Proteales is the name given to an order of plants within the angiosperms. Modern classifications based on molecular evidence place this group among the eudicots of the flowering plants. Although the circumscription has varied over time, contemporary treatments generally recognize a small set of families that are distinctive in form and ecology.

Families commonly included

Current systems usually include three well established families:

  • Proteaceae – a largely woody family best known from the Southern Hemisphere (genera such as Protea, Banksia and Grevillea).
  • Nelumbonaceae – the lotus family, represented by the aquatic genus Nelumbo.
  • Platanaceae – the plane-tree family, with the single widely recognized genus Platanus.

Taxonomic history

The membership and rank of Proteales have changed between classification schemes. Morphology-based systems sometimes grouped different sets of families together, while molecular phylogenetic studies over the past few decades have led to a more stable circumscription that unites the families listed above. The order is now commonly accepted by most plant taxonomists and appears in major modern classification systems.

Evolution and fossil record

Fossils attributable to members of Proteales or their relatives are known from the Cretaceous and later periods, indicating an ancient origin. The distribution of living Proteaceae and related lineages reflects a long evolutionary history that includes diversification on southern landmasses after the breakup of Gondwana.

Morphology, ecology and uses

Members of the order display a wide range of growth forms and ecologies: Proteaceae are often shrubs or trees adapted to nutrient-poor soils (many produce specialised cluster roots), Nelumbo are aquatic plants with distinctive floating leaves and showy flowers, and Platanaceae are large temperate trees frequently planted in urban landscapes. Several species are cultivated for ornamental, cultural, or ecological purposes.

Further notes

Because Proteales unites groups that can look quite different from one another, diagnostic characters apply more readily to individual families than to the order as a whole. Molecular data remain the primary basis for placing these families together and for resolving relationships among them.