![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Milk_thistle_flowerhead.jpg/640px-Milk_thistle_flowerhead.jpg&w=640&q=50)
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 roots of some thistles help with insulin.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Milk_thistle_flowerhead.jpg/640px-Milk_thistle_flowerhead.jpg)
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.