Oxalis triangularis

Often referred to as the purple shamrock, this beautiful and curious plant actually has nothing to do with Ireland—it comes from Brazil! Oxalis triangularis has stunning triangular, three-lobed leaves—each lobe like a pair of butterfly wings—in vivid purple-maroon and shades of wine-red. In summer, the leaves are accompanied by numerous small, trumpet-shaped pinkish or white blooms. These are attractive in their own right, but it’s the leaves that are the real stars of the show. Incidentally, the foliage has a photonastic response—in other words, the leaves open up during the day and close again at night! Oxalis triangularis subsp. papilionacea may be grown to plant outdoors in summer pots, or a position at the front of the border. It is, however, a frost-tender plant: it might survive outdoors over winter in warm, sheltered gardens, but expect to give it some winter protection. Luckily, it does adapt very well to indoor conditions, and it can survive and indeed thrive, for many years as a long-lived houseplant.