ADDITIONAL OBSERVATIONS. 
*23 
From Dr. G. Engelmann, of St. Louis, I learn that the 
White Oak, (Q. alba,) and the Rock Chestnut Oak, (Q. 
montana, W illd.,) grow in that vicinity, where there are 
two varieties of each with sessile and with pedunculated 
fruit, in this respect agreeing with the two varieties of 
the English Oak, (Q. robar ,) which have been considered 
as two species. He also informs me that the Chinque- 
pin Oak, ( Q. prinoides, W illd.; Q. primes chincapin, Mich. 
Sylva, t. 11,) grows commonly in South-western Mis- 
souri. He also adds, that the Spanish Oak, ( Q.falcata ,) 
he has only seen in the southern extremity of Missouri; 
and that the W ater Oak, ( Q. aquatica ,) grows no nearer 
to him than the banks of the Arkansa. 
In regard to the western range of our forest trees, 
Doctor Engelmann informs me, by letter, that though 
the Chestnut ( Castanea americana ) does not grow in the 
immediate valley of the Mississippi, it still reappears 
again in south-western Missouri and the north-western 
portion of Arkansas, w r here is also found the Locust 
tree, ( Robinia pseudacacia.') 
The Sweet Gum tree, (JLiquidambar styracijlua ,) he saw 
on the borders of the Wabash; it grows also in Southern 
Missouri and all through Arkansas to the province of 
Texas, but he has not seen it through the greater part 
of Missouri and Illinois. 
The Black Gum tree, (iVyssa multiflora, W alt. N. Syl- 
vatica, Mich. Sylva, t. 110,) according to Dr. En gelma nn , 
is common in the southern parts of Missouri. 
The Wahoo Elm, ( Ulmus alata,) Dr. Engelmann finds 
as far north in Missouri as the vicinity of Herculaneum. 
Around Cape Girardeau, one hundred and fifty miles 
south of St. Louis, he also observes the Tulip tree, 
i (Liriodendron . ) 
Beech trees, the Doctor informs me, he has not seen 
