Short on the Botany of Illinois. 
197 
styracijlua and Nyssa of two or three species,) whilst the 
poorest soils, those especially of the Tushy barrens’ and ‘•oak 
openings,’ are occupied mostly with the different kinds of oak, 
among which the post-oak, ( Quercus obtusilobaf) and black¬ 
jack, (Q. ferrugineaf) are most prominent. I am able, indeed, 
to indicate but two trees which are in any way peculiar to 
the forests of Illinois; and these are the paccan and catalpa. 
Of these the paccan ( Carya olivcpformisf) is found abundantly 
on the southern borders of the State, where about Shawneetown 
and other points on the Ohio river, it constituted a large por¬ 
tion of the original forest; and from these districts great quan¬ 
tities of the nuts have been exported. They are not consid¬ 
ered, however, to be equal, either in size or flavor, to the pac- 
can-nuts of Texas. The other tree—the catalpa, ( Catalpa 
cordifoliaf) I have the authority of General Harrison for say¬ 
ing, is found occasionally, and of large size, in the alluvions 
of the Wabash river, where he considered it to be certainly a 
native; in opposition to the opinion of the Abbe Correa, who 
thought it more probable that the seeds may have been de¬ 
rived from trees planted by the early French settlers of Vin¬ 
cennes and other posts. I have seen this tree in similar al¬ 
luvions among the dense forests of Henderson county, Ken¬ 
tucky. 
•/ 
Whilst walking over the prairies adjoining the town of 
Bloomington, in company with our friend Dr. John F. Henry, 
who resides there, he pointed out to us an extraordinary phe¬ 
nomenon in connexion with vegetation, and one only visible. I 
suppose, in a prairie country. It was a semicircular, or 
rather horse-shoe-shaped line of herbage, distinguishable very 
plainly from the surrounding and' included growths, by its 
darker or deeper green hue. He said that these circles or 
segments of circles, usually of fifteen or twenty feet diame¬ 
ter, were frequently to be seen in summer, and that it was 
irenerally believed they were occasioned by lightning. He 
described the thunder-storms of this region as sublimely ma¬ 
jestic and terrific. We had no opportunity of witnessing 
this display of Heaven's artillery, during our journey; but 
o 
