Thistle

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 roots of some thistles help with insulin.

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.

Thistle is the floral emblem of Scotland.

1. ↑ "Cardueae ("thistles")". BioImages: The Virtual Field-Guide (UK). Archived from the original on 2007-10-09. Retrieved 2007-11-30.
2. ↑ "thistle". Merriam-Webster's online dictionary. Retrieved 2007-11-30.