Piperales

Abstract The Piperales are herbs, epiphytes, shrubs, small trees, vines, and lianas, as well as achlorophyllous parasites in one family. Based on molecular and morphological data, the Piperales belong to the basal clade of angiosperms known as the magnoliids, part of the early diversification of flowering plants. The order is scattered across the globe, again attesting to its great age. Traditional medicinal practices use various species of Piperales to treat a variety of ailments, whereas species of Piper have provided spices and hallucinogens since the ancient times and continue to do so. Many species are grown as ornamentals. Species of Aristolochia and Piper produce distinctive secondary compounds associated with feeding by specialised herbivorous insect species. Future studies of Aristolochia , Piper and Peperomia are likely to provide insight into the evolution of hyperdiverse tropical plant families and as a result the great diversity of the angiosperms themselves. Key Concepts: Early diversification of angiosperms took place during the early Cretaceous and occurred in both clades of trees (the Laurales) as well as those including herbs and shrubs (the Piperales). The Piperales consist of five families and 16 genera, some of which contain only 1–2 extant species, whereas in others, species numbers are 100+ ( Asarum and Aristolochia ) and 1000+ ( Peperomia and Piper ). The broad geographic distribution of the Piperales and the diverse growth forms and life styles represented (epiphytes, shrubs, vines, lianas, small trees and parasites) lend further support for a long history of diversification. Many members of this order are of medicinal, cultural and horticultural importance. Interactions between Aristolochia and their pollinators show a high degree of specialisation as do interactions between Aristolochia and Piper and their insect herbivores do. Future studies of the more diverse genera of the Piperales ( Aristolochia , Piper and Peperomia ) are likely to improve our understanding of the processes that have led to the hyperdiversification of certain angiosperm tropical clades and thus diversification of the angiosperms themselves.