Common thistle

Did you know that thistles are in the same family as daisies? I found that unbelievable at first: the cheerful white and yellow daisies which dot sunny meadows cousin to the thorny thistles which brood in dark open spaces under trees? But then I considered the evidence. Like their other cousins, the asters and sunflowers, both are complex flowers. There are the colourful petals surrounding a distinct center. When you look at the center, you find them full of complete tiny flowers called the disk florets. The circle of “petals” around this disk are each a flower, a ray floret, which has given up its identity by fusing into a larger structure. There are other commonalities, but this observation began to break down my initial disbelief.

I’ve usually seen them under dense growths of pines or deodar (cedar) which dot Himalayan grasslands, in places where the sunlight does not reach easily and other flowers shun. I suppose these are its refugia, safe places, where humans don’t hunt them down. They do not actively shun sunlight, because they can grow also in farmlands, but they are usually evicted quite quickly from there. Maybe they need some open space around the base, which is why they do not grow where the grass is dense. I’ll have to look more carefully at its base in future.

But was this particular plant a common thistle (Cirsium verutum) or Wallich’s thistle (Cirsium wallichi)? The flower head is not sufficient to clearly distinguish the two. I had to look at the leaves and the stem. The common thistle has leaves which end in a long spine, with other spines along the lobes on the sides. Wallich’s thistle has a less pronounced terminal spike and a hairy stem. So I think this was Cirsium verutum, the common thistle.