Black Mustard

Black Mustard
Black Mustard. Brassica nigra.
Brassicaceae, the mustard family.

Plant: Branching plant, to 6' high, sparsely leafed except at base, with elongating, terminal clusters of bright yellow flowers. Annual.
Flowers: Yellow, about 1/2" across, with four petals, and four narrow sepals, in elongating clusters (racemes) at the ends of the several branches.
Leaves: Alternate, stalked, lower ones lobed and toothed, ovate in overall outline, 1"-3"; upper ones smaller, more lanceolate, often unlobed.
Fruit: A narrow, beaked capsule, square in cross-section, 1/2" long, and closely pressed to the stem.
Blooming: June-September
Habitat: Fields, waste areas, roadsides.

Comments: A European immigrant, one of several yellow mustards in our area distinguished by characteristics of the leaves and fruit. The young leaves can be cooked and eaten, and the seeds are used in condiments.

Where to find it: I have found this plant only occasionally in the park; the common yellow mustard is winter cress (Barbarea vulgaris), easily distinguished by fruit that stick out from the stem and distinctly different, mostly sessile leaves.