''Tirania purpurea'', the sole species in genus ''Tirania'', is a species of climbing plant native to

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

. This genus is related to ''

Forchhammeria ''Forchhammeria'' is a genus of plants in the order Brassicales. This genus has previously been placed in the Stixaceae (now obsolete) and Capparaceae, but under the APG IV system is now included in the family Resedaceae. Species can be found ...

'' and '' Stixis'', but the placement of these three is uncertain. They were placed in

Capparaceae The Capparaceae (or Capparidaceae), commonly known as the caper family, are a family of plants in the order Brassicales. As currently circumscribed, the family contains 33 genera and about 700 species. The largest genera are ''Capparis'' (about ...

until DNA studies showed them to be more closely related to

Resedaceae Resedaceae is a family of mostly herbaceous dicotyledonous plants comprising 107 known species in 8 to 12 genera: *''Borthwickia'' - 1 species, sometimes placed in its own family Borthwickiaceae *''Caylusea'' - 3 species *''Forchhammeria'' - 10 s ...

that to Capparaceae. They are sometimes placed in their own family Stixaceae, but since it is not yet clear whether they are from a clade, they are better left in

Brassicales The Brassicales (or Cruciales) 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 (mustard oil) compo ...

unplaced at family rank.

References

Flora of Asia Monotypic Brassicales genera Resedaceae {{Brassicales-stub