This small, white heron is an increasingly common sight in parts of the UK as it spreads north from continental Europe.

An easily overlooked orchid, the Common twayblade is yellow-green and less showy than other UK orchids. Look for it in woodlands and grasslands on chalky soils, in particular.

Look for the wood warbler singing from the canopy of oak woodlands in the north and west of the UK. Green above, it has a distinctive, bright yellow throat and eyestripe.

The Arctic tern is famed for its aggression towards any that would disturb its nest - it will dive-bomb intruders with its sharp beak. Large, noisy colonies can be found on the Farne Islands and…

A common tree, ash is familiar to many of us for its autumnal bunches of winged seeds, called 'keys'. It can be found in woodlands and prefers damp and fertile soils.

The blackbird of the mountains, ring ouzels can be found breeding on upland moors and rocky crags in summer.

A tussocky sedge, Greater pond sedge has stout, upright flower spikes, strap-like leaves and triangular stems. It prefers lowland wetland habitats on heavy soils.

Traditionally a coastal species, Lesser sea-spurrey has spread inland, taking advantage of the winter-salting of our roads. Its pink-and-white flowers bloom in summer.