The other three species differ in the proportion of lower leaves and higher stems that they eat: zebras eat the most stem matter, wildebeests eat the most leaves, and topi are intermediate.

The ancestors of plants were photosynthetic single-celled organisms that gave rise to plants presumably lacked true roots, stems, leaves, and complex reproductive structures such as flowers.

Think of purslane as a great alternative to lettuce: the leaves and stems are crisp, chewy, succulent, and they have a mild lemony taste.