Habitat and Range.—Mountain slopes, cool woods, along the shores of rivers and ponds, often associated with P. Americana, but climbing higher up the mountains.
From Labrador and Nova Scotia west to the Rocky mountains, then northward along the mountain ranges to Alaska.
Maine,—abundant in Aroostook county, Piscataquis county, Somerset county at least north to the Moose river, along the boundary mountains, about the Rangeley lakes and locally on Mount Desert Island; New Hampshire,—in the White mountain region; Vermont,—Mt. Mansfield, Willoughby mountain (Pringle); undoubtedly in other sections of these states; to be looked for along the edges of deep, cool swamps and at considerable elevations.
South of New England, probably only as an escape from cultivation; west through the northern tier of states to the Rocky mountains, thence northward along the mountain ranges to Alaska and south to New Mexico and California.
Habit.—A shrub 3-10 feet high, or small tree rising to a height of 15-25 feet, reaching its maximum in northern New England, where it occasionally attains a height of 30-35 feet, with a trunk diameter of 15 inches. It forms an open, wide-spreading, pyramidal or roundish head, resembling the preceding species in the color of bark, in foliage and fruit. Whether these are two distinct species is at the present problematical, as there are many intermediate forms, and the same tree sometimes furnishes specimens that would indubitably be referred to different species.
Bark.—On old trees light brown and roughish on the trunk, separating into small scales curling up on one side; large limbs light-colored, smoothish, often conspicuously marked with coarse horizontal blotches and leaf-scars; season's shoots light brown, smooth, silvery dotted.
Winter Buds and Leaves.—Terminal bud 1 inch long, lateral ½ inch, appressed, brownish, scythe-shaped, acute, more or less glutinous. Leaves pinnately compound, alternate, stems grooved and reddish above, enlarged at base; stipules deciduous; leaflets 7-15, the odd one stalked, 1-3 inches long, ½-1 inch wide, bright green above, paler beneath, smooth, mostly ovate-oblong, serrate above the base; apex rounded or more usually tapering suddenly to a short point, or rarely acuminate; base inequilateral.
Inflorescence.—In broad, compound cymes at the ends of the branches; flowers white and rather larger than those of P. Americanus; calyx 5-lobed; petals 5, ovate, short-clawed; stamens numerous; pistil 3-styled.
Fruit.—In broad cymes; berries bright red, roundish, rather larger than those of P. Americana, holding on till winter.
Horticultural Value.—Hardy in New England, though of shrub-like proportions in the southern sections; grows in exposed situations inland, and along the seashore. The dwarf habit, graceful foliage, and showy fruit give it an especial value in artificial plantations; but it is seldom for sale in nurseries and only occasionally by collectors. It is readily transplanted and is propagated by seed.