Kansas Wildflowers and Grasses - Serrate-leaf evening primrose

SERRATE-LEAF EVENING PRIMROSE

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Oenothera serrulata Nutt.

[=Calylophus serrulatus (Nutt. ) Raven]

Mitchell County, Kansas

Perennial

Height: 6-30 inches

Family: Onagraceae - Evening Primrose Family

Flowering Period: May, June, July, August

Also Called:

Plains yellow primrose.

Stems:

Erect or decumbent, few to many, simple or branched from base, glabrous or hairy.

Leaves:

Alternate, simple, sessile, linear-oblong to narrowly lanceolate, 1/2 to 4 inches long, less than 1/2 inch wide, nearly glabrous or hairy above, gray-hairy below, often folded lengthwise; margins toothed or entire; tips pointed to rounded.

Inflorescences:

Solitary flowers, in axils of upper leaves.

Flowers:

1-2 inches wide, floral tubes less than 3/5 inch long; sepals 4, distinctly keeled; petals 4, 1/4 to 3/4 inch long, about as wide, bright yellow, fading to pale yellow or pinkish; stamens 8; stigma disc-shaped, 4-lobed, extending nearly to tips of stamens.

Fruits:

Capsules, linear-cylindric, 1/2 to 1 inch long, 4-angled, thick-walled, slightly grooved, silvery-hairy; seeds many, small, brown.

Habitat:

Dry rocky, gravelly, or sandy prairies, hillsides, roadsides, and open woods.

Distribution:

Throughout Kansas.

Forage Value:

Serrate-leaf evening primrose is palatable and nutritious to livestock, particularly the new growth. It decreases on overgrazed rangeland.

Comments:

Serrate-leaf evening primrose is drought resistant. In addition to an extensive root system, the leaves fold in the midday sun, reducing water loss through their surfaces.

Serrate-leaf evening primrose sepals and leaves