The shrubby reed-mustard (Glaucocarpum suffrutescens) is a perennial herb in the mustard family (Brassicaceae). The clumped stems are 10 to 25 cm (4 to 12 inches) tall arising from a branching woody root crown. The leaves are entire with a smooth margin, 1.0 to 2.5 cm (0.4 to 1 inch) long and 0.3 to 1.0 cm (0.12 to 0.4 inch) wide. The leaf blades are alternately arranged on the stem and are attached to the stem by a short petiole. The shrubby reed-mustard flowers have petals that are light yellow or greenish yellow and spatulately shaped measuring about 10 mm (0.4 inch) long and 3 mm (0.12 inch) wide. The entire flowers are displayed in a raceme of, commonly, 5 to 20 flowers at the end of the plant’s leafy stems (Rollins 1938; Welsh and Chatterley 1985; Welsh et al. 1987).