Poa macrantha, commonly known as Seashore Bluegrass or Large-flowered Sand Dune Bluegrass, is a perennial grass that is native to coastal dune systems and sandy shores along the west coast of North America, from Alaska to northern California. It is well-adapted to its native habitat, which includes open sandy beaches and the foredunes of coastal dune ecosystems. This grass typically forms loose clumps and can reach up to 24 inches in height. It has a robust root system with very long, stout rhizomes and stolons that can extend up to 13 feet, which help stabilize the shifting sands of its native dune habitats.

Seashore Bluegrass is valued for its ability to prevent soil erosion and stabilize dunes, making it an important species for coastal restoration projects. It has a dioecious reproductive system, meaning male and female flowers are found on separate plants. The grass is not particularly showy, but it is crucial for the ecological health of coastal systems. In cultivation, it requires well-drained sandy soils and full sun exposure to thrive. It is relatively low-maintenance, needing minimal water once established. Seashore Bluegrass is not commonly used in ornamental gardening but is sought after for habitat restoration and erosion control due to its extensive rhizome network.CC BY-SA 4.0