This study examines five taxa of Sisyrinchium (Iridaceae) known to occur in Virginia: S. angustifolium Miller, S. arenicola Bicknell, S. atlanticum Bicknell, S. mucronatum Michx., and S. albidum Raf. Chromosome numbers were determined for all species except the latter. Sisyrinchium angustifolium Mill. had a chromosome number of n = 48, while the other three species had counts of n = 16. A nomenclatural framework which rejected the application of the name S. bermudiana L. to the blue-eyed grasses of North America was followed.