceae) sometimes used in flower arrangements, but was historically used as a hairbrush. It becomes a problem when it forms dense stands that are impenetrable to humans or livestock. (contributed by Mary Ann Machi)

[Wikipedia] Eurasia & North Africa native: Dipsacus fullonum, syn. Dipsacus sylvestris, is a species of flowering plant known by the common names wild teasel or fuller's teasel, although the latter name is usually applied to the cultivated variety D. fullonum var. sativus.[2] It is native to Eurasia and North Africa, but it is known in the Americas, southern Africa, Australia and New Zealand as an introduced species. (contributed by Mary Ann Machi)