During the first year of growth, the roots can be cooked and eaten. This is by far the most common evening primrose (Oenothera) in Illinois. Although it favors disturbed weedy areas, this species is sometimes found in prairies and other natural areas. Common Evening Primrose can be distinguished from other Oenothera spp. on the basis of its tallness (often exceeding 3' in length), the shape of its seed capsules (rounded edges, rather than sharply angular), the shape of its leaves, and the size of its flowers. There is significant variation in the hairiness of individual plants. For more information about these distinctions, see Mohlenbrock (2002). Return

This native biennial plant can be 7' tall, although it is often shorter. There is usually a central stem with alternate leaves, but sometimes there will be multiple stems in open areas, creating a bushy appearance. The stems are light green or red, and are covered with white hairs. The light or olive green leaves are up to 8' long and 2' wide, but usually smaller. They are lanceolate and resemble willow leaves. The margins of the leaves are smooth or slightly dentate, and are nearly hairless. Smaller secondary leaves often appear at the axils of major leaves on the central stem. A panicle of pale yellow flowers occurs at the apex of the plant (or at the ends of major stems, if the plant is bushy). Each flower is about 1' across when fully open, with 4 petals and prominent stamens, and a long green calyx. The flowers remain open from evening to early morning, but will remain open longer on cloudy days. They have a mild lemony scent, and bloom from mid-summer to fall on mature plants. Long narrow seedpods develop, which split open from the top to release many tiny, irregular brown seeds. They are small enough to be dispersed by the wind, and can remain viable in the soil after 70 years. The root system consists of a fleshy taproot. Cultivation

General: Evening Primrose Family (Onagraceae). Oenothera biennis is a biennial, herbaceous forb. The family is so-named because the flowers are partially to fully closed during the day and open in the evening. The bright yellow to gold corolla is 2-5 cm wide, with four petals. The fragrant flowers usually last only one to two days. The erect stem, which sometimes branches near the top, can be covered with hairs. The plant grows from 3-25 dm tall. Basal leaves, which form a rosette, are from 10-30 cm long. The stem has alternate, lanceolate-shaped leaves, 2.5-15 cm long, that are shallowly toothed and wavey at the edges. The leaves are usually hairy. The plant flowers can from June through October.

Distribution: For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.

Weedy evening-primrose, German rampion, hog weed, King’s cure-all, fever-plant

Common Evening Primrose occurs in every county of Illinois (see Distribution Map). It is a common plant that is particularly conspicuous during late summer or fall. Disturbed areas are favored in both natural and developed habitats, including mesic to dry black soil prairies, sand prairies, thickets, glades, lakeshore dunes, abandoned fields, roadsides and railroads, slopes of drainage ditches, vacant lots, etc. Sometimes this plant is cultivated in wildflower gardens, from which it may escape. Faunal Associations

Oenothera biennis subsp. centralis Munz:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Oenothera biennis var. pycnocarpa (G.F. Atk. & Bartlett) Wiegand:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Oenothera biennis L.:
Bhutan (Asia)
Canada (North America)
Japan (Asia)
Kyrgyzstan (Asia)
Kazakhstan (Asia)
Russian Federation (Asia)
South Korea (Asia)
United States (North America)
South Africa (Africa & Madagascar)
China (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Anhui, Guangdong, Guangxi, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jilin, Liaoning, Nei Mongol, Sichuan, Taiwan, Yunnan [Bhutan, Japan, Kazakhstan, Korea, Kyrgyzstan, Russia; native to E North America; widely naturalized in SW Asia, Europe, Pacific islands (New Zealand), and S South America].

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Common evening-primrose grows in dry open fields, along roadsides, railroad embankments, waste areas and in open woods.

Herbs erect, biennial, with basal rosette. Stems 30-200 cm tall, simple or sparsely branched, densely to very sparsely strigillose and with longer spreading and usually pustulate-based hairs, inflorescence often also glandular puberulous. Leaves green or pale green, with inconspicuous veins, sessile or shortly petiolate; rosette blade 10-30 × 2-5 cm; cauline blade narrowly oblanceolate to elliptic, 5-22 × (1-)1.5-5(-6) cm, base acute to attenuate, margin dentate to subentire, often lobed near base, apex acute. Inflorescence a dense mostly unbranched spike. Flowers open near sunset; floral tube (2-)2.5-4 cm. Sepals 1.2-2.2(-2.8) cm, with free tips 1.5-3 mm, erect. Petals yellow, fading to orange, 1.2-2.5(-3) cm. Anthers 3-6(-9) mm; pollen ca. 50% fertile. Ovary densely glandular puberulous and sparsely villous or with very sparse pustulate-based hairs, sometimes only densely strigillose; stigma surrounded by anthers. Capsules green, narrowly lanceoloid to lanceoloid, 2-4 cm, sessile. Seeds in two rows per locule, brown to nearly black, 1.1-2 mm, irregularly pitted. Fl. Jul-Oct, fr. Jul-Nov. 2n = 14, permanent translocation heterozygote; self-compatible, autogamous.

Oenothera muricata Linnaeus; O. suaveolens Desfontaines; Onagra biennis (Linnaeus) Scopoli; O. muricata (Linnaeus) Moench.

Common Evening Primrose occurs in every county of Illinois (see Distribution Map). It is a common plant that is particularly conspicuous during late summer or fall. Disturbed areas are favored in both natural and developed habitats, including mesic to dry black soil prairies, sand prairies, thickets, glades, lakeshore dunes, abandoned fields, roadsides and railroads, slopes of drainage ditches, vacant lots, etc. Sometimes this plant is cultivated in wildflower gardens, from which it may escape. Faunal Associations

Common in open, disturbed areas; near sea level to 1500 m.

These plants do best in well-drained soils in full sun. They can be easily grown from seed. The seeds are ripe when the seed capsule begins to split open, usually in October. To insure even planting, mix the seeds with a small amount of sand prior to sowing. The seeds usually germinate within four weeks. Thereafter, the plants will generally self-sow. Please use care when cultivating this plant as it has become invasive in many parts of the world.

Oenothera biennis (Common Evening Primrose)
(Bees collect pollen or suck nectar as indicated below; hummingbirds & moths suck nectar; most observations are from Robertson, otherwise they are from Moure & Hurd as indicated below)

Birds
Trochilidae: Archilochus colubris sn fq

Bees (long-tongued)
Apidae (Apinae): Apis mellifera sn cp fq; Apidae (Bombini): Bombus pensylvanica sn cp fq; Anthophoridae (Eucerini): Anthedonia compta sn cp fq olg, Melissodes bimaculata bimaculata cp, Svastra obliqua obliqua cp; Megachilidae (Megachilini): Megachile mendica cp

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon virescens cp, Lasioglossum oenotherae cp olg (MH); Halictidae (Nomiidae): Nomia nortoni nortoni cp

Moths
Sphingidae: Hyles lineata sn

In Great Britain and/or Ireland:
Foodplant / parasite
Erysiphe howeana parasitises Oenothera biennis

Foodplant / feeds on
pycnidium of Phoma coelomycetous anamorph of Phoma onagracearum feeds on Oenothera biennis

Foodplant / spot causer
punctiform aggregated in spot centre, blackish-brown pycnidium of Septoria coelomycetous anamorph of Septoria oenotherae causes spots on live leaf of Oenothera biennis

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 14
Species With Barcodes: 1

Rounded Global Status Rank: G5 - Secure

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

These species are introduced in Switzerland.

These plants are readily available from commercial sources. Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”

Please contact your local agricultural extension specialist or county weed specialist to learn what works best in your area and how to use it safely. Always read label and safety instructions for each control method. Trade names and control measures appear in this document only to provide specific information. USDA, NRCS does not guarantee or warranty the products and control methods named, and other products may be equally effective.

This plant may become weedy or invasive in some regions or habitats and may displace desirable vegetation if not properly managed. Please consult with your local NRCS Field Office, Cooperative Extension Service office, or state natural resource or agricultural department regarding its status and use. Weed information is also available from the PLANTS.

Ethnobotanic: The Cherokee, Iroquois, Ojibwas, and Potawatomi were among several Native American tribes that used common evening-primrose for both food and for medicinal purposes. The roots were boiled and eaten like potatoes. The young leaves were cooked and served as greens. The shoots were eaten raw. A tea was made from the plant and used as a dietary aid or stimulant to treat laziness and “overfatness.” A hot poultice made from the pounded roots was applied externally to treat piles and boils. A poultice made from the entire plant was used to treat bruises. The roots were chewed and rubbed onto the muscles to improve strength. The plant was used to treat pain associated with menstruation as well as bowel pain. Handfuls of people still use the plant today, medicinally and for food.

Other: Common evening-primrose is commercially cultivated in over 15 countries for its oil which contains the essential fatty acids, linoleic acid and gamma linolenic acid (Kemper 1999). When the seedpods ripen, the tall stalks can be cut and used as interesting additions to dried arrangements.

Wildlife: Hummingbirds visit the flowers to obtain nectar and insects to eat. The seed capsules provide food for many other birds during the winter months. It is thought that the plants are pollinated by night-visiting hawk moths, which feed on their nectar. Japanese Beetles prefer the leaves of common evening-primrose to those of other garden plants.

The seeds of this species contain gamma linolenic acid (GLA), an anti-inflammatory compound of potential therapeutic use for cardiovascular disorders, arthritis, and other human diseases. The cultivation of these plants as a source of GLA has increased recently, and the species has become naturalized widely in China.