This brilliant red and white sea slug would make the perfect nudibranch for a Christmas card image or perhaps a football team mascot!

Water-plantain is an aquatic plant of shallow water and muddy banks. In bloom over summer, it displays tall branches of loosely clustered, pale lilac flowers.

Water-cress has become so popular as a salad addition that it is now cultivated on a wide scale. In the wild, it grows in shallow, fast-flowing streams and is an indicator of clean water.

The Norway spruce was introduced into the UK from Scandinavia in the 16th century. It is familiar to us all as the 'original' Christmas tree and displays hanging, reddish-brown, oblong…

Look for the White water-lily in still and slow-moving water, such as ponds, ditches, lakes and canals. Its lily pads and massive, white flowers float at the water's surface.

Look for the Yellow water-lily in still and slow-moving water, such as ponds, ditches, lakes and canals. Its lily pads and cupped, yellow flowers float at the water's surface.

The brown, oval flower heads of ribwort plantain balance on top of thin, wiry stems; the resulting seed heads provide food for birds in winter. Look for this 'weed' in lawns, fields and…

Like many of our farmland birds, the yellowhammer has declined in number in recent years. Spot this bright yellow bird singing from the top of a bush or fence, or in a mixed-species flock in…