Western
Yellowcress is an annual or biennial with a single stem branched above or
a widespread cluster of branches from near the base.
The plant ranges from 10 to 40 cm tall with variable leaves
ranging from 2 to 7 cm long. They are oblong and entire to pinnatifid. The
lobes are entire to toothed and linear to ovate in shape.
The flowers are small and yellow, with the sepals 1 to 2
mm long and the petals of similar size. The siliques range from 6 to 15 mm
long and 1 to 1.5 mm wide. They are curved to straight and round in
cross-section.