264 Botany of Ulinois and Missourr. 
a mark of doubt. Iam now convinced that they do not be- 
long to that species. 
Cornus florida Lin. 
Hav. On the banks of the Illinois river, 50 miles above 
its mouth—-not common. March—April. 
Cornus circinata Willd. 
Has. On the American bottom opposite to St. Louis. 
April. 
Cornus sericea Willd. 
Han. With the last. 
Plantago virginica L2%. 
Has. Near St. Louis and elsewhere—common. 
It varies considerably in height and in the size of its leaves. 
Plantago pusilla Nw tt. 
Has. On the mounds about one mile north of St. Louis. 
April. The specimens which I observed were about three 
inches high; and were not armed with the subulate bracts 
belonging to P. aristata of Michaux, with which this species 
has been confounded. 
Ptelea trifoliata Lin. 
Has. Timbered alluvions of the Mississippi, at St. Louis 
and elsewhere. May. In my specimens the leaves are 
generally pubescent on the under surface, and have a whitish 
~ eolour. 
TETRANDRIA. TETRAGYNIA. 
Potamogeton gramineum Mich. 
Potamogeton lucens Lin. 
Both these species are found in ponds west of St. Louis. 
July. 
(To be continued.) 
