In flower at the moment in Norfolk, the Wood Sorrel, Oxalis acetosella, is a delightful, delicate spring flower. A member of the Oxalidaceae, it has pretty light green trefoli-shaped leaves, composed of three equal and heart-shaped leaflets, which droop at night and in bright sunlight. White flowers with five petals and purple veins are held above the leaves.(There are also deep pink and purple-flowered variants.)

The plant can be found in shady, moist areas throughout the British Isles. It will even grow in conifer plantations, where it can be the only ground flora apart from mosses.

Wood Sorrel has various other names, including Wood-sorrel (note the hyphen), Alleluia (because if appears at Easter), Cuckoo’s bread and cheese and Gowke-Meat (it flowers when cuckoos return here in spring), Wood Sour and Granny’s sour grass.

The last two names refer to the acidity of the leaves, which are delightfully sharp and can be eaten in small quantities. The sourness comes from oxalic acid and it’s best to only eat small quantities, since this is toxic in large amounts – and also because it would be a shame to pick too much of this lovely plant. The Plants For A Future website tells us that the flowers can be added to salads for decoration and that the plant has various medicinal uses. A Modern Herbal tells us that Wood Sorrel was once used as a pot herb, before French Sorrel (Rumex scutatus) was introduced. The specific name acetosella also refers to the sharpness of the leaves – it is shared with equally sharp-flavoured Sheep’s Sorrel, Rumex acetosella.

The Nature Gate website has some more information on Wood Sorrel, plus lovely pictures of the plant (far better than mine), as does the Woodlands.co.uk Blog.