Technical Abstract: The strawberry genus Fragaria L. (Rosaceae) has a base chromosome number of x = 7 with economically important diploid (F. vesca L.), hexaploid (F. moschata Weston), octoploid (F. ×ananassa Duchesne ex Rozier), or artificially developed decaploid (F. ×vescana Rud. Bauer & A. Bauer) cultivars. Since early in the 18th century, when American strawberries were first introduced into Europe, ploidy differences were recognized as a significant crossing barrier. During the past several decades, breeders have strategically expanded their parental reference material by incorporating selected wild species to reconstruct the cultivated F. ×ananassa gene pool. While ploidy has been reported for world species, collections from the wild are revealing unexpected cytotypes. The occurrence of unreduced gametes in many Fragaria species is not infrequent. Considering evolutionary time, the opportunity for the introgression of sympatric Fragaria species, despite widely disparate ploidy levels, is not trivial. This paper reviews reports of wild triploid, pentaploid, hexaploid, eneaploid, and decaploid cytotypes from California and Oregon, where sympatric Fragaria species occur. Researchers should be aware of unexpected ploidy levels in potential parental resources which could reduce fecundity in subsequent selection generations. The identification of multiple wild decaploid sources could establish foundation germplasm for a new class of cultivated strawberries.