Flower:

Flowers are single in the mid and upper leaf axils along branching stems, about 1 inch across with 4 heart-shaped yellow petals. In the center are 8 yellow stamens surrounding a bright yellow cross-shaped style that is mostly tucked inside the floral tube.

The 4 sepals are light green, narrowly lance-shaped and hang tightly down below the open petals, often in two pairs still attached along one seam (connivent) and with a short extension at the tip. Flowers are stalkless but the slender, pinkish tube (hypanthium) between the green ovary and the base of the sepals can be over an inch long and gives the appearance of a flower stalk. The hypanthium, ovary and sepals are all variously covered in long, spreading hairs.

Leaves and stems:

Leaves are alternate, lance-elliptic to oblong in outline, 1 to 4 inches long, up to 1 inch across, shallowly to deeply lobed along the edges, the lower leaves short-stalked, the upper stalkless. The upper surface is hairless to sparsely hairy, the lower more densely hairy. Stems are single, unbranched or branched from the base, erect to ascending to sprawling, and variously hairy.

Fruit:

Fruit is a slender, tubular capsule nestled in the leaf axil, ½ to 1¼ inches long, straight to slightly curved, with four small conspicuously flared lobes at the tip.

Inside are many light brown seeds, pitted all across the surface.

Notes:

Cut-leaved Evening Primrose has only been recorded twice in Minnesota, the first in 1945, the second in 1991, and both on sandy dunes in the northern Twin Cities metro area. The DNR considers it native to the state even though our 2 populations seem a bit dysjunct from the next closest neighbors in Wisconsin and those populations have not persisted; it is not listed as rare but the DNR does track it. A native annual or short-lived perennial that spreads by reseeding, it is considered something of a weedy species in parts of its range and an agricultural pest in parts of California. While the flowers resemble those of other Evening Primrose species, the lobed leaves and somewhat ragged growth habit separate it from the rest.