Wood sorrel. That is right. Not oxalis but wood sorrel. Oh all right, they are the same but the poor oxalis gets a really bad rap because of a few bad eggs in the family. We wouldn’t be without the ornamental oxalis in pots and in the rockery. The autumn and winter flowering varieties add a bright spot of colour, though they need sun to open their flowers.
There are around 500 different oxalis so our collection of about 30 is merely scratching the surface. As a general rule, the South African species are dormant in summer and the autumn rains trigger them into growth and flower whereas the South American species follow the opposite seasons. But that is not a hard and fast rule and some oxalis are evergreen succulents and not bulbs at all. By no means all of the oxalis are invasive but if you are not sure, keep them to pots and watch them for a while. If they have tiny bulbs which increase exponentially or if they have bulbs which reach out below the ground with small bulblets attached, then be wary.
While my personal favourite is purpurea alba (large pure white flowers with a golden eye, long flowering season and completely non invasive, in our experience), flava pink in the photo is a real charmer. Large flowers in pretty pink and interesting foliage which resembles miniature palm leaves.