citron: thorny evergreen small tree or shrub of India widely cultivated for its large lemonlike fruits that have thick warty rind
citrus: any of numerous tropical usually thorny evergreen trees of the genus Citrus having leathery evergreen leaves and widely cultivated for their juicy edible fruits having leathery aromatic rinds
genus pitta: type genus of the Pittidae; a large genus of birds of southern Asia and Australia and adjacent islands