Asperum:  Answers to key questions in Budd's Flora and Flora of Alberta leading to this species.   plants 2-4 dm high pubescence of leaves mostly of bifid hairs flowers smaller than 2-4 cm across petals yellow petals 12-20 mm long siliques 2-10 cm long, not 1-3 cm long

 

Erysimum: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.  Note that there is a contradiction in the answers from Flora of Alberta (FOA) regarding whether the leaves are entire or not.  The upper leaves of this species are entire; the lower leaves slightly toothed.  Note also that the length of the petals specified in this genus key by FOA contradicts the length specified by FOA in the above species key. plants more or less pubescent stem hairs attached by the middle, appressed leaves NOT oval to elliptical, NOT entire (FOA) leaves simple, entire or slightly toothed (FOA) basal leaves NOT lyrate-pinnatifid cauline leaves NOT cordate-clasping stem leaves entire to dentate, not lobed (BF) flowers yellow petals less than 7 mm long (FOA) fruit pod-like (silique or silicle) pod dehiscent by 2 valves pods not compressed at right angles to the central partition pod more than 4 times as long as broad pod with a short slender beak or beakless seeds in 1 row in each locule seeds globose, ovoid or ellipsoid; NOT flattish

 

Cruciferae: Answers to key questions in Budd's Flora leading to this family. herbs plants terrestrial or semi-aquatic plants not with colored milky juice plants with more than one normal leaf leaves without stipules, or having glands some or all leaves alternate calyx regular 4 sepals corolla regular in shape 4 petals stamens usually 6, 4 long and 2 short ovary superior 1 or 2 carpels