YELLOW ROCKET, Barbarea vulgaris R. Br. 1, upper part of plant; 2, lower part of plant; 3, pods; 4, flower; 5, seed; 6, root. Winter annual, biennial, or perennial, reproducing by seed, taprooted. Stems numerous, growing from a crown, upright, 1 to 2 feet (30 to 60 cm) tall, branched near top, smooth, and angular or ridged. Leaves pinnately divided; basal leaves have a large terminal lobe, are 2 to 8 inches (5 to 20 cm) long, and form a dense rosette; stem leaves become progressively shorter with top leaves about 1 inch (2.5 cm) long and less deeply lobed. Flowers bright lemon-yeIlow, 4-petaled (typical mustard flower), borne in spikelike racemes on end of each branch. Bloom in late April and early May. Pods about 1 inch (2.5 cm) long, about 3/32 inch (2.4 mm) in diameter, nearly square in cross section. Seeds light yellow to yellowish-brown, 1/32 inch (0.8 mm) long, ripening in May and early June. Found along roadsides, in pastures, and in timothy, clover, and alfalfa fields, where it matures before the crop is cut. Seeds live several years in the soil. Also known as winter cress.