This largely Appalachian taxon of relatively wet sites is close to var. rudgei and has been combined in FNA 23 and other treatments, but W has maintained it as a species. Further analysis is needed. Both var. debilis and var. rudgei may have some pubescence on perigynia (FNA 23). A more distinctive character of var. pubera is reported to be the generally short-awned scales (and perhaps reddish-brown margins).