Angiosperms: Dicotyledons

Onagraceae
Evening Primrose Family

• Stem: perennial; 2’ to 3’ tall; much-branched above the middle; smooth except in the inflorescence.
• Leaves: opposite; oval, tapering to both ends; 2 1/2” by 3/8”; sessile; fine-toothed margins; smooth above and below.
• Inflorescence: many short, branching flower stalks from the stem tip and upper leaf axils; hairy; to 12” long, cylindrical.
• Flowers: petals pink, 1/8” long, sepals 1/16” long, both attached at the top of the ovary (inferior ovary); ovary 3/4” long, very narrow, 1/32” in diameter; flowering from early August to early September.
• Fruits: capsules, 1 1/2” long by 1/16” in diameter; splitting from the tips into four segments; seeds tiny, 1/32” long, with hairy plumes attached at one end; fruiting begins in mid-August; seeds begin flying in early September.
• Habitat: frequent in marshes, in low woods, on stream banks; often with some disturbance; seldom found on prairies; less frequent to the south and west.
• Bibliography from Biodiversity Heritage Library
• Vascular Plants of Iowa