Systematics
A recent paper has revealed some of the internal structure of the genus Emberiza dividing it into four main clades. Despite morphological divergences the genera Latoucheornis, Miliaria and Melophus were all found to be nested within Emberiza leading the authors to propose their synonymisation with that genus.
Clade A - Emberiza species: tristrami, variabilis, chrysophrys, aureola, pusilla, rutila, rustica, sulphurata, spodocephala, schoeniclus, pallasi, yessoensis, elegans, with "Latoucheornis" siemsseni.
Clade B - Emberiza species: leucocephalos, citrinella, stewarti, cirlus, hortulana, caesia, buchanani, cia, godlewskii, cioides, jankowskii, fucata, with "Miliaria" calandra.
Clade C - Emberiza species: melanocephala, bruniceps with "Melophus" lathami.
Clade D - Emberiza species: striolata, tahapisi, impetuana, capensis, flaviventris, cabanisi.
Buntings not yet tested and therefore still to be placed in this scheme include Emberiza species koslowi & cineracea (probably in clade B), and sahari, socotrana, poliopleura, and affinis (probably in clade D).
Read more about this topic: Bunting (bird)