Many spring flowers are very colourful and beautiful like violets, primroses, cowslips, celandines and the rest. But this little plant, called Dog's Mercury, is so small and insignificant that you have to get up close to appreciate its modest beauty.
Because most of the flowers are male flowers it rarely produces seed. Instead it spreads by underground runners called rhizomes. This takes quite a while. And it can't really compete with grass in a field. So if you see a large area of Dog's Mercury it is likely to be in a hedgerow or a wood, and it is likely that that hedgerow or wood has been there a very long time. We call plants like this 'Ancient Woodland Indicators'.