Range: Labrador to Florida, westward to the Rocky Mountains. Habitat: Dry soil; fields, meadows, roadsides, waste places.
The long, stout taproot of this plant is used in Germany as a table vegetable, like parsnips, and its young crown leaves are blanched and used for salad. It is also medicinally valuable. Collectors receive about five cents a pound for the plants pulled entire in mid-flowering time and dried in the shade.
Stem two to six or more feet tall, rather stout, usually simple, more or less hairy. Root leaves lance-shaped, three to six inches long, the surface dark green, rough-hairy, slightly toothed, tapering to a petiole; stem leaves much smaller, alternate and sessile. Flowers in terminal leafy-bracted spikes, sessile, the calyx-tube sometimes two inches long, its four lobes reflexed and falling away; stamens eight, inserted on the top of the calyx-tube; style with deeply four-cleft stigma; ovary below the long calyx-tube, itself much elongated and four-celled; the four broad, sulfur-yellow petals are rolled in the bud, and at the falling of twilight their unfolding is so swiftly accomplished that one may "see her
Fig. 206. - Evening Primrose (Oenothera biennis). X 1/4 doff her soft green hood and blossom -with a silken burst of sound." Sweet odors pour from the pale yellow cups and attract the night-flying moths, which fertilize the flowers, and in the morning sunlight the blossoms droop and wither. Capsules an inch or more long, four-celled, slightly hairy, splitting at the top into a slender, vase-like shape; they sway on the tall stalks all winter and birds destroy many of the seeds in their foraging. (Fig. 206.)
Cutting crown leaves from the roots with spud or hoe in the first season; close cutting of flowering stalks while in early bloom; plants with capsules formed should be cut and burned, as they ripen on the stalks.