Sheep's Sorrel

I had a very pleasant walk round Stanground Wash NR, checking out access for a walk I'm co-leading next weekend. This swathe of Sheep's Sorrel caught my eye. It's a common plant over much of Britain, being a found in many acid grasslands and heathy places, but round Peterborough we have very little in the way of acid soil so it's something of a rarity. Although the individual flowers are tiny, it makes quite an impact when it grows en masse.