Philotiella leona Hammond & McCorkle, n. sp. (Lycaenidae), is described from the volcanic ash fields of the Oregon Cascade Range. Both sexes are compared with P. s. speciosa in wing color pattern and genitalia. In addition, preliminary comparisons suggest that the bohartorum-purisima complex of subspecies now assigned to P. speciosa may prove to be a third species of Philotiella for North America. The larval foodplant and ecology of P. leona are also discussed.
