The Sessile oak is so-called because its acorns are not held on stalks like those of the familiar English oak. It can be found in woodlands mainly in the north and west of the UK.

Small-spotted catsharks used to be called lesser-spotted dogfish - which might be what you know them best as. It's the same shark, just a different name!

The tightly packed, thistle-like purple flower heads of common knapweed bloom on all kinds of grasslands. Also regularly called black knapweed, this plant attracts clouds of butterflies.

The smaller of our two UK seal species, common seals are also known as harbour seals. Despite being called "Common", they are actually less common than grey seals!

Heather is also called 'ling'. Look for it on our heaths, moors and bogs, where its delicate, loosely arranged pink flowers attract all kinds of nectar-loving insects.

Famously predatory, the long, slender pike will lurk among the vegetation of a river or lake, bursting out with ferocious speed to catch its prey. Look out for it across the UK.