Thistle

Thistle is the popular name of a group of flowering plants characterised by leaves with sharp spikes on the margins, mostly in the family Asteraceae. Prickles can also occur all over the plant – on the stem, and on the flat parts of the leaves. These prickles protect the plant from herbivores. Typically, an involucre with a clasping shape, similar to a cup or urn, subtends each of a thistle's flow... (Wikipedia)