The Portulacaceae or purslane family has nearly a worldwide distribution, and although its major diversity is in the southern hemisphere it is also represented in North America and Eurasia. The family contains 20-30 genera and about 500 species of trees, shrubs and herbs, and is currently placed in the same order as the cacti, iceplants, buckwheats, tamarisks, and most carnivorous plants. The leaves are usually simple and entire-margined, often fleshy, glabrous or sometimes with hairs or glandular barbs. The flowers are typically radially symmetrical and are either solitary or in terminal racemes or cymes. The fruit is usually a circumscissile or loculicidal capsule. Many family members are found in arid or semiarid conditions like Portulaca and Calan- drinia. Common purslane (P. oleracea) is a widely eaten but not commercially grown vegetable. Other family members are cultivated as ornamentals.