White Rock Larkspur – Oregon Conservation Strategy

Photo Credit: Oregon Department of Agriculture

Overview

Species Common Name White Rock Larkspur
Species Scientific Name Delphinium leucophaeum
Federal Listing Status Species of Concern
State Listing Status Endangered

Ecoregions

West Cascades

The West Cascades ecoregion extends from east of the Cascade Mountains summit to the foothills of the Willamette, Umpqua, and Rogue Valleys, and spans the entire length of the state of Oregon. It is largely dominated by conifer forests, moving into alpine parklands and dwarf shrubs at higher elevations.

Willamette Valley

The Willamette Valley ecoregion is bounded on the west by the Coast Range and on the east by the Cascade Range. This long mostly level alluvial plain has some scattered areas of low basalt, and contrasts with productive farmland and large urban areas. It has the fastest-growing human population in the state resulting in challenges due to land-use changes.

Special needs

White rock larkspur occurs in well-drained areas within open lowland prairies, in dry roadside ditches, along river banks and bluffs, and in open areas atop basaltic shelves. This species prefers loose, shallow soils with high organic matter content.

Limiting factors

A key threat to white rock larkspur is habitat loss due to urban and agricultural development. Fire suppression and invasive vegetation encroachment in the understory can degrade remaining habitat. Herbicide use and other roadside maintenance activities can also harm this species. White rock larkspur persists in low numbers in small populations.

Data gaps

Conduct pollinator studies. Investigate hybridization. Develop transplanting protocol.

Conservation actions

Restore habitat using site-appropriate methods: control encroaching trees and shrubs and control key invasive plants.

Key reference or plan

Oregon Department of Agriculture Plant Conservation