The 1959 Injurious Weeds Act does not just apply to ragwort. It names four more species as well: broad leaved dock, creeping thistle, curled dock, and the spear thistle. We have them all.
The creeping thistle (Cirsium arvense) is in flower now. Like ragwort, it is a significant late-season source of food for all kinds of invertebrates. Usually, but not always, each creeping thistle plant produces only male or female flowers; the male flowers make large amounts of pollen and the female flowers announce their copious nectaries with perfume.
Beetles and wasps come for the pollen, bees and butterflies for the nectar and several species of Cantharidae come to prey on the pollinators. There are leaf miners and stem borers feeding unseen inside the leaves and stems, and even this late in the summer there are caterpillars feeding on the leaves. On a warm day a drift of creeping thistle buzzes with wildlife.
Later in the season finches and linnets will come for its seeds. It is an important part of the park’s ecology.
Creeping thistle is another of those plants that can reproduce vegetatively and sometimes prefers to do so. It has underground stems that can spread up to ten metres away from the parent plant in one season and produce a new plant at each node. This means that a thistle colony covering several acres might be a clone of a single plant.
Below is a photo gallery of the reserve’s creeping thistles and some of the creatures we have seen feeding on them.
Southwick Country Park Nature Reserve 