Arenosa:  Answers to key questions in Budd's Flora, Flora of Alberta, and Flora of the Great Plains leading to this species.   plants annual or short-lived perennials; NOT [plants perennial] plants NOT densely tufted inner basal leaves flat; NOT [inner basal leaves involute] inner basal leaves generally dentate or at least angular; NOT [inner basal leaves usually entire] inflorescence and infructescence often secund pedicels distinctly recurved; NOT [pedicels erect, straight or slightly curved], NOT [pedicels generally sigmoid] flowers reddish yellow; NOT [flowers bright yellow] styles generally 3.0-5.5 mm long; NOT [styles generally 1.0-2.5 mm long] pods more or less globose; NOT [pods ovate] pods densely pubescent; NOT [pods glabrous or nearly so] valves usually glabrous on the interior; NOT [valves often pubescent on the interior]

 

Lesquerella: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.    plants perennial; NOT [plants mostly annual] plants NOT alpine hairs on plant branched or starry; NOT hairs on plant simple leaves less than 1 cm wide; NOT [leaves up to 1 cm wide] leaves lanceolate to oblanceolate; NOT [leaves mostly spatulate] leaves more or less entire; NOT [leaves deeply serrate to pinnate or bipinnate] upper stem leaves, if any, NOT auriculate and clasping petals yellow; NOT [white] petals 4-8 mm long; NOT [petals 9-12 mm long] pods not inflated; NOT [pods conspicuously inflated] pods not much flattened, more or less round in cross section; NOT [pods much flattened, at least twice as wide as thick], NOT [pods compressed at right angles to the central partition] pods usually not more than 3 times as long as wide; NOT [pods usually at least 4 times as long as wide] pods often less than 8 mm long; NOT [pods 8-15 mm long] valves of pods with no nerves; NOT [valves of pods with one nerve] pods opening lengthwise; NOT [pods not opening or breaking off at maturity] seeds flat; NOT [seeds round]

 

Cruciferae:  Answers to key questions in Budd's Flora leading to this family. herbs; NOT [shrubs or trees] plants terrestrial or semiaquatic; NOT [plants aquatic, leaves submerged or floating] plants NOT with colored milky juice plants with more than one normal leaf some or all leaves alternate; NOT [leaves opposite, whorled, or basal] leaves without stipules, or having glands; NOT [leaves with stipules] flowers with two floral rings, and with each petal distinct from the others calyx regular; NOT [calyx irregular, some sepals smaller than others] sepals 4 corolla regular in shape petals 4; NOT 5 stamens usually 6, four long and two short; NOT [stamens 6, of equal length], NOT [stamens usually more than 10] ovary superior; NOT inferior carpels 1 or 2; NOT [carpels 3-5]