Main Page | See live article | Alphabetical index Thistle Scientific Classification Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Asterales Family: Asteraceae Genus: Cirsium Thistles are flowering plants of the genus Cirsium. They are known for their effusive flowered heads (usually purple, rose, yellow, or white) and prickly stems and leaves, with a characteristic focal point at the base of the flower which is particularly spiny. Most species are considered weeds, but some are cultivated in gardens for their aesthetic value. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.