82 SILVA OF NORTH AMERICA. ROSACER. 
northeastern Asia’ and the Kurile Islands* to Japan,’ extending south in western America along all 
the mountain ranges of the interior* and western part of the continent to southern New Mexico, and 
to the neighborhood of the Yosemite valley in central California.> It inhabits the margins of cold wet 
alpine swamps and the borders of streams, and probably attains its greatest size in northern New 
England, where it grows at higher elevations above the level of the sea than Pyrus Americana, and 
in the region immediately north and west of Lake Superior. 
The wood of Pyrus sambucifolia is close-grained but soft, light, and weak; it is light brown, with 
thin lighter colored sapwood and obscure medullary rays. The specific gravity of the absolutely dry 
wood is 0.5928, a cubic foot weighing 36.94 pounds. 
Pyrus sambucifolia was first distinguished by the French botanist Michaux, who found it in 
Canada late in the last century. In cultivation it has been usually confounded with Pyrus Americana, 
from which it is best distinguished by its smaller cymes, its larger and later flowers and much larger 
fruit, and its usually more obtuse and broader leaflets. The large and brilliant fruit of this tree makes 
it the handsomest of all the Mountain Ashes, and it is a common ornament of gardens in northern 
Vermont and New Hampshire and in northern Michigan, Wisconsin, and Minnesota, where it often 
grows to a large size and during the autumn and early winter is a conspicuous and beautiful object. 
1 Trautvetter & Meyer, Fl. Ochot. 37. — Maximowicz, Prim. Fl. occidentalis, Watson, Proc. Am. Acad. xxiii. 263 [Sorbus occidentalis, 
Amur. 103. 
2 Miyabe, Mem. Bost. Soc. Nat. Hist. iv. 232 (Fl. Kurile Islands). 
8 Franchet & Savatier, Enum. Pl. Jap. i. 140.— Maximowicz, 
Bull. Acad. Sci. St. Pétersbourg, xix. 174 (Mel. Biol. ix. 171). 
4 Coulter, Man. Rocky Mt. Bot. 89. 
5 The subalpine form of the high mountains of Washington, 
Oregon, and California, a low shrub with small cymes and with 
leaves composed of seven to eleven oblong or elliptic-obovate leaf- 
lets usually serrate only towards the apex, has been regarded as a 
distinct species (Sorbus pumila, Rafinesque, Med. Fi. ii. 265. — Pyrus 
Greene, Fl. Francis. i. 54]), but intermediate forms appear to con- 
nect it with the northern and eastern tree, and it is perhaps better 
to consider it a variety of that species (var. pumila) until the 
American Mountain Ashes, which should perhaps be considered 
geographical varieties of one widely distributed species, are better 
understood than they are at present. 
6 Pyrus sambucifolia requires a northern climate with long cold 
winters to develop all its beauties, and it does not flourish even in 
eastern New England, where it is a less beautiful plant than the 
Old World Mountain Ash. 
EXPLANATION OF THE PLATES. 
Puate CLXXIII. Pyrus sampBucirorta. 
1. A flowering branch, ‘natural size. 
2. Vertical section of a flower, enlarged. 
3. An ovary divided transversely, enlarged. 
4. Portion of a young branch showing stipules, natural size. 
Puate CLXXIV. Pyrvus sAMBUCIFOLIA. 
1. A fruiting branch, natural size. 
2. Vertical section of a fruit, enlarged. 
3. Cross section of a fruit, enlarged. 
4. Vertical section of a seed, enlarged. 
5. An embryo, much magnified. 
6. Winter-buds, natural size. 
