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 T /2- 3 A 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; l /% 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, % inch in diameter, bright 

 red, with thin, acid flesh; eaten by birds in the absence of other 

 food. 



WINTER-BUDS. Terminal bud about V 2 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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