NOTES ON POPULUS, PLINIUS 33 
It was definitely separated from the European tree by Richard: 
“Populus tremuloides: P. foliis parvulis, suborbiculatis, abrupte 
acuteque acuminatis, serrulatis, margine pubescentibus. Hab. in 
Canada et Noveboraco.” [L. C. Rich.] Michx. Fl. Bor. Am. 2: 
244, 1803. 
In 1804, Duhamel (Traite des Arb. 2: 184, t. 53.) published the 
following note in addition to the brief description of P. tremulaides 
“Ce Peuplier, dont on doit la decouverte a Michaux que l’a porté 
de l’Amerique septentrionale en Europe, ne differe notre Trem- 
ble que par les dentelures de ses feuilles. Le Tremble les a grandes 
et dans une direction droite; dans les faux Tremble elles sont fines 
et dirigées obliquement vers le sommet de la feuille. Ce Peuplier 
est maintenant en France dans quelques jardins.” 
The description given by Duhamel applies to P. tremuloides 
but the illustration (t. 53) represents P. tremula and not at all 
our American Aspen. 
Pursh [Fl. Sept. Am. 2: 618, 1814.] refers the tree to Populus 
trepida of Willdenow [Sp. Pl. 4: pt. 2. 803, 1806?]. He cites the 
iiseravions eiven by), Michaux|'f. ‘(Hist Arb. 3: 285) 0.18) 1504, 
1813) and also that of Duhamel (1. c.). There are doubts as to 
the identity of P. trepida with P. tremuloides. The description 
given by Willdenow (1. c.) points to P. grandidentata rather than 
to P. tremulordes. 
“Populus trepida. 
P. foliis suborbiculatis dentatis bast supra biglandulosis acuminatis 
glabris, guntoribus sericeis. W. 
Populus trepida Muhlenberg in litt. 
Langstielige Pappel. W. 
Habitat in America borealis. [Arbor] (v.s.s.fl.) 
Valde similis sequenti [P. tremula], sed folia acuminata, et 
petiolis non compressi licet longissimt. Folia juniora utrinque 
sericea alba, adulta vero glaberrima basi supra biglandulosa.” (Willd. 
Ieee) 
Muhlenberg, who evidently sent specimens to Willdenow, 
referred P. grandidentata to P. trepida (See Muhl. Cat. 92, 1813.) 
Moreover, the description of the leaves given by Willdenow would 
lead one to assume that he had P. grandidentata and not P. trem- 
uloides. ‘The young leaves of the former are strikingly sericeous 
and almost as conspicuous as those of P. canescens. In age the 
leaves are glabrous and some forms have somewhat of a resemblance 
