40 ROSACEA. /^. us . 



119. Pyrus rivularis, Dougl. 



Oregon Crab Apple. 



Coast of Alaska, southward along the coast and islands of British 

 Columbia, through Washington and Oregon, west of the Cascade Moun- 

 tains, to northern California. 



A small tree, sometimes 9 metres in height, with a trunk 0.30 to 0.45 

 metre in diameter ; low, rich woods, generally along streams, often form- 

 ing dense thickets. 



"Wood heavy, hard, very close-grained, liable to check badly in drying, 

 susceptible of a beautiful polish ; medullary rays numerous, obscure ; 

 color light brown tinged with red, the sap-wood lighter ; used for mallets," 

 maids, bearings of machinery, etc. 



120. Pyrus Americana, DC. 

 Mountain-ash. 



Labrador, Newfoundland. Antieosti Island, and westward alone the 

 southern shore of James Bay to the valley of the Nelson River, south- 

 ward through all the elevated regions of the northeastern States, and 

 along the high mountains of Virginia and North Carolina ; in northern 

 Michigan, northern Wisconsin, and northern Minnesota. 



A small tree, 6 to 9 metres in height, with a trunk 0.30 to 0.45 metre 

 in diameter ; borders of swamps and moist, rocky woods, reaching its 

 greatest development on the northern shores of Lakes Huron and 

 Superior. 



Wood light, soft, close-grained, compact; medullary rays numerous, 

 obscure ; color light brown, the sap-wood lighter. 



121. Pyrus sambucifolia, Cham. & Schlecht. 

 Mountain-ash. 



Labrador to northern New England and the shores of Lake Superior ; 

 high mountain ranges of the Pacific region from Alaska to southern New 

 Mexico ; in Kamtschatka. 



A small tree, 9 to 12 metres in height, with a trunk sometimes 0.80 

 untie in diameter, or in the Pacific forests generally reduced to a low 

 shrub: cold, wet swamps or borders of streams, reaching its greatest 

 development in northern New England and Minnesota. 



Wood light, soft, weak, close-grained, compact; medullary rays nu- 

 merous, obscure; color light brown, the sap-wood nearly white. 



The astringent bark and unripe fruit of the American mountain ashi s, 

 like those of the nearly allied P. aucuparia of Europe, are extremely 

 astringent, and occasionally used, domestically, in infusions, decoctions, 

 etc., in the treatment of diarrhoea. 



