Thistle
common name of a group of flowering plants / From Wikipedia, the free encyclopedia
Thistle is a group of flowering plants which have sharp prickles on around the flower and are in the Asteraceae family. The prickles often all over the plant – on the stem and flat parts of leaves. This protects the plant against herbivorous animals, stopping them from eating the plant.
The term thistle is sometimes taken to mean exactly those plants in the group Cynareae (synonym: Cardueae),[1] especially the genera Carduus, Cirsium, and Onopordum.[2] However, plants outside this group are sometimes called thistles, and if this is done thistles would form a polyphyletic group.