An Ordinal Classification for the Families of Flowering Plants

Recent cladistic analyses are revealing the phylogeny of flowering plants in increasing detail, and there is support for the monophyly of many major groups above the family level.With many elements of the major branching sequence of phylogeny established, a revised suprafamilial classification of flowering plants becomes both feasible and desirable.Here we present a classification of 462 flowering plant families in 40 putatively monophyletic orders and a small number of monophyletic, informal higher groups.The latter are the monocots, commelinoids, eudicots, core eudicots, rosids including eurosids I and II, and asterids including euasterids I and II.Under these informal groups there are also listed a number of families without assignment to order.At the end of the system is an additional list of families of uncertain position for which no firm data exist regarding placement anywhere within the system.Why rearrange families, still less formalize orders?Higher-level classifications, the grouping of species into families, orders, etc., are needed as reference tools not only in systematics but also in many other branches of biology.Knowledge of phylogenetic relationships of major groups of organisms, that is, a phylogenetic perspective, is becoming increasingly important, and hence the need for a phylogenetic classification as a reference tool is also becoming imperative.Our primary focus is on orders with a secondary emphasis on families of flowering plants.The family is central in flowering plant systematics.For example, in studying an unknown plant we usually first identify it to family.The orders, on the other hand, have until quite recently been of little importance, either being morphologically unrecognizable or in most cases lacking any evolutionary coherence (Heywood, 1977;Merxmiiller, 1977).However, orders are useful in teaching, for studying