HARPER: BOTANICAL CROSS-SECTION OF Mississipp1 385 
TREES SHRUBS 
Salix n Sambucus canadensis 
Liauidambar Slater Robinia Pseudacacia 
Cornus runus angustifolia 
Pinus e china ta Sassafras variifolium 
Platanus occidentalis Rhus glabra 
Quercus alba 
Puieaa f a ERBS 
Cercis canadensis Asclepias tuber 
Liriodendron Tulipifera Tripsacum dactytoiies 
Populus del Cicuta C 
Quercus marylandica Sorghum Halepense 
Quercus stellata (and several less frequent weeds) 
A noteworthy difference between this list and the one next 
preceding is the presence of Pinus echinata* and Liriodendron, 
species which do not grow in the richest soils. I am not sure that 
any of the shrubs and herbs listed could have been found in pre- 
historic times in the places where I saw them. 
Post-oak flatwoods. The oldest Eocene formation in Missis- 
sippi underlies the “‘ post-oak flatwoods,” which lie immediately 
west of the Pontotoc Ridge in Union County and of the prairie 
region in Clay County, and extend southeastward into Alabama. 
This belt is nowhere more than 15 miles wide, and where I crossed 
it on the westward trip its boundaries seemed so ill-defined, that 
I could not very well separate my notes on it from those on ad- 
jacent regions. On the way back, however, I had little trouble 
in locating its western edge near Hickory Flat, and its eastern 
edge at the western base of the Pontotoc Ridge, near New Albany. 
The Lafayette formation seems to be absent in the flatwoods, 
and the Eocene strata have weathered into a very stiff clay, con- 
taining, according to Dr. Hilgard’s analyses, 0.08-0.18% of lime, 
0.25-0.75% of potash, 0-0.05% of phosphoric acid, and 0.17- 
0.85% of magnesia. Both its physical and its chemical properties 
make this soil ill adapted to agriculture, and the region is very 
thinly settled. This part of Mississippi has been described by 
Hilgard,j Hurt,t and E. J. Hill,§ and in the government soil 
surveys of Pontotoc, Clay and Oktibbeha Counties. 
20129 Pie, Sareenld wag of the pine forests of Mississippi (opposite page 53° of the 
oth volume of the Tenth Census) does not indicate the occurrence of any pine at all 
in this region 
t Geol. & Agric. Miss. 273-288; Tenth Census 5: 224-227, 294-296. 
$ Op. cit., 12-14. 
§ Torreya 6: 231-232. 1906. In this interesting paper, based on observations 
made in Oktibbeha County in 1858, the post-oak flatwoods west of Starkville are 
