Calamagrostis canadensis

Calamagrostis canadensis is a wide-ranging perennial grass with a circumboreal distribution and occurring throughout North America, including Canada, Greenland, and the United States, northern Asia, Russia, and northern Europe. There are many forms, varieties, and subspecies described which are likely apomictic clones, and subspecific recognition needs additional research. Little is known about threats or trends, but with a large range extent and number of occurrences, abundant habitat, and broad habitat preferences, this species is considered secure.

Calamagrostis canadensis has a circumboreal distribution and occurs throughout North America, including Canada, Greenland, and the United States with a southern limit in western North Carolina, eastern Tennessee, and northeast Georgia in the southeastern United States and New Mexico, Arizona, and California in the southwestern United States, northern Asia to northeastern China and Japan, Russia, and scattered populations in northern Europe (FNA 2007). There are many forms, varieties, and subspecies described which are likely apomictic clones (FNA 2007).

By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024, it is estimated that there are over 4,000 occurrences rangewide (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).

Although threats are not widely documented, Calamagrostis canadensis is potentially threatened by development, recreation, invasive species, and other threats in some places; land-use conversion and habitat fragmentation are low-level threats to this species (Southern Appalachian Species Viability Project 2002). However, their overall impact is likely negligible given the species' broad range and large number of occurrences.