Trumpet Evening Primrose

Oenothera jamesii

Other common name(s):

Trumpet Evening-primrose, River Primrose

Family:

Onagraceae (Evening Primrose Family)

Plant Ecoregion Distribution Map

This map uses data from the US EPA. EPA ย servers have been offline frequently so maps may not display. We are working on a solution.

Edwards Plateau, High Plains, Southwestern Tablelands, Texas Blackland Prairies
Balcones Canyonlands
Canadian/Cimarron High Plains
Canadian/Cimarron Breaks, Flat Tablelands and Valleys
Floodplains and Low Terraces1, Northern Blackland Prairie, Southern Blackland Prairie

Plant Characteristics

Growth Form

Herbaceous

Height

4
to
6
ft.

Spread

2
to
3
ft.

Leaf Retention

Deciduous

Lifespan

Biennial

Habitat and Care Requirements

Soil Type(s)

Loam, Moist, Rich, Sand, Well Drained

Light Requirement

Sun

Water Requirement

Medium, High

Native Habitat

Disturbed Areas, Riparian, Wetland

Bloom and Attraction

Bloom Color

Yellow

Bloom Season

Summer, Fall

Seasonal Interest

Fruit, Nectar, Pollen

Wildlife Benefit

Bees, Birds, Butterflies, Moths, Nectar Insects

Maintenance

Requires consistently moist soil; do not let dry out between waterings. But roots can also rot with too much water. As a pioneer species, it often grows in disturbed soils, contributing to soil stabilization. Flowers open late afternoon or early evening, making it a great addition to a night-time pollinator garden. This is a relatively tall plant, so a location in the back of a bed is appropriate. Aphids and spider mites are the most common pests that can affect the plant. Additionally, certain fungal diseases can pose a threat, particularly in overly moist conditions. Native habitat: stream banks, wet places.

Description

Blooms July-October. Features branching stems with linear to lanceolate leaves that grow up to 4 inches long. The leaves have a soft texture, with fine hairs. Large trumpet shape flowers have petals that can grow as wide as 4 inches. The fruit is a capsule.

About the Region

Fall Symposium 2025 Logo - Teach for the Future

Salado, the location of our Fall 2025 Symposium, lies at the intersection of two ecoregions: the Edwards Plateau (Limestone Cut Plain) and Blackland Prairie (Northern Blackland Prairie).

The Edwards Plateau area is also called the Hill Country; however, this general term covers a much larger area extending farther north. Spring-fed creeks are found throughout the region; deep limestone canyons, rivers, and lakes (reservoirs) are common. Ashe juniper is perhaps the most common woody species found throughout the region. Additional woody species include various species of oak, with live oak (Quercus fusiformis) being the most common. Sycamores (Platanus occidentalis) and bald cypress (Taxodium distichum) border waterways. This area is well known for its spring wildflower displays, though they may be viewed in spring, late summer, and fall, as well. According to Texas Parks and Wildlife, average annual rainfall in the Edwards Plateau ranges from 15 to 34 inches.

The Blackland Prairie extends from the Red River south to San Antonio, bordered on the west by the Edwards Plateau and the Cross Timbers, and on the east by the Post Oak Savannah. Annual rainfall averages 30 to 40 inches, with higher averages to the east. This region is dominated by prairie species. The most common grass species include little bluestem (Schizachyrium scoparium) and Indian grass (Sorghastrum nutans) in the uplands and switchgrass (Panicum virgatum) in the riparian areas and drainages. Common herbaceous flowering plants include salvias, penstemons, and silphiums. This area has suffered greatly from overgrazing and agricultural use. Few intact areas remain, though many of the plants can be found along county roadsides throughout the region.

Our fall Symposium host chapter, the Tonkawa Chapter, includes both of these ecoregions.

Source: Wildflowers of Texasย by Michael Eason