This is the oxalis which is commonly sold around St. Patrick's Day as shamrocks. It's not native to Ireland but rather to Brazil. Big pots thickly filled with foliage of these easily grown plants are very ornamental. I'm apt to regard the flowers as a distraction and pull them off.
There are several Central American species of Oxalis which are readily and inexpensively available and also make very decorative pots. Look for Oxalis lasiandra and the forms of O. deppei.
All of these can be stored as dry bulbs/rhizomes during the winter if there is no room to grow them as house plants.