Thistles can have their own elegance if you let them
They are a weed. Their spiky heads can leave a child wailing and an adult cursing. They are often a blight, an eyesore, something to be dealt with or avoided. They also can have their own beauty and intricacies, if you take the time to look a them in the right light (figuratively and literally).
The proud bloom of a thistle in its prime
When they are fresh, they can be an amazing mix of color.
And sometimes those colors can be surprising
And they are important to our bees, as they flower when little else does.
Hurrah for bees and thistles!
Most of these pictures were taken in the same way- with a long lens and an aperture that was opened up wide. This gives a very tight composition on just the thistle, while blurring out the background for a nice even backdrop. It simplifies the picture, leaves behind extraneous details, and gives the audience only one thing to focus on. Thistles.
A little color is added to the golden fields, for better or worse
I had no idea how excited I would get about this post, until I started it and began remembering about some of the many thistle pictures I have taken and wanted to include.
And finally, winter claims the forgotten thistles of the fall
New
New
Brownie thistle... sometimes even the name can be a little surprising
New
Beauty and pain mixed into simplicity
Galen Leeds Photography 
I especially like your two photographs of the cobwebbed thistles. The webbing is so thorough and so soft that it acts as a great counterbalance to the plant, whose spines manage to assert themselves in spite of their silky covering.
I’ve had a thing for thistles for a decade now, and I featured pictures of the Texas thistle in my blog half a dozen times this year, beginning at
http://portraitsofwildflowers.wordpress.com/2011/07/01/texas-thistle
Like you, I’m fascinated by how scraggly thistles heads become when they dry out and come apart.
Thistles are a very interesting and unjustly disliked plant. Their variety is missed by many who simply lump them all together. The Cobweb Thistles are some of my favorites however, with their stunning contrast of colors