Stems: slender. Leaves: pinnate; leaflets lanceolate, obtuse and acutely toothed. Flowers: small, yellow. Fruit: the siliques erect on ascending pedicels, linear, elongated.

A coarse uninteresting plant, with pinnately cut leaves, the tiny leaflets being sharply toothed. The flowers are small and yellow and the pods long and narrow.

Sisymbrium altissimum, or Tall Hedge Mustard, has tall freely-branching stems and lower leaves which are runci-nate-pinnatifid, the narrow lobes often auriculate, and smaller, very deeply cut upper leaves. The pale yellow flowers are inconspicuous. The pods are rigid, very long, divergent and hardly thicker than the short pedicels. This is an introduced plant.

Sisymbrium canescens, or Pale Tansy Mustard, is a soft-hairy species with long deeply cut leaves growing out almost at right angles from the stem; very small yellowish flowers and pods in long racemes.

Sisymbrium incisum, or Western Tansy Mustard, is a similar plant to the Pale Tansy Mustard, but is greener and less hairy, and has longer more slender pods and one-ranked seeds. The leaves have not such a fringed appearance as those of Sisymbrium canescens.