Glyceria canadensis aka Rattlesnake Grass

Glyceria canadensis is a grass in the Poaceae family. It is perennial, which means it lives beyond one season. Its common names include rattlesnake mannagrass and rattlesnake grass. It grows wild in Canada and parts of the United States. Its US range includes the north and east-central parts. Chicago Botanic Garden names it as a Midwest native too. Kew places it in the temperate climate zone. The Royal Horticultural Society does not list it as native to Britain or Ireland.

Chicago Botanic Garden says this grass has an upright form. The records give no height or width for the full-grown plant. They give no leaf or stem details for this species. The RHS page notes spreading roots and narrow leaves for the genus. Those traits do not tell us this species has them. A garden plan thus needs a separate size source for this species. The records show an upright grass that lives beyond one season. They do not give its exact size.

Chicago Botanic Garden lists green and purple flowers. It gives bloom times of May through June and July through August. This puts bloom from late spring into summer. Local growing conditions may affect the show of blooms. The source gives no bloom times for each region. It gives no further details on this species' flower clusters. Nor does it describe fruits, seeds, or pollination, the transfer of pollen. The RHS account of the genus cannot fill these gaps.

Chicago Botanic Garden lists full sun or partial shade for growth. It calls for moist soil and USDA hardiness zones 3–8. These give the clearest guides to a site for this species. The records do not say which soil texture it prefers. They give no preferred soil pH, or acid level. They do not confirm it can cope with drought or standing water. Listed garden uses include beds and borders. The records note its upright form and green-to-purple blooms for these uses.

The records do not say how hard care is. Nor do they rate how fast the grass grows. They name no pests, diseases, or other repeat garden problems. They give no proof of edible parts or uses as medicine for this species. They include no safety check for people or pets. These gaps do not mean the plant is safe or harmful. Whether it is safe to eat or toxic remains unknown.