Ground-elder was likely introduced into the UK by the Romans and has since become naturalised. A medium-sized umbellifer, it is an invasive weed of shady places, gardens and roadsides.

Look for Water avens in damp habitats, such as riversides, wet woodlands and wet meadows. It has nodding, purple-and-orange flowers that hang on delicate, purple stems.

Look for wood avens along hedgerows and in woodlands. Its yellow flowers appear in spring and provide nectar for insects; later, they turn to red, hooked seedheads that can easily stick to a…

This slim fish is usually found on gravelly parts of the seabed, close to shore, but can turn up in rockpools.