506 Part IV. Chapter 2. 
bottom shows clumps of willows consisting of Salix amygdaloides, S. cordata, 
S. longifolia and S. nigra. Species of Crataegus occur as isolated individuals 
which in some cases are the only representatives of the species, the Mississippi 
acting as a barrier to their general distribution westward, as is the case also 
with Gleditschia aquatica which occurs on the Illinois side, but not in Missouri. 
The wooded bottom is characterized by Carya amara (= Hicoria minima), C. olivae- 
formis (= H. pecan), Quereus bicolor, Q. macrocarpa, Q. palustris, Gleditschia Tag Populus 
ae Cais mississippiensis, C. occidentalis, Betula nigra, Ulmus americana, and such lianes 
as Ampelopsis quinquefolia, Vitis einerea, V. cordifolia, V. riparia. "The area flora of 
the dry bottoms includes Myosurus minimus, Ranunculus abortivus, R. repens, Anemone penn- 
sylvanica, Dentaria laciniata, Draba brachycarpa, D. caroliniana, Sisymbrium canescens, Cerastium 
nutans and Geranium carolinianum (in a The summer adds Cassia chamaecrista, Crotalaria 
sagittalis, Desmodium canescens, D. brac ml D. cuspidatum), D. Dillenii, D. paniculatum, 
Glycyrrhiza lepidota, Lepedenn a; ie se ‚ Ambrosia EEE er er Aster 
patens, Helianthus ann ‚ tuberosus, Solidago a: S. serotina and other 
On the wet ee are found Isopyrum biternatum, Myosurus minimus, Ka culus abor- 
tivus, succeeded in summer by Hypericum mutilum, H. perforatum, Cassia ae Abutilon 
BETON Amorpha Sr Baptisia leucantha, Asclepias incarnata, Ipomoea hederacea, I. lacu- 
nosa, I. pandurata, I, purpurea, Convolvulus sepium, Stachys palustris, Datura stramonium, D. Ta- 
a Phytolacca decandra, een acre, ui hydropiperoides, P. lapathifolium, Euphorbia glypto- 
sperma, E. humistrata and Boehmeria cylindrica. 
Upland Deciduous Forest Formation. The woods which extend back 
from the river bluffs toward the prairies are decidediy different from those of 
the alluvial bottoms. The trees are of lighter growth and the species are 
fewer in number. The predominating trees are several species of Quwercus and 
Carya which vary according to locality. The undergrowth lacks rankness, 
consisting of patches of hazel, Corylus americana, thickets of Prunus ameri- 
cana, Pirus coronaria, beneutk which are Frasera carolinensis, Arisaema tri- 
phyllum, Podapiedium peltatum and other herbs. The vines of these woods 
are Tecoma radicans, Bignonia capreolata (= B. crucigera), several species of 
Smilax, Humulus lupulus, Dioscorea villosa, Rosa setigera. The Oak Openings 
are a striking feature of southern Illinois and they afford a transition to the 
prairie formation to be considered later in this work. The characteristic oaks 
Quercus imbricaria, O. aquatica (= O. nigra), or in damp situations ©. palu- 
stris are of symmetric shape, uniform size and compact foliage. They arise 
from a grassy turf seldom encumbered with brush but not infrequentiy broken 
by dense growths of dwarf sumac and flowering plants. 
The plateau region of Tennessee is covered by a forest of broad-leaf 
trees which grow on the rolling surface with a soil of poor quality, loose and 
sandy. The following trees distributed originally according to their soil and 
moisture preference occur: 
Carya porcina Nutt. (= Hicoria glabra | Quercus obtusiloba Michx. (= Q. stel- 
Salix nigra Marsh. [Mill.). lata Wang.). 
Castanea dentata Marsh. | » Muhlenbergii Engelm. =Q. 
Quercus alba L. acuminata Houba). 
