Davis’ peppergrass is a deep-rooted perennial that forms low (4-8 cm tall) clumps. Individual plants produce many, mostly unbranched, stems with a pubescence of simple hairs. The sessile, simple leaves are green, but often appear grayish due to a dusting of the white clay in which they grow. Several dozen or more white, four-petaled flowers typical of the mustard family are produced in each rounded inflorescence. Upon fruiting, these are followed by a crowded cluster of smooth or slightly hairy siliques. Plants typically begin flowering in May and can continue until August, with the peak flowering time and the ability of plants to produce fruit dependent on hydrologic conditions.
Davis’ peppergrass occurs on hard, white clayey playas at elevations from 3100-5600 feet. These poorly-drained areas are often inundated with standing water.
Limiting factors
Off-road vehicles and trampling (due to use of habitat as watering sites for feral and domestic livestock) are among threats to this species. The species is highly vulnerable to climate change because of predicted shifts in precipitation and restricted habitat availability.
Data gaps
Improve understanding of life history and reproductive biology. Analyze differences (observed morphological differences) between isolated populations. Develop propagation and transplanting protocols.
Conservation actions
Fence populations on public land to reduce impacts from off-road vehicles and grazing. Complete conservation status survey’s of Oregon’s populations. Survey potential habitat for additional populations.
