Previously placed in Sylvia (del Hoyo and Collar 2016) but moved to current genus following Cai et al. (2019). Until recently considered to constitute several species, with splits of althaea and minula (with margelanica) (Sibley and Monroe 1990, 1993) from curruca (AOU 1998 and supplements; Dowsett and Forbes-Watson 1993; Sibley and Monroe 1990, 1993), and this may ultimately be more appropriate. Nuclear DNA, however, fails to support clades based on mtDNA, and, although althaea is relatively well marked, characters used to define species (and subspecies) limits prove too weak for taxa to pass tests of diagnosability (Olsson et al. 2013b). Treatment of these forms under a single species currently therefore inevitable (Dickinson and Christidis 2014).Geographical variation largely clinal, subspecies halimodendri intergrading widely with nominate in S Siberia. Proposed subspecies caucasica (Turkey, Caucasus and N Iran) and zagrossiensis (SW Iran) barely separable from nominate; similarly, telengitica (Russian Altai and Mongolia) included in margelanica. Proposed subspecies snigirewskii (Turkmenistan) largely inseparable from minula, and jaxartica (S Kazakhstan) falls within range of clinal variation of halimodendri; poorly differentiated chuancheica (upper R Huang He, S of Gobi, in N China) included in margelanica. Birds from Alai and Pamir Ranges E to Tien Shan sometimes separated as subspecies monticola, but not reliably distinguishable from those in rest of range of althaea. Six subspecies recognized.