220 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



Dudley willow. Very similar to the black willow of the eastern 

 United States (S. nigra). Along the lower courses of the Colorado 

 and Gila Rivers it forms veritable forests, growing with cottonwood 

 (Populus fremontii), attaining a height of 13.5 m. (45 feet) and a 

 trunk diameter of 75 cm. (30 inches) or more. The typical pubescent 

 form is less common than the glabrous or glabrate form. 



10. Salix amygdaloides Anderss., Amer. Acad. Arts and Sci. Proc. 4: 



53. 1858. 



Tunitcha Mountains (Apache County), Rincon Mountains (Pima 

 County), up to 7,000 feet, along streams, apparently rare in Arizona. 

 Quebec to British Columbia, south to New York, Texas, Arizona, and 

 Oregon. 



Peachleaf willow. Usually treelike but seldom more than 9 m. 

 (30 feet) high and 30 cm. (12 inches) in trunk diameter. 



11. Salix lasiandra Benth., PL Hartw. 335. 1857. 



White Mountains (Apache, Navajo, and Greenlee Counties), 

 Tonto Basin (Gila County), 5,000 to 6,500 feet, along streams. 

 Colorado to Yukon, south to New Mexico, Arizona, and California. 



Pacific willow. A shrub or small tree, rarely reaching a height of 

 12 m. (40 feet). 



12. Salix bonplandiana H. B. K., Nov. Gen. et Sp. 2: 20. 1817. 

 Yavapai, Greenlee, Gila, Santa Cruz, and Pima Counties, 3,000 to 



5,000 feet. New Mexico and Arizona to Guatemala. 



A handsome tree, usually not more than 7.5 m. (25 feet), but some- 

 times 15 m. (50 feet) high. The more common form in Arizona is 

 var. toumeyi (Britton) C. Schneid. (S. toumeyi Britton), the Tourney 

 willow, with narrower, less deeply dentate leaves and shorter catkins. 



13. Salix lutea Nutt,, North Amer. Sylva 1: 63. 1842. 



Apache County to Coconino and Yavapai Counties, 3,800 to 6,000 

 feet (and probably higher). Nebraska to Alberta, south to New 

 Mexico, Arizona, and California. 



Yellow willow. Usually shrubby. The var. ligulifolia Ball (S. 

 ligulifolia Ball), with narrower leaves than in typical S. lutea and 

 brown rather than yellow bark of the twigs, is much the more common 

 form in Arizona. The twigs in this form are often very pubescent. 



14. Salix pseudomonticola Ball, Contrib. U. S. Natl. Herbarium 22: 



321. 1921. 



White Mountains, Apache County (Coville 2009). Saskatchewan 

 and Alberta to Colorado and Arizona. 



A shrub, not more than 3 m. (10 feet) high. The specimen above 

 cited, not seen by the writers, has been referred to var. padophylla 

 (Rydb.) Ball. 30 The leaves resemble those of S. cordata Muhl. of eastern 

 North America. 



23. JUGLANDACEAE. Walnut family 



1. JUGLANS." Walnut 



A tree, or occasionally shrubby, with strong-scented, pinnately 

 compound leaves; leaflets commonly 9 to 13, large, lanceolate or 



30 Ball, C. It. new varieties and combinations in salix. Wash. Acad. Sci. Jour. 28: 443-452. 1938. 

 (p. 450). 



31 Reference: Sudworth, Georoe B. poplars, principal tree willows, and walnuts of the rocky 



mountain region. U. S. Dept. Agr. Tech. Bui. 420. 1934. 



