General: Arizona Thistle (Cirsium arizonicum) is a two-year or short-lived perennial that spends
the first year as a rosette of spiky leaves. In the second year, it sends up a flower stalk with more spiky leaves and topped with a
spike-protected purplish flowerhead. Unlike most other thistles, the purple flowers of Arizona Thistle tend to stick straight out as
if they were spraying out of the the flowerhead.
Around Las Vegas, Arizona Thistle is an uncommon component of montane vegetation communities in dry, well-drained areas in the Canadian Life (Pine-Fir Forest), Hudsonian (Bristlecone Pine Forest), and Alpine (Alpine Tundra) life zones. Look for this species up on Mt. Charleston and in the Sheep Range.
Compare this species with Whitespine Thistle, which (1) has much longer spines protecting the flowerhead, and (2) lacks wooly hairs on the leaves.