EOEBST TREES. 93 



in diameter, but only on ~vexy favorable eituations does it 

 grow to sucb a size. Wood very hard, resembling that of the 

 Sugar Maple, and one of the best and most valuable hard woods 

 found west of the Rocky Moimtains. The sap is sweet, and 

 yields a fair quality of sugar. This maple occurs in California, 

 from Santa Barbara, and northward, to Washington Territory. 

 It is a tree well worthy of the attention of arboriculturists, 

 East as well as in the West ; but the seed should be procured 

 from Northern localities, and from large trees, else the plants 

 are likely to be tender and of slow growth in localities east of 

 the mountains. 



A. gmndidcatatnin. — Mountain Sugar Maple. — Leaves slightly 

 cordate or truncate at the base, pubescent beneath, and rather 

 deeply three-lobed; lobes acute with a few sinuous indentations. 

 Flowers few ; the petals nodding. Seed smooth, with small, 

 diverging wings. This species, although closely related to the 

 Sugar Maple, does not attain a very large size, seldom growing 

 more than thirty feet high. It is found in Arizona, Southern 

 Utah, and on the west side of the Mountains, near the head- 

 waters of the Columbia, principally in the valleys, and near 

 small streams. 



A. glabrnnii — Smooth-leaved Mountain Maple. — Leaves smooth, 

 two to four inches broad, rounded, heart-shaped in outline, 

 with rather shallow indentations, although occasionally dis- 

 tinctly three-lobed ; the lobes doubly serrated, with acute teeth. 

 Flower in large coiymbs, oh short branchlets ; greenish-yellow. 

 Seeds, with broad-spreading wings, ripen late in fall. Quite a 

 variable species, both in leaves, color of the branches, and form 

 of growth. This species probably grows at a higher elevation 

 in the Rocky Mountains than any other native maple. I have 

 found it abundant in Colorado and New Mexico, at an elevation 

 of ten thousand feet. In exposed situations, on the sides of a 

 canyon, it was merely a taU shrub, with many stems springing 

 from the same root, probably because frequently kUled down 

 in winter ; but where protected by other trees, it assumes an 

 upright form, growing thirty or more feet high. Wood quite 

 hard, and flne-grained, but, as generally found, it is too small 

 for any practical use except for firewood. Common in the 

 mountains of Northern New Mexico, Colorado, and west to the 

 Sierra Nevada, and northward to Vancouver's Island. 



A. JVegimdo, or Jfegnndo aceroldes.— Negundo Maple, Box Elder, 

 Ash-leaved Maple.— Although our modern botanists consider 



