High Quality Content by WIKIPEDIA articles! Portulacaceae are a family of flowering plants, comprising about 20 genera with about 500 species, ranging from herbaceous plants to shrubs. The family has been recognised by most taxonomists, and is also known as the purslane family; it has a cosmopolitan distribution, with the highest diversity in semi-arid regions of the Southern Hemisphere in Africa, Australia, and South America, but with a few species also extending north into Arctic regions. The family is very similar to the Caryophyllaceae differing in the calyx which has only two sepals.