Beckmannia syzigachne aka Slough Grass

Beckmannia syzigachne, or American sloughgrass, belongs to the grass family, Poaceae. It grows as an annual or a short-lived perennial. Its native range spans European Russia and much of temperate Asia. It also reaches subarctic North America and the northern and western United States. It is not native to Britain or Ireland. Wild plants grow in wet meadows, marshes, and swamps. They also grow in ditches and shallow lake margins.

Plants reach about 3.3 feet (1 metre) tall. Their spread reaches about 1.6 feet (0.5 metres). Growth is strong in early summer where shallow water remains. Each flower has both male and female parts. Wind carries the pollen. The source gives two flowering periods: May–June and July–August. It also gives different times for ripe seed. One account places ripening in July–August; another gives September–October. These reports leave the exact season unclear.

This grass suits bog gardens and other wet planting beds. It grows in full sun or light shade. It needs moist or wet soil and tolerates shallow standing water. Sand, loam, and clay can all support it. It also tolerates salt in the soil. Reported soil pH tolerance runs from 5.8 to 7.6. PFAF lists USDA zones 3–8, though its hardiness notes express some doubt. The same source reports successful outdoor growth in Cornwall.

The ripe seeds are edible when cooked and have a mild taste. They can be cooked whole or ground into flour. The flour can go into porridge or flatbreads. Small seeds are easy to gather, but removing their husks takes work. Indigenous peoples in northwestern North America gathered the grain for food. PFAF records no known hazards and no known medicinal uses. That hazard statement does not establish safety for every person or animal.

Ducks, geese, and shorebirds eat the seeds. Muskrats and deer graze the leaves. The grass helps hold soft wetland ground in place. People have also used it to fill bedding and pillows. PFAF does not flag it as weedy. Sow seed on the surface in spring and keep it wet. Seed can germinate fast under these conditions. Spring division offers another way to raise plants.