Washington's Coast
Washington State Department of Ecology

dune plants
Sandy beach with nearby dune vegetation, Grayland, Washington's southwest coast

Dunes stretch for 60 miles along Washington's southwest coast. The largest dune fields, the Long Beach dunes, extend 19 miles. Dunes can also be found along beaches in Grays Harbor county. Winds whisk sand grains inland to shape dunes. Species adapted to dunes must tolerate wind, sand burial, sand abrasion, salt spray, water deprivation, and salty shifting soils.

Coastal strawberry Coastal strawberry Fragaria chileonsis
A native dune plant. Often found beneath grasses.
Seashore lupine Seashore lupine Lupinus littoralis
A dune meadow plant.
Searocket Searocket Cakile edentula
A tough pioneering annual. Burial in sand stimulates growth.
Beach Morning Glory Beach morning glory Convolvus soldanella
Also called beach bindweed. A native stabilizer.
Beach Pea Beach pea Lathryrus japonicus
A native sand stabilizer.

Parallel ridges
The contours of sand dunes resemble waves running parallel to the ocean. Along Washington's southwest coast, parallel dune ridges extend from Point Grenville to the mouth of the Columbia River. About twenty dune ridges span the Long Beach peninsula.
Only the most tolerant pioneering plants can survive on the foredunes, the ridge closest to the shore. Species adapted to this environment include: European beachgrass, American dunegrass, and American searocket.
Hummocks are small hills inland from the foredune. As sand collects around plants, hummocks form. When the water table rises in the winter, water may fill in around the hummocks.
Deflation plains
As the foredune walls the beach off from inland areas, winds peel sand away from the east side. The sand loss deflates this area down to wet sand. Water-loving plants gather in this zone.
Dune destruction Dune destruction
Dune plants can be destroyed by driving, trampling, and heavy recreational use. Invasive plants such as scotch broom, American beachgrass, and European beachgrass have displaced many native dune plant species.


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