Oenothera villosa

Oenothera villosa is a wide-ranging biennial herb in a variety of open habitats, often with disturbance, natively occurring from southern British Columbia in Canada south to California and east through the Rocky Mountain and Great Plains regions, and eastern areas of North America are likely naturalized in the past several hundred years. There are two subspecies: ssp. strigosa is western and has not spread much outside its native range; ssp. villosa is found from the eastern foothills of the Rocky Mountains eastward throughout the Great Plains region and has spread to eastern North America with introductions in southern South America, Europe, Asia, and southern Africa. Threats include development, rights-of-way maintenance activities, and invasive species. Little is known about trends, but with a large range extent and large number of occurrences, abundant habitat, broad habitat preferences, and no obvious intrinsic vulnerabilities, this species is considered secure.

Oenothera villosa natively occurs from southern British Columbia in Canada south to California and east through the Rocky Mountain and Great Plains regions, and eastern areas of North America are likely naturalized in the past several hundred years (FNA 2019, Weakley and the Southeastern Flora Team 2024). There are two subspecies: ssp. strigosa "occurs primarily in the Pacific Northwest southeast through the Rocky Mountains" and has not spread much outside its native range; ssp. villosa "is found primarily from the eastern foothills of the Rocky Mountains eastward throughout the Great Plains region" and has spread to eastern North America with introductions in southern South America, Europe, Asia, and southern Africa (FNA 2019).

By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024, it is estimated that there are over 1,000 occurrences rangewide (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).

Although threats are not widely documented, this species is potentially threatened by development, rights-of-way maintenance activities, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, tolerance of light disturbance, and affinity for typically abundant habitats, as well as no obvious intrinsic vulnerabilities.