Proteales is an order of flowering plants consisting of three (or four) families. The Proteales have been recognized by almost all taxonomists.
The representatives of the Proteales are very different from each other due to their very early divergence. They possess seeds with little or no endosperm. The ovules are often atropic.
Within the classification system of Rolf Dahlgren, the Proteales were in the superorder Proteiflorae, also called Proteanae; The APG II system (of 2003) also recognizes this order, placing it in the clade Eudicots, with the following circumscription:
with "+ ..." = optionally separate family (that may be split off from the preceding family).
The APG III system of 2009 followed this same approach, but favored the narrower circumscription of the three families, firmly recognizing three families in Proteales: Nelumbonaceae, Platanaceae, and Proteaceae.[1] The Angiosperm Phylogeny Website, however, suggests the addition of Sabiaceae, which the APG III system did not place in any order in the eudicots, would be sensible.[5]
Well-known members of the Proteales include the proteas of South Africa, the banksia and macadamia of Australia, the planetree, and the sacred lotus. The origins of the order are clearly ancient, with evidence of diversification in the mid-Cretaceous, roughly over 100 million years ago. Of notable interest is the family's modern distribution; the Proteaceae is predominantly a Southern Hemisphere family, while the Platanaceae and Nelumbonaceae are Northern Hemisphere plants.
Classification
The current APG IV classification represents a slight change from the APG I system of 1998, which firmly did accept family Platanaceae as being separate from the order. Under APG IV, this is the current circumscription of the order:
^ abAngiosperm Phylogeny Group (2009), "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III", Botanical Journal of the Linnean Society, 161 (2): 105–121, doi:10.1111/j.1095-8339.2009.00996.x, hdl:10654/18083
^Magallon, S; Gomez-Acevedo, S; Sanchez-Reyes, LL; Tania Hernandez-Hernandez, T (2015). "A metacalibrated time-tree documents the early rise of flowering plant phylogenetic diversity". New Phytologist. 207: 437–453. doi:10.1111/nph.13264.
^Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 12, July 2012 [and more or less continuously updated since]. Proteales. Accessed online: 9 June 2013.
