Dilleniaceae

A family displaying greater variability than usual, and thus difficult to define in a few short sentences. Since the family is represented in FZ by just one genus the description of the genus should suffice.

Comment: Placing the family has proved difficult. A major objective of the first meeting of the Angiosperm Phylogeny Group (1998) was to reduce to number of Eudicot orders to around 40, largely to facilitate filing of herbarium material. Orders comprising just one or two families should be merged with larger orders. In the case of Dilleniaceae this meant placing the family in the Caryophyllales, a somewhat awkward fit. In such cases the practice of bracketing was allowed: Order Caryophyllales (Dilleniales), but described as “unplaced”. In subsequent meetings of APG the placement of the family has remained unresolved. Dilleniaceae is one of the oldest of the Eudicots, having emerged in the mid-Cretaceous about 115 million years ago, although the “crown group” diverged much later, 52 million years ago (Wikipedia). As such it links the Eudicots with the more primitive Dicots. Eudicots – Order Caryophyllales (Dilleniales) – Family Dilleniaceae.

Worldwide: C. 12 genera and 300 species, tropical and subtropical, especially Australasia.

Zambia: 1 genus and 2 taxa.