The species are of various sizes, often green-plumaged above and yellow below, or more subdued with greyish-green to greyish-brown colours, varying little or not at all with the seasons. The tails are not very long and contain 12 feathers (unlike the similar Abroscopus species, which have 10 tail feathers).
Alström, Per; Ericson, Per G.P.; Olsson, Urban & Sundberg, Per (2006): Phylogeny and classification of the avian superfamily Sylvioidea. Molecular Phylogenetics and Evolution38(2): 381–397. doi:10.1016/j.ympev.2005.05.015
Baker, Kevin (1997): Warblers of Europe, Asia, and North Africa. Princeton University Press, Princeton, N.J. ISBN 0691011699