350 



TREES OF NORTH AMERICA 



on the lower surface, lA'-3' long, \'-^' wide, with thick conspicuous midribs grooved 

 on the upper side, and numerous thin primary veins connected by reticulate veinlets, 

 deciduous in spring or early summer; their petioles tlnck, ^'^' long. Flo"wer8 

 appearing in June, ^ in diameter, in hoary-tomentose panicles 2'-3' across; petals 

 oblong; inner surface of the disk pilose. Fruit fully grown by the end of August, 

 ^' long, persistent on the branches after opening until the spring of the following 

 year; conspicuous from the contrast of the bright red faded petals and the white 

 silky pubescence of the calyx and carpels; seed y^^' long, and one third as long as 

 its wing. 



A tree, 18-20 high, with a slender often hollow trunk 5'-G' in diameter, rigid 

 upright contorted branches, and slender branchlets at first bright reddish brown 

 and more or less thickly covered with hoary tomentum, becoming light brown or gray 

 in their second year and marked by large elevated leaf-scars; or more often a low 

 shrub. Bark about -^q' thick, dark red-brown, and broken on the surface into small 

 square persistent plate-like scales. Wood very heavy, hard, close-grained, dark 

 rich brown streaked with red, with 14 or 15 layers of annual growth. 



Distribution. Mountain ranges of southern Arizona, Sonora, and Lower Califor- 

 nia; arborescent and of its largest size in Arizona on the Santa Catalina Mountains 

 at elevations of about 5000 above the sea; on the bottoms and rocky sides of gulches, 

 or on grassy slopes. 



2. LYONOTHAMNUS, Gray. 



A tree or shrub, with scaly bark exfoliating in long strips, stout terete pubescent 

 ultimately glabrous branchlets, and scaly buds. Leaves opposite, long-petiolate, 

 lanceolate, acuminate, rounded or wedge-shaped at the base, entire, finely crenulate- 



serrate or serrulate-lobulate below the middle, or sometimes irregularly pinnately 

 parted into 3-8 linear-lanceolate remote lobulate segments, coriaceous, transversely 

 many-veined, dark green above, paler and more or less pubescent below, persistent; 

 stipules lanceolate, acute, minute, caducous. Flowers on slender pedicels, in broad com- 

 pound terminal pubescent cymose corymbs, with minute acute persistent bracts and 

 bractlets; calyx-tube hemispherical, with 1-3 bractlets, tomentose on the outer sur- 

 face, the lobes nearly triangular, slightly keeled, apiculate, persistent; disk 10-lobed. 



