Stixaceae is a family in the plant order Brassicales

Brassicales

The Brassicales are an order of flowering plants, belonging to the eurosids II group of dicotyledons under the APG II system. One character common to many members of the order is the production of glucosinolate compounds...

. It is no longer recognised by most taxonomists. The three genera formerly included in Stixaceae — Forchhammeria, Stixis and Tirania

Tirania

Tirania purpurea, the sole species in genus Tirania, is a species of climbing plant native to Asia. This genus is related to Forchhammeria and Stixis, but the placement of these three is uncertain. They were placed in Capparaceae until DNA studies showed them to be more closely related to...

— have sometimes been placed instead in the Capparaceae

Capparaceae

Capparaceae , commonly known as the Caper family, is a family of plants in order Brassicales. As currently circumscribed, it contains 33 genera and about 700 species...

, but it is now clear that they do not belong there. It is unknown where they do belong though, so currently they are unplaced at family rank.