Banksia seminuda subsp. remanens and B. occidentalis subsp. formosa are described and illustrated. Both have smaller leaves, are more floriferous and are smaller shrubs than their respective nominate subspecies. Both have outstanding horticultural merit. Their conservation in the wild will necessitate careful management, as both new subspecies may be killed by fire, and both have restricted geographical distributions. B. seminuda subsp. remanens and B. occidentalis subsp. formosa each have a distribution and morphological features suggesting that they are relictual taxa of Western Australian lineages that show the closest relationships to eastern Australian members of Banksia section Oncostylis.