The distinctive silhouette of teasel (Dipsacus sativus) is a familiar sight in the coastal parts of California. Thick, pointed bracts jut out, like splayed arms beneath the cone-shaped flower head. This structure stays standing long after the small white flowers have faded; people collect the dried stems for decoration. The spiny flower heads are so stiff they were used to card wool before metal carding combs were created!
Sadly this odd-looking plant is also a fairly nasty invasive. It can form dense chest-high thickets that are impassable to both people and animals. This European invasive likes to grow in disturbed areas: along roadways, in ditches and on grasslands. Another species, wild teasel (Dipsacus fullonum) is less common locally but more widespread throughout North America. It has pink-to-purple flowers and sharply upcurved bracts. Just to confuse things, both species also go by the common name of Fuller’s teasel.