Leaves broad-obovate to ovate, gradually narrowed below to the cuneate entire base, coarsely serrate above with minute glandular teeth, and often incisely lobed toward the acute apex, nearly fully grown and coated above and on the midrib and veins below with short pale hairs when the flowers open in May, and at maturity thin, glabrous, dark green and lustrous above, paler below, 1′—2′ long, and ½′—1½′ wide; petioles slender, wing-margined above, sparingly glandular, villose early in the season, becoming glabrous, ½′—¾′ in length; leaves at the end of vigorous shoots broad-obovate, incisely lobed at the broad apex, often deeply divided into lateral lobes, or occasionally 3-lobed, 3′—4′ long, and 2′—3′ wide. Flowers ½′—7/12′ in diameter, on long slender glabrous pedicels, in broad glabrous corymbs, with linear caducous bracts and bractlets; calyx-tube broadly obconic, glabrous, the lobes gradually 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 lustrous, very rarely chestnut-colored (f. badia Sarg.), about ½′ long; calyx persistent; flesh thick, sweet and succulent, light yellow; nutlets usually 5, about ¼′ 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 or orange-red lustrous branchlets unarmed, or armed with straight or slightly curved blunt or rarely acute bright red ultimately ashy gray spines ⅓′—1′ long; often shrubby and spreading 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 Mountains, Wyoming; passing into the var. Suksdorfii Sarg. differing in its 20 stamens, fruit not more than ⅓′ 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. [Cratægus 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 glabrous 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 ¾′ wide, with a slender yellow midrib and 3 or 4 pairs of thin obscure primary veins; petioles slender, slightly winged at apex, at first villose, becoming glabrous and rose-colored below the middle, and about ½′ in length; leaves at the end of vigorous shoots often rhombic, coarsely serrate, often slightly incisely lobed, coriaceous, 3′ long, and 2′ wide, with a stout broadly winged petiole. Flowers ½′ in diameter, on long slender pedicels, in rather compact glabrous corymbs; calyx-tube broadly obconic, glabrous, the lobes linear, entire or glandular with minute caducous glands, glabrous on the outer surface, sparingly villose on the inner surface, often tinged with red; stamens 10—20; anthers pale rose color. Fruit ripening in September, on long pedicels, in drooping few-fruited clusters, short-oblong, full and rounded at the ends, dark crimson and marked by many large white dots when fully grown, becoming black and lustrous at maturity, ⅓′—½′ long; calyx slightly enlarged, persistent, with elongated closely appressed entire lobes slightly villose and dark red on the upper side below the middle; flesh thin, yellow, dry and mealy; nutlets 3—5, ¼′ long, narrowed and rounded at the ends, slightly ridged on the back, the ventral cavities broad and shallow.
A tree, occasionally 20° high, with a slender trunk covered with dark brown scaly bark, erect branches forming a narrow rather open head, and slender bright red-brown lustrous branchlets marked by numerous pale lenticels, and unarmed or armed with straight slender spines usually about 1′ long.
Distribution. Banks of mountain streams, often forming thickets; southeastern Idaho, (Pocatello and Inkom, Bannock County); northeastern Nevada (Lee, Elk County) to southwestern Wyoming, eastern Utah, southwestern Colorado, and northern New Mexico.