Perlesta placida (Hagen), long regarded as a widespread variable species, is a complex of at least 12 species which differ in pigmentation, egg morphology and male and female genital structures. Species removed from the synonymy of P. placida (= Chloroperla virginica Banks, 1898; = P. virginica immaculata Klapálek, 1921) include P. cinctipes (Banks, 1905), P. decipiens (Walsh, 1862) (= Perla brunnipennis Walsh, 1862, syn. n.; = Isoperla texana Banks, 1914, syn. n.; = P. costalis Klapálek, 1921, syn. n.) and P. nitida Banks, 1948. New species described include P. adena, P. baumanni, P. bolukta, P. browni, P. lagoi, P. nelsoni and P. shubuta. Lectotypes are designated for most older species, including P. frisoni Banks, 1948, which is also valid, and all are redescribed from types.