Classified glossary from Vascular Plant Taxonomy by Radford et al. Uniaperturate pollen, apocarpous gynoecium and numerous stamens in a centripetal sequence.
Petals are free.
Some with vesselless wood, laminar stamens and more than two cotyledons. Many have volatile oils. For more information on angiosperm structure see the Encyclopaedia Brittanica for detailed information. More information, in German, from the University of Hamburg with discussions on each of the orders and some illustrations as well as diagnostic characters and information from the University of Lethbridge . In my view, the best rank to express this relationship is that of class.