This occurs mostly in northeastern regions on relatively wet soils. It has been reported from s. Ill., s. Ind., s. Ohio, W.Va., Va. (close to Ky. in some cases) and from Atlantic states south to Flo. (K, W). It is expected in northern and eastern Ky., but has not been confirmed. It has been reported from Ky. by BA and others, but perhaps based only on immature or atypical pumila (M). In FNA 3, D. Bouffard stated: "A few collections of P. pumila from Bourbon, Owen, and Robertson counties, Kentucky, and Macon County, Tennessee, have the black achenes of P. fontana, but without the bosses, and show striations on the younger achenes as in P. pumila" (see also J. Thieret #60416 from GALL). P. fontana is similar to pumila but differs most clearly as follows (FNA 3, W): achenes less elongate, with L/W = 1-1.5 (versus 1.5-2), tuberculate ["conspicuously pebbled or warty with raised bosses"], dark brown to black with pale margins (versus smooth and usually paler brown with raised lines and mottles). Also, petioles of larger leaves are ca. 25-50% as long as blades (versus 33-100%) Blades tend to be smaller, up to 1-7 cm long (versus 2-15 cm), more rounded at base (versus usually cuneate), firmer, less glossy and less translucent (F,).