574 



TREES OF NORTH AMERICA 



slightly recurved flat brown or bright red spines sometimes 1' or more long; leaflets 

 elliptical-oblong, rounded or sometimes slightly emarginate at the mucronate apex 

 wedge-shaped or sometimes rounded at the base, 1^' long and 1' broad, coated at 

 first on the lower surface and on the margins with soft brown hairs, and silvery-pubes- 

 cent on the upper surface, and at maturity thin, pale blue-green, conspicuously retic- 

 ulate-veined, and glabrous with the exception of the slightly puberulous lower side 

 of the slender midribs and stout petiolules; stipels membranaceous, X' long often 

 recurved, sometimes persistent through the season. Flow^ers appearing in May 



1' long, on slender pedicels ^' in length and covered with stout glandular hairs, in 

 short compact many-flowered glandular-hispid long-stemmed racemes; corolla pale 

 rose color or sometimes almost white, with a broad standard and wing-petals. Fruit 

 3'-4' long, about ^' wide, glandular-hispid, with a narrow wing; seeds dark brown, 

 slightly mottled, ^V long. 



A tree, sometimes 20-25 high, with a trunk 6'-8' in diameter, and branchlets at 

 first pale and coated with rusty brown glandular hairs increasing in length during 

 the summer, and slightly puberulous, bright reddish brown, often covered with a 

 glaucous bloom, and marked by a few small scattered pale lenticels during their 

 first winter; more often a low shrub. Bark of the trunk thin, slightly furrowed, 

 light brown, the surface separating into small plate-like scales. 'Wood heavy, ex- 

 ceedingly hard, strong, close-grained, yellow streaked with brown, with light yellow 

 sap wood of 4 or 5 layers of annual growth. 



Distribution. Banks of mountain streams; valley of the Purgatory River, Col- 

 orado, through northern New Mexico to the Santa Catalina and Santa Rita Moun- 

 tains, Arizona, up to elevations of 7000 above the sea-level, and to southern Utah; 

 probably of its largest size near Trinidad, Colorado. 



Occasionally cultivated as an ornamental tree in the eastern states, and in western 

 Europe. 



3. Robinia viscosa. Vent. Clammy Locust. 



Leaves 7'-12' long, with stout nearly terete dark glandular-hispid clammy peti- 

 oles, and 13-21 leaflets; stipules subulate, chartaceous, often deciduous or developing 

 into short slender spines; leaflets ovate, sometimes acuminate, mucronate, rounded 

 or pointed at the apex, and wedge-shaped at the base, when they unfold covered 



