Ildefonsia is a monotypic genus of flowering plants belonging to the family Plantaginaceae. The only species is Ildefonsia bibracteata.[1]
It is native to Rio de Janeiro state in southeastern Brazil.
The genus name of Ildefonsia is in honour of Antonio Ildefonso Gomes de Freitas (1794–1859), a Brazilian botanist and doctor in Rio de Janeiro.[2] The Latin specific epithet of bibracteata refers to 'bi' meaning 2 and 'bracteate' meaning possessing bracts which is a modified leaf associated with a flower or inflorescence.Both genus and species were first described and published by George Gardner in 1842.[3]