518 TREES OF NORTH AMERICA 



A tree, 20-25 high, with a trunk sometimes a foot in diameter, dividing 6-8 

 from the ground into stout almost horizontal branches, and glabrous or pubescent 

 bright red brauchlets 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. 

 Winter-buds acute, ^' long, with chestnut-brown scales, scarious on the margins, 

 those of the inner rows \' long at maturity, oblong, acute, and generally bright red. 

 Bark about ^ 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; southern Oregon to 

 central California in the region west of the Cascade and Sierra Nevada Mountains, 

 and as a low shrub in the Klamath Lake region east of the Cascade Mountains; com- 

 mon in central California and on the foothills of the western slopes of the Sierra 

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

 northern California; at high elevations and in arid regions usually a low shrub pro- 

 ducing sparingly small acid fruit. 



7. Prunus umbellata, Ell. Sloe. Black Sloe. 



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

 slightly cordate at the base, finely and sharply serrate, with remote incurved gland- 

 ular teeth, and usually furnished with 2 large dark glands at the base, when they 



unfold bright bronze-green, with red margins, midribs, and petioles, glabrous above 

 and pubescent or glabrous below with the exception of a few hairs along the promi- 

 nent orange-colored midribs and primary veins, and at maturity membranaceous, 

 dark green above, paler below, 2'-2^' long and !'-!' wide; their petioles stout, 

 glabrous or pubescent, about ' long; stipules lanceolate, setaceous, glandular-ser- 

 rate, j'-f ' long. Flowers opening in March and April before the appearance of the 

 leaves, %' in diameter, on slender glabrous pedicels ^' long, in 3 or 4-flowered 

 umbels; calyx-tube broadly obconic, glabrous or puberulous, the lobes sometimes 

 slightly clavate at the acute red apex, scarious on the margins, and hoary-tomentose 



