Bog St. Johnswort, Bog St. John'swort, Bog St. John's Wort, Creeping St. Johnswort, Tinkers Penny, Tinker's Penny: Hypericum anagalloides - Plants matted, less than 10 cm high. Petals less than 6 mm long, about equal to the sepals. Stamens less than 50. Plants of very moist areas.
Sweet Amber: Hypericum androsaemum - Introduced and not naturalized.
Aaron's Beard, Creeping St. John's Wort, Goldflower, Great St. John's-wort, Rose of Sharon: Hypericum calycinum - Introduced and not naturalized.
Common St. Johnswort, Common St. John's-wort, Klamathweed, Klamath Weed: Hypericum perforatum (Synonym: Hypericum perforatum ssp. perforatum) - Plants erect, generally over 10 cm high. Petals much greater than 6 mm long, much longer than the sepals. Stamens greater than 50. Sepals linear-lanceolate in shape, 3-5 times long as wide. Plants with taproot and some short rhizomes or stolons.
Norton's St. Johnswort, Scouler's St. Johnswort, Scouler's St. John's-wort, Western St. John's-wort: Hypericum scouleri (Synonyms: Hypericum formosum, Hypericum formosum ssp. nortoniae, Hypericum formosum ssp. scouleri, Hypericum formosum ssp. scouleri var. nortoniae, Hypericum formosum ssp. scouleri var. scouleri, Hypericum formosum var. nortoniae, Hypericum formosum var. scouleri, Hypericum nortoniae, Hypericum scouleri ssp. nortoniae, Hypericum scouleri ssp. scouleri) - Plants erect, generally over 10 cm high. Petals much greater than 6 mm long, much longer than the sepals. Stamens greater than 50. Sepals triangular to ovate-lanceolate in shape, less than 3X as long as wide. Plants with widespread stolons and rhizomes, but not with a taproot. Oregon currently (August 2011) accepts the taxonomic nomenclature for this taxon, while Washington accepts that shown immediately below (2 subspecies):
Norton's St. Johnswort: Hypericum scouleri ssp. nortoniae (Synonyms: Hypericum formosum ssp. nortoniae, Hypericum formosum ssp. scouleri var. nortoniae, Hypericum formosum var. nortoniae, Hypericum nortoniae, Hypericum scouleri ssp. nortoniae) -
Scouler's St. Johnswort, Scouler's St. John's-wort, Western St. John's-wort: Hypericum scouleri ssp. scouleri (Synonyms: Hypericum formosum, Hypericum formosum ssp. scouleri, Hypericum formosum ssp. scouleri var. scouleri, Hypericum formosum var. scouleri, Hypericum scouleri ssp. scouleri) -