Cascade Wallflower, Sand-dwelling Wallflower: Erysimum arenicola (Synonyms: Cheiranthus arenicola, Erysimum arenicola var. arenicola, Erysimum arenicola var. torulosum,Erysimum perenne var. tephrinum, Erysimum torulosum) -
Douglas' Wallflower, Prairie Rocket, Rough Wallflower, Sanddune Wallflower, Western Wallflower: Erysimum capitatum var. capitatum (Synonyms: Erysimum arkansanum, Erysimum asperum, Erysimum asperum ssp. capitatum, Erysimum asperum var. arkansanum, Erysimum asperum var. capitatum , Erysimum capitaum var. stellatum, Erysimum capitatum var. washoense, Erysimum elatum, Erysimum moniliforme, Erysimum wheeleri) - Petals 15-25 mm long, lemon yellow to orange or reddish. Fruits 4-angled, 3-15 cm long on spreading to ascending pedicels.