Kansas Wildflowers and Grasses - Missouri evening primrose

MISSOURI EVENING PRIMROSE

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Oenothera macrocarpa Nutt. subsp. macrocarpa

Tallgrass Prairie National Preserve, Chase County, Kansas

Perennial

Height: 6-18 inches

Family: Onagraceae - Evening Primrose Family

Flowering Period: May, June, July

Stems:

Decumbent to ascending, few to many, sometimes branched, frequently reddish, appressed-hairy.

Leaves:

Alternate, simple, stalked or uppermost sessile, numerous, oblanceolate to elliptic-lanceolate, 2 to 6 inches long, .25 to 1.5 inches wide, thick, leathery, green, young leaves and buds grayish, appressed-hairy; margins entire or shallowly toothed; tips pointed or rounded; mature buds usually erect.

Inflorescences:

Solitary flowers, in leaf axils.

Flowers:

Showy, 3 to 6 inches wide, floral tubes 2 to 6 inches long; sepals 4, linear-lanceolate to lanceolate, bending abruptly downward and toward 1 side, often purple-spotted; petals 4, 1 to 2 inches long, nearly as wide, yellow, fading reddish or orange; stamens 8, filaments nearly as long as petals; stigma deeply 4-lobed, cross-shaped.

Fruits:

Capsules, 1.5 to 4 inches long, conspicuously 4-winged; seeds numerous, small, angular, corky.

Habitat:

Dry rocky prairies, limestone hillsides, road-cuts, and disturbed areas.

Distribution:

East 3/4 of Kansas.

Comments:

The flowers open near sunset and close by mid-morning of the following day. Night-flying moths pollinate the flowers, which face upward at first, and then turn downward after pollination. Missouri evening primrose is drought-resistant. Three other subspecies of Oenothera macrocarpa occur in Kansas.

Missouri evening primrose leaves