IOWA ACADEMY OF SCIENCES 
81 
Scarlet Oak {Quercus coccinea Muench.) occurs in the Missouri for- 
ests, and has entered the southeastern counties of Nebraska (59) from 
Richardson to Cass. 
Black Oak (Quercus velutina Lam.) is found in the Missouri forests, 
from which it has moved northward along the eastern border of Nebraska 
(60) to the Platte river. 
Black Jack Oak (Quercus marilandica Muench.) of the Missouri' for- 
ests, has moved into the southeastern counties of Nebraska (61), Richard- 
son to Pawnee and Nemaha. 
Laurel Oak {Quercus imhricaria Michx.) is found in the Missouri for- 
ests, from which it has moved northwestward nearly or quite to the south- 
eastern corner of Nebraska (62). Although this species has repeatedly 
been reported from this part of the state, I have seen no specimens which 
were collected within our borders. I have specimens collected in Mis- 
souri but a short distance from the southeastern extremity of Nebraska. 
Family Betulaceae. 
Ironwood (Ostrya virginica (Miller) Willd.). The small nut is en- 
closed in a bladdery bag, which is so much larger that it serves the pur- 
pose of a wing. A dozen or more of these are aggregated into a loose 
strobilus. The obvious purpose of this structure is the easy transporta- 
tion of the seed by the wind either ^n the whole strobilus, or the separate 
seed-bearing bags. The tree is abundant in the Missouri forests, from 
which it has extended up through the .eastern and northern counties to 
Brown, Cherry and Sioux counties (63). 
Walter Beech {Carpinus caroUniana Walter.). The small nut is 
attached to a foliaceous, somewhat three-lobed bract, which serves as a 
wing. These bracts are not crowded into a strobilus, but constitute a 
loose raceme. On falling from the tree the bracts serve to float the seed 
in the wind for some distance from the parent tree. This species occurs 
in the Missouri forests and has been reported from eastern (Sarpy 
county) and northern stations (Brown county) in Nebraska (64) to 
which it has apparently extended its range. 
Canoe Birch {Betula papyrifera Marshall). This tree occurs in Min- 
nesota and Montana, the Black Hills of North Dakota, and at a single 
station on the Iowa river in central Iowa (Hardin county). In Nebraska 
it is found only on the bluffs and in the ravines along the Niobrara River 
in Keya Paha, Brown, and Cherry counties (65). The occurrence of this 
tree in Nebraska is a puzzle to the botanical geographers for it is diffi- 
cult to conceive of any means by which the seeds could be carried from 
the nearest known stations. Even should we consider the possibility of: 
its dissemination from the Black Hills the difficulty is nearly as great,, 
for the distance is fully one hundred and fifty miles, a part of it across; 
the very rough country known as the “Bad Lands”. 
River Birch {Betula nigra L.) is found in the Missouri forests south- 
eastward, and has extended its range northward along the eastern border 
of the state, being reported from Cass county (67). 
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