The black-headed gull is actually a chocolate-brown headed gull! And for much of the year, it's head even turns white. Look out for it in large, noisy flocks on a variety of habitats.

Large scale drainage in the UK has seen a massive reduction in the range of this sensitive aquatic plant which now only occurs in around 50 sites in England.

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 out for the small, yellow flowers of Celery-leaved buttercup in wet meadows and at the edges of ponds and ditches. It flowers from May to September.

The white-letter hairstreak gets its name from the white lines that form a 'W' shape on its underside. It is an elusive butterfly, spending much of its time in the treetops.

Cross-leaved heath is a type of heather that likes bogs, heathland and moorland. It has distinctive pink, bell-shaped flowers that attract all kinds of nectar-loving insects.

A scarce tree of central and southern England, in particular, the small-leaved lime can be found in ancient woodland. It is has sweet-smelling flowers in summer and nut-like fruits in autumn.