• Double O Arch

    Arches

    National Park Utah

There are park alerts in effect.
show Alerts »
  • Delicate Arch Viewpoint Inaccessible

    Wolfe Ranch and the hiking trail to Delicate Arch are open, but flood waters and mud have blocked the road to Delicate Arch Viewpoint.

  • Safety in Bear Country

    Black bears have been seen near Devils Garden Campground. Don't lure or feed them. Dispose of trash in designated receptacles; don't leave it in bags or other soft containers. Store food in vehicles or hard containers when not being prepared or consumed. More »

Bridges Evening-primrose (Tall Yellow Evening-primrose)

Oenothera longissima

Oenothera longissima

Family: Onagraceae (Evening-primrose Family)

Perennial or biennial herbs; stems 7.9” to 5.9' (2 to 18 dm) tall or more

Leaves: alternate and basal; simple; can be toothed; 0.8” to 14” (2 to 35 cm) long, 0.12” to 1.8” (0.3 to 4.5 cm) wide

Flowers: 4 yellow petals; 4 sepals; 8 stamens; 4 lobed stigma; bisexual; usually radially symmetrical; fragrant; 1” to 2” (2.5 to 5 cm) long

Pollinators: other Oenothera species are pollinated by bees, moths and butterflies

Fruits: 4 chambered capsule

Blooms in Arches National Park: April, May, June, July, August, September, October

Habitat in Arches National Park: disturbed areas, riparian areas and hanging garden communities

Location seen: lower and upper Courthouse wash

Other: The genus name, “Oenothera”, means “wine-scented” and refers to the use of the roots in winemaking. The species name, “longissima”, refers to the long corolla tube or hypanthium.

The type specimen was collected in 1911 in Natural Bridges National Monument in southeast Utah which is where one of the common names comes from.

Did You Know?

Ed Abbey

Edward Abbey worked as a seasonal park ranger at Arches in the late 1950s. His 1968 memoir of this experience, "Desert Solitaire," has become a classic of desert literature.