SAPINDACE. 
10 SILVA OF NORTH AMERICA. 
the leaves turn a dull yellow-brown color and fall rather earlier than those of the Sugar Maple. The 
flowers are produced in many-flowered nearly sessile umbel-like corymbs, the sterile and fertile flowers 
in separate or in the same clusters on the same or on different trees ; they appear with the leaves and are 
greenish yellow, and droop on slender thread-like hairy pedicels from two and a half to three inches in 
length. The calyx is broadly campanulate, five-lobed by the partial union of the sepals and pilose on 
the outer surface toward the base. There are seven or eight stamens with slender glabrous filaments 
which in the sterile flower are nearly twice as long as the calyx, and in the fertile flower are shorter 
than the calyx. The ovary, which is minute in the sterile flower, is obtusely lobed, pale green, and 
covered with long scattered hairs. The fruit is glabrous, with wings varying from one half of an inch 
to an inch in length, and convergent or wide-spreading. 
Acer nigrum is distributed from the valley of the St. Lawrence River in the neighborhood of 
Montreal ' southward to the valley of Cold River, New Hampshire,’ and through western Vermont,’ and 
westward through northern New York, Ontario,’ the southern peninsula of Michigan, Indiana, Ilinois, 
and Iowa, to northeastern South Dakota,® western Missouri,® and eastern Kansas,’ and southward through 
western New York and Pennsylvania to southwestern Virginia® and Kentucky. Comparatively rare 
near Montreal and in Vermont, the Black Maple becomes more abundant farther west, and, growing with 
the Sugar Maple, it can be distinguished at a glance from that tree in summer by its heavy drooping 
leaves, which make it a conspicuous object in the forest or by the roadside, and at all seasons of the 
year by the color of its young branches. In Iowa it almost entirely replaces Acer Saccharum, and 
it is the only Sugar Maple of South Dakota. 
The Black Maple was first distinguished by the younger Michaux. It is often cultivated as a shade 
tree, particularly in those parts of the country where it grows spontaneously. 
always present, but they often occur on such branches, and they 5 In South Dakota Acer nigrum grows in Roberts County, where 
can always be found on vigorous shoots so far as I have been able 
to examine them on both cultivated and wild trees. 
1 Acer nigrum was collected by Mr. J. G. Jack in August, 1895, 
at Rockfield, Quebec. 
2 Acer nigrum was collected by Mr. M. L. Fernald in the allu- 
vium of Cold River, in Cheshire County, New Hampshire. (See 
Rhodora, iii. 234.) 
8 Acer nigrum was collected by Mr. Ezra Brainerd in Middle- 
bury, Vermont, in 1879, and by Miss M. A. Day at Manchester, 
Vermont, on June 25, 1898. The younger Michaux speaks of 
having noticed the Black Maple at Windsor, Vermont, on the Con- 
necticut River, but I have seen no specimens from the eastern part 
of the state. 
* See Macoun, Cat. Can. Pl. i. 99. 
it is abundant in deep ravines along the small streams which form 
the Little Minnesota. (See D. H. Saunders, Bull. 64, South Dakota 
Agric. College, 169 [Ferns and Flowering Plants of South Dakota}.) 
In the second volume of this work the range of the Sugar Maple was 
probably incorrectly extended to eastern Nebraska. Later obser- 
vation indicates that the Sugar Maples of that state have been 
planted since the settlement of the region by white men, and that 
this tree, although reaching South Dakota and Kansas, is not a 
native of Nebraska. (See Bessey, Rep. Nebraska State Board 
Agric. 1899, 89 [The Forests and Forest Trees of Nebraska.) 
° Near Independence, Missouri, 1894, B. F. Bush (No. 130). 
7 Lawrence, Kansas, J. H. Carruth, 1894. 
® Falls of the Holston, Smythe County, Virginia, John K. Small, 
July, 1892. Alleghany Springs, C. Mohr, August 10, 1898. 
EXPLANATION OF THE PLATE. 
Puate DCXXV. AceER nigRUM. 
oe i 
“ID Cr 
. A flowering branch, natural size. 
A staminate flower, enlarged. 
A pistillate flower, enlarged. 
A fruiting branch, natural size. 
A fruit, natural size. 
A fruit, natural size. 
. A winter branchlet, natural size. 
