This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
One of the most graceful and charming of native plants. It abounds in moist shady woods, rapidly covering the leaf-mould with its fresh yellow-green trefoils and pink-streaked white flowers. In such a situation in April or May it produces beautiful effects. A favourite position for it is the rotten centre of some old beech stump, from which it will spread in a loose cluster, "covering with strange and tender honour the scarred disgrace of ruin," as Ruskin says of the lichens.
The roots are fine and scattered along the creeping knotted pink stems. The leaflets droop close to the stalk at night or on the approach of rain. The flower is regular; sepals five, petals five, stamens ten, stigmas five. The fruit is a five-angled, irritable capsule, from which the seeds are thrown with great force to a distance of several yards. In addition to the coloured spring flowers the Wood-Sorrel produces throughout the summer a large number of buds which never open (cleistogamous), but which develop into seed-vessels and discharge good seeds. The leaves have a pleasant acid flavour, due to the presence of oxalic acid. The generic name refers to this fact, and is derived from the Greek Oxys, sharp.
Oxalis acetosella. - Oxalideae. -