Tetracarpaeaceae

Tetracarpaea
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Core eudicots
Order:	Saxifragales
Family:	Tetracarpaeaceae Nakai
Genus:	Tetracarpaea Hook.
Species:	T. tasmannica
Binomial name
Tetracarpaea tasmannica Hook.

Tetracarpaea is the only genus in the flowering plant family Tetracarpaeaceae. Some taxonomists place it in the family Haloragaceae sensu lato, expanding that family from its traditional circumscription to include Penthorum and Tetracarpaea, and sometimes Aphanopetalum as well.

Tetracarpaea has one species, Tetracarpaea tasmannica, an evergreen, bushy shrub from subalpine areas of Tasmania. It is variable in height, from 1.5 to 10 dm. The leaves are shiny and small, with prominent veins, and the ends of the branches are crowded with small, white flowers. It is not known in cultivation, but has been grown from cuttings.

Tetracarpaea has an odd mix of characters, and during the nineteenth and twentieth centuries, its affinities remained obscure. It was variously classified by different authors, usually with considerable uncertainty.Molecular phylogenetic analysis of DNA sequences has shown that Tetracarpaea is a member of the Haloragaceae alliance, an informal group composed of the families Aphanopetalaceae, Tetracarpaeaceae, Penthoraceae, and Haloragaceae. These are four of the fourteen or fifteen families in the order Saxifragales.

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