ROSACEAE 
Mountain Ash 
Pyrus americana (Marsh.) DC. [Sorbus americana Marsh,] 
HABIT.—A small tree 15-20 feet high, with a trunk diameter 
of not over a foot; branches slender, spreading, forming a nar- 
row, rounded crown. 
LEAVES.—Alternate, compound, 6-9 inches long. Leaflets 
9-17, 2-3 inches long and %-34 inch broad; sessile or nearly so, 
except the terminal; lanceolate to oblong-lanceolate, taper- 
pointed; finely and sharply serrate above the entire base; mem- 
branaceous; glabrous, dark yellow-green above, paler beneath, 
turning clear yellow in autumn. Petioles slender, grooved, en- 
larged at the base. 
FLOWERS.—May-June, after the leaves; perfect; 1% inch 
across; borne on short, stout pedicels in many-flowered, flat 
cymes 3-5 inches across; calyx urn-shaped, 5-lobed, puberulous; 
petals 5, white; stamens numerous; styles 2-3. 
(FRUIT.—October, but persistent on the tree throughout the 
winter; a berry-like pome, subglobose, 14 inch in diameter, bright 
red, with thin, acid flesh; eaten by birds in the absence of other 
food. 
WINTER-BUDS.—Terminal bud about % inch long, ovoid, 
acute, with curved apex; lateral buds ‘smaller, appressed; scales 
rounded on the back, purplish red, more or less pilose above, 
gummy. 
BARK.—Twigs at first red-brown and hairy, becoming 
glabrous, dark brown; thin, light gray-brown on the trunk, 
smooth, or’ slightly roughened on old trees; inner bark fragrant. 
WOOD.—Light, soft, close-grained, weak, pale brown, with 
thick, lighter colored sapwood. 
DISTRIBUTION.—Ludington and northward, principally 
along the shore of L. Michigan, but common throughout the 
Upper Peninsula. 
HABITAT.—Prefers rich, moist soil on river banks and on 
the borders of cold swamps; rocky hillsides and mountains. 
‘NOTES.—More often a shrub. Easily transplanted, but 
slow of growth. One of the most beautiful trees of our northern 
forests. 
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