Fuller's Teasel
The inflorescence is a cylindrical array of lavender flowers which dries to a cone of spine-tipped hard bracts. It may be 10 centimeters long. The dried head persists afterwards, with the small seeds maturing in mid-autumn.
The genus name is derived from the word for thirst, and refers to the cup-like formation made where sessile leaves merge at the stem. Rain water can collect in this receptacle; this may perform the function of preventing sap-sucking insects such as aphids from climbing the stem. An experiment has shown that adding dead insects to these cups increases the seedset of teasels, implying partial carnivory.
"Dipsacus fullonum", syn. "Dipsacus sylvestris", is a species of flowering plant known by the common names Fuller's teasel and wild teasel. 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 and often a noxious weed.
