Recent molecular evidence that this form is less closely related than C. apolinari to other taxa in C. platensis#R prompted study here, resulting in finding that present species differs from C. platensis by its streaked black vs plain buffy-rufous rump (2); less distinctive streaking above (1); and relatively simple, uniform song, expressed as lower number of (truly) different phrases (2), and lower number of different notes (3), as well as a lack of longer notes (ns)#R. Monotypic.
S Canada (E Saskatchewan, C Manitoba, S Ontario and S Quebec) S in USA to N Kentucky, E Pennsylvania and New York; non-breeding winters from E USA (Virginia) S through coastal states to Texas and NE Mexico.
del Hoyo, J., Collar, N. & Marks, J.S. (2019). Sedge Wren (Cistothorus stellaris). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/1343993 on 19 April 2019).