558 



TREES OF NORTH AMERICA 



ground into stout almost horizontal branches, and glabrous or pubescent bright red more or 

 less spinescent branchlets marked by occasional minute pale lenticels, becoming darker red 

 or purple in their second year, and ultimately dark brown or ashy gray; or often a bush, 

 with stout ascending stems 10-12 tall, or a low much-branched shrub. Whiter-buds 

 acute, y long, with chestnut-brown scales, scarious on the margins, those of the inner rows 



Fig. 512 



J' long at maturity, oblong, acute, and generally bright red. Bark about -J-' thick, 

 gray-brown, deeply fissured, and divided into long thick plates broken on the surface into 

 minute persistent scales. Wood heavy, hard, close-grained, pale brown, with thin lighter 

 colored sapwood of 5 or 6 layers of annual growth. 



Distribution. Dry rocky hills and open woods usually in the neighborhood of streams, 

 sometimes forming thickets of considerable extent; central Oregon to northeastern Cali- 

 fornia in the region east of the Cascade and Sierra Nevada Mountains, and common to cen- 

 tral California; on the foothills of the western slopes of the Sierra Nevada up to altitudes of 

 4000 south to the Yosemite Valley, and on the coast ranges to Black Mountain, Santa 

 Clara County; of its largest size on the borders of small streams in southern Oregon and 

 northern California; at high altitudes, and in the arid regions of southeastern Oregon a low 

 shrub producing sparingly small sometimes pubescent fruit (var. oregona Wight) ; Klamath 

 Indian Reservation, near Klamath Falls and in Sprague River Valley, Klamath County. 



2. Prunus umbellata Ell. Sloe. Black Sloe. 



Leaves obovate-lanceolate to oblong, acute at the ends or sometimes rounded or slightly 

 cordate at base, finely and sharply serrate with remote incurved glandular teeth, and usu- 

 ally furnished with 2 large dark glands at the base, when they unfold bright bronze-green, 

 with red margins, midrib, and petiole, glabrous above and pubescent or glabrous below 

 with the exception of a few hairs along the prominent orange-colored midrib and primary 

 veins, and at naturity thin, dark green above, paler below, 2'-2|' long and l'-H' wide, 

 petioles stout, glabrous or pubescent, about \' in length; stipules lanceolate, setaceous, 

 glandular-serrate, \'-\' long. Flowers opening in March and April before the appearance 

 of the leaves, f ' in diameter, on slender glabrous pedicels |' long, in 3 or 4-flowered umbels; 

 calyx-tube broad-obconic, glabrous or puberulous, the lobes sometimes slightly clavate at 

 the acute red apex, scarious on the margins, and hoary-tomentose on the inner surface; 

 petals nearly orbicular, contracted at the base into a short claw. Fruit ripening from July 

 to September, on slender stems \' to nearly 1' long, globose, without a basal depression, 

 about \' in diameter, with a tough thick black or on some individuals yellow, and on others 

 bright red skin covered with a glaucous bloom, and thick acid flesh; stone flattened with 





