The Order Piperales contains two families of flowering tropical herbs, shrubs and small trees many of which are aromatic: Saururaceae with 5 genera and 7 species from N. America and E. Asia, and Piperaceae which includes some succulent species. Some systems of classification add in additional families.
The Piperales are sometimes regarded as paleoherbs, traditionally ranked with the dicotyledons, but with many features characteristic of monocotyledons. As such they may be descended from the very earliest flowering plants. Piperales often have scattered arrangements of vascular bundles in their stems, as seen in monocotyledons and have miniscule flowers without petals, clustered into spikes. The flowers at the botom of the spike may produce a large bract in some species, so that the flower spike appears to rise from a base of petals.
The Piperaceae include the tropical genera Piper and Peperomia which between them contain most of the ca. 1400 species.
Piper species are cultivated for spices, especially P. nigrum (black pepper).
The less succulent Peperomias are commonly raised as houseplants although many have quite succulent stems. The more succulent Peperomias include species with fleshy, windowed leaves and there are a few tuber-forming species.