546 



TREES OF NORTH AMERICA 



deeply divided into lateral lobes, or occasionally 3-Iobed, 3'-4' long, and 2'-3' wide. Flow- 

 ers i'- T V in diameter, on long slender glabrous pedicels, in broad glabrous corymbs, with 

 linear caducous bracts and bractlets; calyx-tube broadly obconic, glabrous, the lobes grad- 

 ually narrowed from a broad base, entire or occasionally minutely dentate, acute and bright 

 red at apex, glabrous on the outer surface, villose on the inner surface; stamens 10 or rarely 

 5 by abortion; anthers small, pale rose color; styles 2-5, surrounded at base by tufts of long 

 pale hairs. Fruit ripening and falling in August and September, on slender pedicels, in 

 compact, many-fruited drooping clusters, short-oblong, truncate at apex, black and lus- 

 trous, very rarely chestnut-colored (f. badia Sarg.), about \' long; calyx persistent; flesh 

 thick, sweet and succulent, light yellow; nutlets usually 5, about \' long, narrowed at base, 

 broad and rounded at apex, ridged on the back with a narrow ridge, the ventral cavities 

 irregular, small and shallow. 



A tree, 30-40 high, with a long trunk 18'-20' in diameter, stout branches spreading and 

 ascending and forming a compact round-topped head, and slender rigid glabrous bright red 



Fig. 502 



or orange-red lustrous branchlets unarmed, or armed with straight or slightly curved blunt 

 or rarely acute bright red ultimately ashy gray spines \'-V long; often shrubby and spread- 

 ing into wide thickets. 



Distribution. Banks of mountain streams; valley of the Parsnip River, British Columbia, 

 through Washington and Oregon to the valley of the Pitt River, California, and eastward 

 in the United States through the northern Rocky Mountain region to the Bighorn Moun- 

 tains, Wyoming; passing into the var. Suksdorfii Sarg. differing in its 20 stamens, fruit 

 not more than \' in diameter, usually in few-fruited clusters and ripening from the 1st of 

 July to the middle of August. A shrub with numerous stems occasionally 25 high; banks 

 of the Columbia River and borders of bottom-lands, western Klickitat County, Washington. 



151. Crataegus rivularis Nutt. 



Leaves lanceolate to narrowly oblong-obovate or elliptic, acute, acuminate or abruptly 

 acuminate at apex, gradually narrowed and concave-cuneate at the long entire base, and 

 very finely crenately serrate above with glandular teeth, when they unfold tinged with red, 

 villose above and coated below with matted pale hairs, more than half grown when the 

 flowers open late in May and then hairy on the midrib and veins above and pale and gla- 

 brous below, and at maturity thin, dull bluish green and smooth on the upper surface, pale 

 yellow-green on the lower surface, about 2' long and f ' wide, with a slender yellow midrib 

 and 3 or 4 pairs of thin obscure primary veins; petioles slender, slightly w r inged at apex, at 



