From Garthwaite and Lawson:
In North America, this European introduction is morphologically very similar to Porcellionides pruinosus which is also from Europe. Although it is impossible to assign individuals of these two taxa definitively to species without fresh specimens, all recent collections of Porcellionides from California have been P. floria with the exception of a single collection of P. pruinosus from Death Valley, Inyo County. On this basis we assume all previous reports of P. pruinosus from he San Francisco Bay Area to be P. floria. In the Bay Area, P. floria was reported by Stuzberg from San Francisco, San Francisco County.