Sorrel

Procumbent Yellow-sorrel (Oxalis corniculata)

We currently have a whole community of small, creeping plants thriving on the gritty soil of our driveway. This one is the Procumbent Yellow-sorrel, also known as Creeping Woodsorrel. It's another clover relative, like the Lesser Trefoil I introduced you to a few weeks ago. Its sunny, yellow flowers rise a mere inch or two off the ground, and its maroony-purple, trefoil-shaped leaves paint splashes of colour all along the edge of the drive. Rumour has it that the leaves are sometimes green, but all of ours are the rich colour seen in the picture above. The whole plant forms a little mat up to 15 cm (6 in) or so in diameter, with a small number of five-petalled flowers rising from each mat. This little annual (sometimes a short-lived perennial) prefers dry, open places, so our unimproved drive suits it perfectly. Introduced into the UK in the mid-1600s from the Mediterranean region, it's now fairly common across England and Wales, less so in Scotland. It's still often found around human habitation, but has also escaped into the wider countryside, where it has now naturalised.

Intriguingly, it seems that the plant may actually be native to southeast Asia, brought to Italy (intentionally or not) by traders. It is now found across much of the world, even on sub-Antarctic islands! Packed with vitamin C, it has been widely used for culinary and medicinal reasons. Its leaves are said to taste of lemons, and various parts of the plant have been used to treat everything from diarrhoea and wounds to scurvy, hookworms and arsenic poisoning. It has known antibacterial properties. It's a known hyperaccumulator of copper, and can be used to remediate contaminated soils. It's often considered to be an invasive weed in garden centre stock and urban gardens, spreading itself around by explosively flinging its seeds in all directions. Fortunately for the pollinators, which appear to greatly appreciate it, we don't care where it crops up.