American mountain ash (Sorbus americana)
Small tree, height sometimes 20' to 30', diameter 4" to 12"; spreading, slender branches create a narrow round-topped crown.
Smooth, light gray surface, irregularly broken by small, flat, platelike scales.
Alternate on stem, length about 6" to 8", pinnately compound with 13 to 17 leaflets each 2" to 4" long, pointed and sharply toothed; bright green above, turning bright yellow in fall.
Bright red-orange, rounded berry, diameter about 1/4"; has thin layer of sour flesh; fruit gives tree ornamental appearance.
Found scattered in the woods of northern Minnesota as far south as Pine and Mille Lacs counties; best development in northeastern Minnesota; numerous along edges of swamps; does best in moist locations, thriving fairly well in drier areas and on thinner soils.