Local Introgression Between Viola cucullata Ait. and V. septentrionalis Greene

Two commonly found, stemless 1 blue violets in New England are Viola cucullata Ait. and V. septentrionalis Greene. Both grow in essentially northern forest habitats, V. cucullata in wet soil beside cold springs, bogs, or woodland streams, and V. septentrionalis in drier locations, usually beneath conifers. Where found, both species may be abundant, but tend to grow as scattered plants rather than in' dense clonal clusters, as is often true of such related species as V. sororia and V. papilionacea. Though their habitats are usually not contiguous, populations of the two species are frequently found side by side, due to disturbance. This is particularly true along creeks running through partly logged or grazed hemlock woods. In these locations V. cucullata occurs on the wet sand or mud at the water's edge and V. septentrionalis on the drier creek bank and in the hemlock forest. V. cucullata has been collected from Newfoundland to the Thunder Bay District of Ontario, and south along the uplands to Minnesota and Georgia. V. septentrionalis has a somewhat similar distribution, occurring from Newfoundland to southern British Columbia and south to Tennessee in the mountains (Fernald, 1950). The ranges of the two species overlap greatly with each other, and also coincide, at least in part, with the ranges of distribution of a number of other species of the Subsection Boreali-Arnericanae