Publication: Arbust. Amer. 111. 1785.
Origin: Native and introduced from further east of Washington
selected vouchers: WTU
Notes: The origin of this species in WA is unclear, as the Suksdorf collection from Bingen, Klickitat County in 1920 is the only specimen of this species at WTU. H&C do not list WA as within the range of P. americana, though they would have known about this specimen at the time they wrote the flora.