Maritime Quillwort, Isoetes maritima (Isoetaceae), in the Yukon Territory

Maritime Quillwort, Isoetes maritima (Isoetaceae), is reported from a singl e location in southeastern Yukon Territory and is a new record for the flor a of the Territory. The Yukon I. maritima population is compared to that of I. echinospora, also known from only one Yukon location. Isoetes maritima may have reached here as populations migrating eastward across the Yukon Ri ver watershed from the Beringian glacial refugium before coastal areas of n orthern British Columbia and adjacent southern Alaska had emerged from the Wisconsinan Cordilleran Ice Sheet. If so, isolated I. maritima populations could be expected at floristically diverse aquatic sites elsewhere along th e Yukon River watershed.