The Purple hairstreak is an elusive butterfly with a brilliant purple sheen. It is entirely reliant on oak trees and can be spotted chasing around the treetops in woodlands and parks.

The black hairstreak is a rare butterfly that is restricted to woodlands and hedgerows containing blackthorn - the foodplant of the caterpillar. It is both elusive and hard to tell apart from…

The brown hairstreak is an elusive butterfly that spends much of its time in the treetops feeding on aphid honeydew.

The green hairstreak is the UK's only green butterfly. Look out for the vibrant, metallic sheen of the undersides of its wings on grassland and moorland, and along woodland rides.

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.

The male purple emperor is a stunning butterfly with a brilliant purple sheen. Look for it feeding around the treetops in woodlands, or on damp ground, animal droppings or even carrion in the…

One of our commonest willows, the Goat willow is a small tree that is found in ditches, reedbeds and wet woodland. It is well-known for its silver, fluffy catkins that give it another name, '…

One of our commonest willows, the Grey willow is a small tree that is found in ditches, reedbeds and wet woodland. It is well-known for its silver, fluffy catkins that give it another name, '…

So-named for the silvery-white appearance of its leaves, the White willow can be seen along riverbanks, around lakes and in wet woodlands. Like other willows, it produces catkins in spring.

So-named because its gnarled trunk can split as it grows, the Crack willow can be seen along riverbanks, around lakes and in wet woodlands. Like other willows, it produces catkins in spring.

A summer visitor, the willow warbler can be seen in woodland, parks and gardens across the UK. It arrives here in April and leaves for southern Africa in September.

The small white is a common garden visitor. It is smaller than the similar large white, and has less black on its wingtips.