Lawrence’s milkvetch – State Wildlife Action Plan

Lawrence’s milkvetch

Photo Credit: Oregon Department of Agriculture

Lawrence’s milkvetch is a taprooted perennial 20-40 cm high. Stems are clustered, erect or decumbent at the base, and canescent with short crisped pubescence. Leaves are 3-5 cm long, with short petioles. Leaflets number 11-17, are linear to cuneate with obtuse or emarginate apices, 0.6-1.0 cm long, and woolly pubescent. Many-flowered racemes are borne on peduncles much longer than the leaves. The calyx is about 1.0 cm long and woolly pubescent, the pubescence mostly whitish with scattered dark hairs. The corolla is cream or yellowish, about 1.5 cm long. The pods are obliquely ovate-oblong and lunately incurved, the stipe 0.5-1.5 cm long, the body 0.8-1.5 cm long, moderately compressed, and villous (or glabrous in some variant populations*) with prominent sutures, the valves becoming leathery and impressed-reticulate.

Overview

  • Species Common Name Lawrence's milkvetch
  • Species Scientific Name Astragalus collinus var. laurentii
  • Federal Listing Status Species of Concern
  • State Listing Status Threatened

Ecoregions

    Special needs

    Lawrence’s milkvetch is found on deep loess soils in Palouse grasslands. Occupies dry, grassy hills and hilltops.

    Limiting factors

    This narrowly-distributed species’ is endemic to the Columbia Plateau, including western Umatilla and Morrow Counties. Habitat loss, namely agricultural conversion, has impacted Lawrence’s milkvetch. Grazing, herbicide use, road construction, and invasive plants (primarily knapweeds) are additional risk factors.

    Data gaps

    Improve understanding of reproductive biology. Conduct pollinator studies. Refine seed germination, propagation, and transplanting protocols.

    Conservation actions

    Work cooperatively with landowners to protect and maintain priority sites. Control invasive plants.