Knappy Dread

We were out picking blackberries the other day and came across some Spotted Knapweed (A.K.A. Star Thistle). This is a very controversial plant because it is an important nectar source for honey bees, but it is also an invasive species in parts of the world where it isn't native. Up close, the flowers are actually very pretty.

Unfortunately, the rest of the plant is not particularly attractive.  Here is what it looked like in our blackberry patch.

Usually, however, spotted knapweed is found in large patches where it has eliminated many of its competitors.
Large patches of knapweed can be a very important source of nectar for honey bees and many beekeepers depend on this plant for their livelihoods. The bees use the nectar to make honey (usually sold as Star Thistle Honey) and they can make more honey in less time if the flowers are all growing together in one place.
We saw many insects visiting the knapweed flowers to gather nectar and pollen, like this bumble bee.

In fact, like all flowering plants, spotted knapweed can be an important food source for a variety of insects. It has even been reported as a food plant for the endangered Karner Blue butterfly!
That is not to say that spotted knapweed is not causing ecological damage in areas where it has become invasive. In these areas it is endangering many native plant species that are also important food plants for insects and other animals. It's a very controversial plant and it is likely to stay that way for some time.