554 TREES OF NORTH AMERICA 



thick midrib deeply grooved on the upper side, and obscure primary veins; persistent until 

 the end of their second summer; petioles broad, about f ' in length; stipules nearly trian- 

 gular. Flowers solitary, sessile in the axils of the clustered leaves, f ' long; calyx hoary- 

 tomentose. Fruit: mature calyx-tube almost \' long, nearly cylindric, rather larger above 

 than below, 10-ribbed, obscurely 10-angled, slightly cleft at apex, hoary-tomentose; akene 

 pointed at the ends, obscurely angled, chestnut-brown, \' long, covered with long pale or 

 tawny hairs; style 2'-3' in length, generally contracted by 1 or 2 partial corkscrew twists. 

 A resinous slightly aromatic tree, occasionally 40 high, with a short trunk sometimes 

 2^ in diameter, stout spreading usually contorted branches forming a round compact 

 head, and red-brown branchlets coated at first with pale pubescence, soon becoming gla- 

 brous, frequently covered with a glaucous bloom, silver gray or dark brown in their second 

 year, and for many years marked by the conspicuous elevated leaf-scars. Bark red-brown, 

 divided by deep broad furrows, and broken on the surface into thin persistent plate-like 



\ 



Fig. 510 



scales, becoming on old trunks 1' thick. Wood bright clear red or rich dark brown, with 

 thin yellow sap wood of 15-20 layers of annual growth. 



Distribution. Dry gravelly arid slopes at altitudes of 5000-9000; mountain ranges of 

 the interior region of the United States from eastern Washington and Oregon, to lower 

 Green and Snake River valleys, Wyoming, and through Utah and Nevada to south- 

 western Colorado; in California to the eastern slope of the Sierra Nevada, the northern 

 slopes of the San Bernardino Mountains, on Mt. Pinos, San Diego County, and on the 

 northern coast mountains (Snow Mountain to Scott Mountain, Jepson). 



5. Cercocarpus paucidentatus Britt 



Cercocarpus eximius Rydb. 



Leaves oblong-obovate to narrow-elliptic,, acute or rounded and often apiculate at apex, 

 gradually narrowed from above the middle and acute at base, their margins revolute, often 

 undulate, and entire or dentate toward the apex with few small straight or incurved apicu- 

 late teeth, when they unfold coated with hoary tomentum, and at maturity thick, gray- 

 green and covered with soft white hairs or nearly glabrous on the upper surface, pale and 

 tomentulose on the lower surface, '-1' long and \'-?' wide, with a thin prominent midrib 

 and primary veins; petioles stout, tomentose, ultimately pubescent or nearly glabrous, 

 iV-i' in length; stipules linear-lanceolate, tomentose, about half as long as the petioles. 

 Flowers appearing from March to May and often again in August, nearly sessile, solitary, 



