• Flowers:Yellow, fragrant, opening at evening, 1 to 2 in. across, borne in terminal leafy-bracted spikes. Calyx: tube slender, elongated, gradually enlarged at throat, the 4-pointed lobes bent backward; corolla of 4 spreading petals; 8 stamens; 1 pistil; the stigma 4-cleft.
• Stem: Erect, wand-like, or branched, 1 to 5 ft. tall, rarely higher, leafy. Leaves: Alternate, lance-shaped, mostly seated on stem, entire, or obscurely toothed.
• Preferred Habitat: Roadsides, dry fields, thickets, fence-corners.
• Flowering Season: June—October.
• Distribution: Labrador to the Gulf of Mexico, west to the Rocky Mountains.

Like a ball-room beauty, the Evening Primrose has a jaded, bedraggled appearance by day when we meet it by the dusty roadside, its erect buds, fading flowers from last night's revelry, wilted ones of previous dissipations, and hairy oblong capsules, all crowded together among the willow-like leaves at the top of the rank-growing plant. But at sunset a bud begins to expand its delicate petals slowly, timidly—not suddenly and with a pop, as the evening primrose of the garden does. Now, its fragrance, that has been only faintly perceptible during the day, becomes increasingly powerful. Why these blandishments at such an hour? Because at dusk, when sphinx moths, large and small, begin to fly, the primrose's special benefactors are abroad.

If a flower has not been pollenized during the night it remains open a while in the morning. Bumblebees now hurry in, and an occasional humming bird takes a sip of nectar. Toward the end of summer, when so much seed has been set that the flower can afford to be generous, it distinctly changes its habit and keeps open house all day.