ACERACEAE 



resistant but it is not suited for use on sites where water is not 

 available while the trees are becoming established, nor for use in 

 our low and extreme desert regions. As it is a fast growing tree 

 it has been used extensively in the past for ornamental and street 

 planting. It, however, harbors a bug which becomes very annoying 

 about dwellings and for this reason such trees as the ashes, elms 

 and walnuts arc much to be preferred even though they require a much 

 longer time to become shade trees. The box elder is probably better 

 for erosion control along mountain streams than the cottonwood, 

 being less likely to be toppled over by flood waters. 



Acer gra nd i de nt a turn may we 11 "be called the Western Sugar 

 Maple* It resembles the' eastern sugar maple and has been used, though 

 not extensively, for the production of maple sugar. It is not un- 

 common in canyons in the mountains throughout the Rocky Mountains. 

 Commonly it is a small, symmetrical and very handsome tree which 

 grows singly or forms dense thickets • It, however, occasionally 

 grows to a height of 40 to GO feet and roaches a diameter of a foot 

 or more. This is worthy of a much wider use both as an ornamental 

 and for erosion control. Its small size and comparative scarcity 

 probably precludes its extensive use as a sugar tree. 



Acer g lab run , Rocky Mountain Maple, is abundant in many parts 

 of the Roc ley Mountains. It becomes relatively scarce in our south- 

 western ranges. It can be classed as a large shrub, never becoming 

 a real tree. Dense clumps of it form excellent soil binders but it 

 can hardly be considered an erosion control plant of significance 

 as it grows at altitudes and under moisture conditions where erosion 

 is not so seriously considered at present. It i s probable, however, 

 that, in the not distant future our erosion control program will ex- 

 tend up into the high summer sheep ranges much more than it is at 

 present. At this time this shrub maple may prove a boon. It should 

 be mentioned that this plant is used successfully as an ornamental 

 in the western plains regions and in the Rocky Mountains. Its 

 loaves turn scarlet in the fall. 



Since the maples generally, produce wood of excellent quality, 

 are usually fairly rapid-growing, beautiful ornamentals and are good 

 soil binders, they should rocemmend themselves for selection work 

 and even extensive hybridization. The work of the Chinese and 

 Japanese with the maples might wo 11 be emulated by nurserymen in 

 this country. 



SAPIMDACEAE 



Do done a visco sa, Hop Bush, is an abundant shrub in southern 

 Arizona. Along the Apache Trail it covers whole hillsides in al- 

 most pure stands. Outside of our boundaries it is practically world- 

 wide in the Tropics. Being quite sensitive to cold it is found only 



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