Plant of the Week

Showy Evening Primrose (Oenothera speciosa L.)

By David Taylor

Showy evening primrose, or pinkladies, is in the Onagraceae (evening primrose) family. This family contains about 150 species worldwide that range from small to large, often weedy herbs. They are native to the Americas, but have been introduced to the Old World. Some species are grown as ornamentals. Members of this genus often cross and form hybrids. This evening primrose species is found from Pennsylvania west to Nebraska, south to Texas then eastward to Florida. It is also known from Connecticut, New Mexico, Arizona, Utah, and California. It also occurs in northern Mexico. The native range is southern Missouri through the southeast and to the southwest.

This evening primrose grows from extensive slender rhizomes that may be more than a foot below the surface. Overtime, a single plant can produce a clump of 200 centimeters (about 6 feet) in diameter. Simple toothed leaves emerge in late spring and are about 3 to 8 centimeters (1 to 3 inches) long and about 2 centimeters (3/4 inches) wide . They are on short petioles with fringe-like segments near the petiole. Flowers are produced in small clusters at the end of long stems. They are white tinged with pink to pinkish and 3.5 to 9 centimeters (1.5 to 3.6 inches) across. Flowering begins in May and may continue to October depending on location.

The evening primrose common name comes from tendency of flowers in this family to open in the afternoon or evening, although some open in the morning. The fruit is a narrow capsule 12 to 18 millimeters (0.5 to 0.7 inches) long. Typical habitat is in prairie, fields, meadows and open woodlands, often in sandy soil. It is usually abundant in these locations. It is available from many native plant nurseries and while attractive, it can become extremely weedy in a garden. Never dig plants from the wild.

For More Information

• PLANTS Profile - Oenothera speciosa, showy evening primrose, pinkladies