Thistles
Pictured to the left is the bloom of what I believe to be California Thistle. It is a common plant in California and the blooms are really quite exquisite, if a bit threatening looking.
John Randolph mentioned that the Purple Thistle to the left is likely a species imported from Eurasia. He may be right. As it turns out there, are two species of Purple Thistle common to California and they are very difficult to differentiate. There is Bull Thistle (Cirsium vulgare ) which is the non-native invasive species and California thistle (Cirsium occidentale var. californicum). Of course, there are a bunch of otherspecies, too.
Since I originally wrote this post, we took a hike at Castle Rock State Park. That link will take you to the state park’s home page. But this (both JPG and PDF links on this page) is the best map I could find (and an incredible map, at that!) Absolutely spectacular hike that is worthy of its own post. While on that hike, we ran across a handful of Red Thistle like the one pictured to the right.
Roger and I found that particular thistle plant while walking on Mt. Eden Trail (it is at the bottom right of this PDF map).
While hiking near Stevens Creek Resevoir (also on the map), we also found several Yellow Star Thistle plants. The flowers make the purple thistle seem almost friendly. Those are some seriously menacing spikes!
Unfortunately, the Yellow Thistle is an invasive species that was imported from Europe.
At this point in the season, California is typically very dry. This season is about average. Hiking is quite interesting because most of the plants have already bloomed and are dead. However, there are many species that have optimized their growth such that they bloom during the dry season. Thistle is one of the larger flowers, but there are a bunch of really really tiny flowers that also show up, too. I’m still trying to figure out how to take a good picture of flowers that are tiny.






July 10th, 2005 at 9:47 am
Ooooh, Star Thistles … I grew up in the foothills of Northern California where the Star Thistles had invaded big-time. Definitely not fun to be around on a daily basis!.
Great photos, though, I must say!
July 11th, 2005 at 8:36 pm
IIRC, that purple thistle is another import. It’s the same one you see in a lot of Scottish heraldry.
The folks in Scotts Valley were a bit nostalgic, it seems. They also brought in Scotch Broom, which is all over the SC mountains now.
-jcr