This lovely plant should be grown more often. During the 19th century, this was a more popular garden plant, but it has since passed from favor and is not widely available. Prairie Sundrops resembles Oenothera fruticosa, but differs from the latter by its hairy leaves. The latter species has a range that lies east and south of Illinois, and is widely available through horticultural sources.

This native perennial plant is up to 2' tall and often bushy. The stems are covered with conspicuous white hairs. The sessile alternate leaves are up to 3" long and 1" wide, lanceolate or ovate, with smooth to slightly dentate margins. They are pubescent on both the upper and lower surfaces. The inflorescence at the top of the plant consists of a short cluster of flowers or hairy buds. These flowers are bright yellow and individually about 2" across. Each one has four large petals, large showy stamens, and fine white or transparent lines that radiate outward from the center of the flower. These lines function as nectar guides, and are more visible to insects than humans in the ultraviolet spectrum. The blooming period occurs during late spring or early summer and lasts about a month. The flowers bloom during the day and have a pleasant fragrance. The seeds are without tufts of hairs, while the root system is highly rhizomatous. In disturbed areas, colonies of plants are readily formed. The new growth during early spring and older foliage during the fall often acquire reddish tints.

Oenothera pilosella Raf.:
Canada (North America)
United States (North America)

Canada

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Prairie Sundrops occurs occasionally in the majority of counties in Illinois; it is uncommon or absent in central and NW Illinois (see Distribution Map). Habitats include moist to mesic black soil prairies, edges of pothole marshes, abandoned pastures, and prairie remnants along railroads.

Prairie Sundrops occurs occasionally in the majority of counties in Illinois; it is uncommon or absent in central and NW Illinois (see Distribution Map). Habitats include moist to mesic black soil prairies, edges of pothole marshes, abandoned pastures, and prairie remnants along railroads.

Oenothera pilosella (Prairie Sundrops)
(Long-tongued bees collect pollen or suck nectar; short-tongued bees collect pollen & are mostly non-pollinating; flies and beetles feed on pollen & are non-pollinating; other insects suck nectar; this plant was originally described as Oenothera fruticosa by Charles Robertson, but he was probably referring to Oenothera pilosella; one observation is by Moure & Hurd as indicated below, otherwise the observations are from Robertson)

Bees (long-tongued)
Apidae (Bombini): Bombus pensylvanica sn cp fq; Anthophoridae (Ceratinini): Ceratina dupla dupla sn cp fq; Anthophoridae (Eucerini): Synhalonia speciosa sn cp; Megachilidae (Megachilini): Megachile brevis brevis sn, Megachile montivaga fq, Megachile policaris sn; Megachilidae (Osmiini): Hoplitis pilosifrons cp

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon virescens cp np fq, Augochlorella striata cp np fq, Halictus confusus cp np, Halictus ligatus cp np, Halictus parallelus cp np, Halictus rubicunda cp np, Lasioglossum albipennis cp np, Lasioglossum oenotherae cp olg (MH), Lasioglossum pectoralis cp np, Lasioglossum versatus cp np

Flies
Syrphidae: Eristalis dimidiatus fp np, Eristalis stipator fp np, Eupeodes americanus fp np, Sphaerophoria contiqua fp np, Tropidia mamillata fp np; Tachinidae: Gymnoclytia immaculata fp np

Butterflies
Papilionidae: Battus philenor sn; Pieridae: Pontia protodice sn

Skippers
Hesperiidae: Polites peckius sn, Polites themistocles sn

Beetles
Chrysomelidae: Diabrotica undecimpunctata fp np; Curculionidae: Odontocorynus scutellum-album fp np fq

The flowers are pollinated primarily by long-tongued bees, butterflies, and skippers. Halictid bees and Syrphid flies often visit the flowers, but they are attracted by the abundant pollen and cannot be considered very effective at pollination. Among the long-tongued bees, are such visitors as Little Carpenter bees and large Leaf-Cutting bees, which suck nectar or collect pollen. The foliage is eaten occasionally by rabbits, and probably other mammalian herbivores.

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: NNR - Unranked

Rounded Global Status Rank: G5 - Secure

The preference is full sun, moist conditions, and a loamy soil with high organic content. This plant develops quickly during the spring and flowers readily. Later in the year, it becomes dormant and less attractive in appearance, but can tolerate some drought. This plant is easy to grow if it is not too dry, and can spread aggressively.