Flora of North America species comparison

Carex canescens subsp. disjuncta is a dominating subspecies in the southern part of the range of the species in eastern North America; it grades into subsp. canescens in northern areas. Subspecies disjuncta differs from subsp. canescens in its longer culms (to 90 cm), leaves, inflorescences [1–12(–15) cm], and spikes. The subglobular spikes are often more numerous and the proximal separated by 2–5 cm. The perigynia are slightly longer, clearly wider and more abruptly beaked than in the type subspecies.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Carex canescens subsp. canescens is a variable taxon with a wide circumpolar distribution; it is found throughout the distibution range of the species, except the southernmost parts of southeastern United States. Many varieties and forms have been described in the subspecies. Slender, short plants with subglobose spikes and small, short-beaked perigynia have often been called var. subloliacea. Those plants represent both subspecies treated herein and to a minor part also C. lapponica. Tall, robust plants with stout, relative dark perigynia from mountainous regions (especially British Columbia and Alaska) may represent an ecotype and are often called var. robustior. Similar specimens have been collected from southern South America (Tierra del Fuego, Falkland Islands). The status of the taxon needs further study.

(Discussion copyrighted by Flora of North America; reprinted with permission.)