In 1760 the French zoologist Mathurin Jacques Brisson included a description of the plum-headed parakeet in his Ornithologie based on a specimen collected in India.

[2] Although Brisson coined Latin names, these do not conform to the binomial system and are not recognised by the International Commission on Zoological Nomenclature.

[3] When in 1766 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition he added 240 species that had been previously described by Brisson.

Linnaeus included a terse description, coined the binomial name Psittacus cyanocephalus and cited Brisson's work.

The female has a dull bluish grey head and lacks the black and verdigris collar, which is replaced by yellow.

[10] Some authors have considered the species to have two subspecies, the nominate from peninsular India (type locality restricted to Gingee[11]) and the population from the foothills of the Himalayas as bengalensis on the basis of the colour of the head in the male which is more red and less blue.

[7] The different head colour and the white tip to the tail distinguish this species from the similar blossom-headed parakeet (P. roseata).

They feed on grains, fruits, the fleshy petals of flowers (Salmalia, Butea) and sometimes raid agricultural fields and orchards.

He was author of the lost Indica, a description of India which he wrote based on his experience in Persia and information he gathered from Persian accounts.

[19] Fragments of the Indica were preserved by Photius of Constantinople in his Bibliotheca in the 9th century AD; one of these has been identified as describing Psittacula cyanocephala and its abilities as a talking bird.

[20] It is likely Ctesias saw the bird himself, with an Indian handler; though his description could also apply to Psittacula roseata, that species is native to areas far further east and is much less likely candidate in Greater Iran.