Rosella - Taxonomy

Taxonomy

The genus was described by naturalist Nicholas Aylward Vigors in 1825; the name Platycercus derived from the Ancient Greek "broad-" or "flat-tailed". The relationships with other parrots have been unclear, with the Australian Ringneck cited as a closest relative by some, and the genus Psephotus by others; the plumage of the Western Rosella seen as a link to the latter genus.

There are, broadly speaking, three groups of rosella species. They are the blue cheeked species which includes elegans and caledonicus, the white cheeked species, eximius, adscitus and venustus and the yellow cheeked species, icterotis. The observed difference in plumage has been reinforced by molecular studies which place the icterotis as a basal offshoot.

There are six species and several subspecies:

Platycercus,

Platycercus caledonicus,
- Platycercus caledonicus brownii,
- Platycercus caledonicus caledonicus,
Platycercus elegans,
- Platycercus elegans elegans,
- Platycercus elegans flaveolus,
- Platycercus elegans fleurieuensis,
- Platycercus elegans melanopterus,
- Platycercus elegans nigrescens,
- Platycercus elegans subadelaidae,
Platycercus venustus,
- Platycercus venustus hilli,
- Platycercus venustus venustus,
Platycercus adscitus,
- Platycercus adscitus adscitus,
- Platycercus adscitus palliceps,
Platycercus eximius,
- Platycercus eximius diemenensis,
- Platycercus eximius elecica,
- Platycercus eximius eximius,
Platycercus icterotis,
- Platycercus icterotis icterotis,
- Platycercus icterotis xanthogenys,

Species
Common and binomial names	Photograph	Description	Range
Western Rosella (Platycercus icterotis)		26 cm (10 in) long, the smallest rosella. The male is mainly red with yellow cheek patches, green rump, and a dark green tail. The female is duller, with a mainly green head, reddish forehead, yellow cheeks, and variegated green-red underparts. Colours of scalloped back feathers differ between two subspecies. The bill is whitish and the irises are dark brown.	Southwest Australia
Crimson Rosella (Platycercus elegans)		36 cm long, five subspecies, three of which are actually crimson. The red is replaced by yellow in the case of var. flaveolus and a mixture of red, orange and yellow in the Adelaide Rosella.	East and Southeast Australia
Green Rosella (Platycercus caledonicus)		37 cm (14.5 in) long, the largest rosella. It has a yellow head and underparts with blue cheeks and a red frontal band above the bill. The feathers on the back and inner wings are black with narrow green margins at their tips, and the outer wing feathers are blue and green. Rump olive and the tail green. Irises are dark brown and the bill is light grey.	Tasmania
Pale-headed Rosella (Platycercus adscitus)		30 cm long, mostly covered in blue except for the upper breast and head which are cream-yellow, the tail is blue-black and green, and an area around the vent is red. Two subspecies.	Eastern Australia
Eastern Rosella (Platycercus eximius)		30 cm (12 in) long. Red head and white cheeks. The upper breast is red and the lower breast is yellow fading to pale green over the abdomen. The feathers of the back and shoulders are black, and have yellowish or greenish margins giving rise to a scalloped appearance that varies slightly between three subspecies and the sexes. The wings and lateral tail feathers are bluish while the tail is dark green.	Australia and Tasmania. Introduced to New Zealand where feral populations are found in most of North Island and the hills around Dunedin in the South Island
Northern Rosella (Platycercus venustus)		28 cm long, forehead, crown and nape are black in colour with white-on-blue cheek-patches. The back and wing feathers are blackish with yellow borders, while the feathers of the belly, chest and rump are pale yellow with black borders giving rise to a scalloped appearance, tail is bluish green. The bill is pale grey.	The Northern Rosella is found from the Gulf of Carpentaria, through Arnhem Land to the Kimberleys in open savannah country, Australia.