Triglochin maritima, commonly known as Seaside Arrowgrass, is a perennial herb native to coastal salt marshes, brackish marshes, and wetlands across the Northern Hemisphere, including North America, Europe, and Asia. It typically grows up to 30 inches tall and has a grass-like appearance with slender leaves. The greenish flowers, which bloom from May to August, are not particularly showy but are followed by distinctive arrow-shaped seed pods. Seaside Arrowgrass is adapted to saline conditions and can tolerate periodic flooding.

Seaside Arrowgrass is valued for its ability to thrive in saline environments, making it suitable for coastal restoration projects and erosion control. It is also a food source for wildlife, including sheep and deer, despite its potential toxicity, which is usually a result of cyanogenic glycosides that can release cyanide when the plant is stressed, such as during drought. In cultivation, it requires consistently moist or wet soil conditions, full sun to part shade, and can be used as a ground cover in water gardens or naturalized areas.CC BY-SA 4.0