IOWA ACADEMY OF SCIENCES 
79 
Family Riiamnaceae. 
Buckthorn {Rhamnus lanceolata Pursh) is common in the Missouri 
forests, from which it has moved up along the eastern border of the state 
to Cherry county on the Niobrara river. It has followed the tributaries 
of the Missouri river (Nemaha and Blue rivers) to Gage, and (Platte 
river) Saunders counties (38). 
Indian Cherry {Rhamnus caroliniana Walt.) occurs somewhat spar- 
ingly in the Missouri forests, from which it has advanced into eastern 
Nebraska (39) having been noticed at two stations (Cass and Saunders 
counties). 
Family Elaeagnaceae. 
Buffalo Berry {Lepargyraea argentea (Pursh) Greene) The small red 
or amber one-seeded drupes are edible, and are eaten by birds and thus 
carried away. The seed is protected from injury in the alimentary canal 
by its hard covering. This small tree is a native of the Rocky Mountain 
region and westward, from which it has been carried eastward across the 
state (40) to the banks of the Missouri river (Nemaha county). 
Family PIippocastanaceae. 
Buckeye {Aesculus glalyra Willd.). The large brown shiny seeds drop 
to the ground as soon as mature, where they are quite conspicuous. Here 
they are picked up by large animals and sometimes swallowed. They are 
too hard to be easily masticated, and many must be rejected after trial. 
In the meantime they have usually been carried some distance from the 
parent tree. This species occurs in the Missouri forests, from which it 
has moved into Nebraska (41) as far as Richardson, Pawnee and Nemaha 
counties. 
Family Aceraceae. 
Silver Maple (Acer saccharinum L.) occurs abundantly in the Missouri 
forest area from which it has extended up the Missouri River nearly to 
the mouth of the Niobrara river (43) and w’estward fifty to sixty miles, 
in the moist lands along the streams. 
Box Elder or Ash-leaved Maple (Acer negundo L.) grows abundantly 
in the Missouri forests, from which it has extended across the state (44). 
As this species occurs in the Rocky Mountains from New Mexico north- 
ward it is possible that seme of the trees in western Nebraska have come 
down from the mountains and met those disseminated directly from the 
eastern forest areas. 
Family Anacardiaceae. 
Sumach {Rhus copallina L.). The small one-seeded drupes are crim- 
son in color and have an acid flavor. They are eaten by birds, and their 
seeds are protected from injury by the bony seed coat. This species oc- 
curs in the Missouri forests, and has been carried northward (45) to th« 
CKtreoae southeastern corner of the state (Richardson county). 
