Yellow corydalis is a familiar 'weed' of gardens, walls and rocky places. It is a garden escapee in the UK, so is not a native plant. Try choosing natives for your garden to prevent…

This sponge is found on rocky shores around the UK and looks like a thick bready crust (if you use your imagination a bit!).

This beautiful bumblebee favours upland areas, but has declined in recent decades and is now nationally scarce.

This glossy wading bird is a scarce visitor to the UK, though records have become more common in recent decades.

As its name suggests, Himalayan balsam is from the Himalayas and was introduced here in 1839. It now an invasive weed of riverbanks and ditches, where it prevents native species from growing.

The rose-red breast, large black cap and thick bill make the bullfinch easy to identify. A plump-looking bird of woodlands, hedgerows and orchards, it also frequents gardens.

As its name suggests, giant hogweed it a large umbellifer with distinctively ridged, hollow stems. An introduced species, it is an invasive weed of riverbanks, where it prevents native species…