This is widespread in eastern states, with a range centered between palmata and riparia. Some colls. are difficult to distinguish from palmata, riparia, baileyana or aestivalis, and the potential for hybridization needs investigation; 2n = 38 in all (?) of these species. Distinctive features of vulpina include: leaves moderately large and rotund (ca. 5-15 x 5-15 cm) with relatively shallow lobes and blunt teeth; mature branchlets usually subterete, grayish or brownish (but often purplish when young), with diaphragms only ca. 1-3 mm thick.