96 
SILVA OF NORTH AMERICA. 
SAPINDACE. 
of five or six thousand feet, although at the north it sometimes descends to within a few hundred feet 
of the sea-level. 
It is rarely more than a low shrub, and only in some of the elevated canons of New 
Mexico, Arizona, and Idaho assumes the habit of a tree. 
The wood of Acer glabrum is heavy, hard, and close-grained ; it is light brown or often nearly 
white, with thick lighter colored sapwood and numerous medullary rays. 
The specific gravity of the 
absolutely dry wood is 0.6028, a cubic foot weighing 37.57 pounds. 
Acer glabrum was discovered in the valley of the Bear River by Dr. James,’ the naturalist of the 
United States Exploring Expedition which reached the Rocky Mountains in 1820 under command of 
Major Stephen H. Long. 
It was introduced several years ago into the Botanic Garden of Harvard 
College, where, as in the Arnold Arboretum, it is perfectly hardy, forming a small shrub which flowers 
and fruits every year. 
* Edwin James (1797-1861), best known as the botanist and his- 
torian of Long’s Rocky Mountain Expedition, was born in Wey- 
bridge, Vermont, and educated at the Middlebury Academy in that 
state, afterwards studying medicine in Albany, New York, where, 
under the inspiration of Eaton, he became interested in natural sci- 
ence. In 1820 Dr. James, having been appointed a surgeon in the 
United States army, was attached as naturalist to the party sent to 
explore the then little known central part of the continent, and 
made many interesting discoveries on the alpine heights of the cen- 
tral Rocky Mountains, which he was the first botanist to reach. Dr. 
James remained in the army until 1830, and then returned to 
Albany where he engaged in editorial duties, and in 1836 removed 
to Burlington, Iowa, then on the very edge of the wilderness. 
Extreme views on moral and religious subjects separated him from 
the world, and he passed the last years of his life, brought to an 
end by an unfortunate accident, as a recluse. Jamesia, a delicate 
shrub of the Saxifrage family, represented by the single species 
discovered by Dr. James in the Rocky Mountains, perpetuates his 
name. (See Am. Jour. Sci. ser. 2, xxxiii. 428.) 
EXPLANATION OF THE PLATE. 
PiateE LXXXIX. AcER GLABRUM. 
1. A branch with staminate flowers, natural size. 
2. A branch with pistillate flowers, natural size. 
3. Vertical section of a staminate flower, enlarged. 
4. Vertical section of a pistillate flower, enlarged. 
5, 6. Fruiting branches, natural size. 
7. Vertical section of a fruit, enlarged. 
8. Vertical section of a seed, enlarged. 
9. An embryo, much magnified. 
10. A three-parted leaf, natural size. 
11. A winter branchlet, natural size. 
