As classified in WFO snapshot
June 2023
Warning: older classification
subspecies
Physocarpus alternans subsp. annulatus
J.T.Howell
This subspecies name was first published in Proc. Calif. Acad. Sci. , ser. 4, 20: 133 (1931)
This subspecies name has been reclassified since this snapshot. Its current preferred usage is a synonym .