Botanical atlas

Eelgrass

Zostera marina

Eelgrass holds a rare place in human history as the only marine flowering plant ever harvested as a grain. The Seri people of the Gulf of California gathered its ripe seed heads each spring, a wild cereal they called xnois, threshing and grinding it much like wheat or corn. Along other cold coastlines, from the Pacific Northwest to Scandinavia and Iceland, communities pulled the long dried blades from the tideline to stuff mattresses, insulate walls, thatch roofs, and pack fish for market. It was never a medicine chest herb, but a quiet, practical gift from the sea that fed, warmed, and sheltered coastal people for generations.

Safety.

Eelgrass is not documented as toxic, but it is not eaten since submerged marine plants can concentrate pollutants and bacteria from the water. Anyone with a shellfish or marine allergy should be extra cautious around harvested marine plants.