TANSY MUSTARD, Descurainia pinnata (Wait.) Britt. 1, stem; 2, upper portion of flowering plant; 3, young plant; 4, lower stem and roots; 5, seed; 6, seed pod; 7, flower. Annual or biennial, reproducing by seeds. Stems erect, slightly hairy, 1 to 3 feet (30 to 90 cm) high, much branched above. Leaves light green, alternate, 2 to 4 inches (5 to10 cm) long, finely divided, almost fernlike. Flowers small, pale yellow, produced on elongated racemes. Seed pods narrow, smooth, slightly curved, 1/2 to 3/4 inch (1.3 to 1.9 cm) long, 2-celled, many-seeded. Seeds small, oblong to 3-angled with a groove on one side, dull red or light brown. Found in cultivated fields, pastures, meadows, waste places, and roadsides. The plant can produce a rank growth, crowding out grain and reducing crop yields. A similar species, flixweed (Descurainia sophia), is also found in abundance in much of the same area.