Home

Yellow Evening Primrose (4)

All the yellow evening primroses shown here have large, showy flowers with four sepals, four petals, eight stamens and a stigma divided into four parts. They open late in the day and close the next morning, withering and turning orange. Growth habit and hairiness differentiates the species.

Oenothera elata

Hooker's Evening Primrose
Oenothera elata ssp. hirsutissima (O. hookeri)

Family: Evening Primrose (Onagreaceae)
AKA: Western Evening Primrose, Tall Evening Primrose
Photo taken on: September 2, 2020
Location: East River, Almont, CO
Life Zones: Foothills and montane
Habitat: Disturbed moist areas, roadsides

Plant grows from 16" to 100" tall, usually 18" to 36" in this area, with multiple stems from the base. Flowers are up to 3" across. Flower tubes up to 2" long. Leaves are grayish-green.

Flora of North America reference.

Yellow Evening Primrose
Oenothera flava

Family: Evening Primrose (Onagreaceae)
AKA: Golden Evening Primrose
Photo taken on: June 19, 2007
Location: SR 135, Almont, CO
Life Zones: Foothills to montane
Habitat: Dry meadows and roadsides

Low growing plant with no stem only a 1" to 6" flower tube. Leaves are long and narrow with wavy edges. Flowers are up to 2" across.

Flora of North America reference.

Longstem Evening Primrose
Oenothera longissima

Family: Evening Primrose (Onagreaceae)
AKA: Bridges Evening Primrose, Tall Yellow Evening Primrose
Photo taken on: August 13, 2012
Location: Abiquiu, NM
Life Zones: Plains and foothills
Habitat: Moist areas, woodlands

Can grow to 9 feet tall in the right conditions with a single, stout, reddish stem. This plant was about 6 feet tall. Leaves are long and willow-like with slightly wavy edges. The flowers are large and showy with a very long flower tube, 4" to 6", which distinguishes it from O. elata and O. villosa. O. elata also is branched and does not grow as tall as O. longissima. O. villosa has more hairs.

Flora of North America reference.

Hairy Evening Primrose
Oenothera villosa

Family: Evening Primrose (Onagreaceae)
AKA:
Photo taken on: August 24, 2020
Location: Rio Chama, Abiquiu, NM
Life Zones: Plains and foothills
Habitat: Moist areas, meadows, forests

Grows to 6 feet tall with a single reddish stem or branches from the base and willow-like leaves. This plant was at least 6 feet tall with a single stem. Stems have long, spreading hairs, usually with tiny red, blisters at their bases. Buds and leaves also have short hairs. The flowers are large and have a 2" flower tube.

Flora of North America reference.

Yellow Single Flowers