Tag: Evening Primrose

  • Evening Primrose (Oenothera biennis)

    Oenothera biennis
    Photographed August 30.

    A tall and stately weed whose flowers we almost never get to see in their full glory. It’s a night-bloomer, opening at dusk and fading in the early hours of the morning. It will, however, stay open on a rainy day; we found this plant blooming merrily out of a sidewalk crack on the South Side Slopes.

    Flowers. Pale yellow; four broad petals; cross-shaped anther in the middle; borne in branching racemes.

    Leaves. Lanceolate, sessile, slightly toothed; net-veined, with center rib often reddish toward base; alternate; thick on the stem, with branches or abortive branches in axils; mostly smooth.

    Stem. Stout; somewhat sticky; woody below, with dark brownish stripes; to 6 feet or more; much branched.

    Flower close up

    At one time this plant was placed in a genus Onagra, from which the family Onagraceae was named; but Gray and most modern botanists make that genus part of Oenothera.

    Gray describes the genus and the species:

    ONAGRA (Adans.) Ser. Stigma-lobes linear, elongated; flower-buds upright; petals yellow; fruit subcylindrical, elongated; seeds in 2 rotos in each cell; caulescent annuals or biennials.

    O. biennis L. (COMMON E.) Rather stout, erect, 3-15 dm. high, usually simple, more or less spreading-pubescent to hirsute; leaves lanceolate to oblong or rarely ovate-lanceolate, repandly denticulate, acute or acuminate; bracts lanceolate, shorter than or scarcely exceeding the capsules; calyx-tube 2.5-3.5 cm. long; petals yellow, obovate, 1.5-2.5 cm. long; pods more or less hirsute, narrowed almost from the base, 2-3.5 cm. long. (Onagra Scop.) —Open places, common.

    Oenothera biennis
  • Evening Primrose (Oenothera biennis)

    Photographed September 10.

    In cool weather it is sometimes possible to catch an Evening Primrose open in the middle of the day, though the flowers usually close by the middle of the morning. In an earlier article, we gave this description of it:

    A tall and stately weed whose flowers we almost never get to see in their full glory. It’s a night-bloomer, opening at dusk and fading in the early hours of the morning.

    Flowers. Pale yellow; four broad petals; cross-shaped anther in the middle; borne in branching racemes.

    Leaves. Lanceolate, sessile, slightly toothed; net-veined, with center rib often reddish toward base; alternate; thick on the stem, with branches or abortive branches in axils; mostly smooth.

    Stem. Stout; somewhat sticky; woody below, with dark brownish stripes; to 6 feet or more; much branched.