Long-tailed finch length. It has a prominent roundish black bib on its throat and upper chest and a long pointed black tail. It has pinkish brown upperparts with paler plumage below its bib over the lower breast and abdomen. It has a grey head, a white ear-patch, and black lores. It has black patches on its upper flanks and its rump and undertail coverts are white. The beak colour of the adult long-tailed finch varies from red through orange to yellow. The subspecies with red beaks is sometimes called Heck's grass finch "Poephila acuticauda hecki", and the nominate subspecies with orange or
Purple-crowned fairywren or reddish-chocolate in females) and the deep blue colour of their perky tails. Subspecies designation was originally based on differences in plumage coloration and body size of museum skins. More recent genetic analyses continue to support this split. The species was first collected in 1855 and 1856 by the surgeon J. R. Elsey at Victoria River and Robinson River. Alternative names for the purple-crowned fairywren include crowned superb warbler, lilac-crowned fairywren, lilac-crowned wren, mauve-crowned wren, purple-crowned warbler, purple-crowned wren, and purple-crowned wren-warbler. Two subspecies are currently recognized: The purple-crowned fairywren is a sexually dimorphic, small bird measuring approximately 14 cm