34 AMERICAN MIDLAND NATURALIST 
to those of P. tremula. I have collected specimens of P. gran- 
didentata in which the petioles were nearly as long as the leaf- 
blades, so Willdenow’s name “Langstielige Pappel’’ is fully as 
applicable to P. grandidentata as to P. tremuloides. In both 
species the petioles are more or less compressed. Darlington 
(Fl. Cestr. 568, 1837.) and. Torrey (Fl. N.Y. 2: 214, 1843.) eld 
P. trepida identical with P. grandidentata. 
The synonymy of P. tremuloides so far as we know is: 
Populus tremuloides [I,. C. Rich.]; Michx.’ Fl. Bor. Am. 27) 243) 
1803. Duham. Traite des Arb. 2: 184, 1804 (excel. t. 53). 
Michx: fjsHist. Arb. 3:)..285, ¢..8;-f. 13 1813.) Muhly Capeaoee 
re1z. Darley). ve. Tort: 1. .e Sarg. Silva 9: \158) t:7437,eeeee 
(in part). Man. 1905 (in part). 
P. trepida Pursh, Fl. Am. Sept. 2: 618, 1814, not Willd. 
P. tremuliformis Emerson, Trees 243, 1846. 
Medium-sized tree with greenish-gray bark: twigs brown to 
chestnut color: leaves varying from sub-orbicular and acuminate 
to orbicular and abruptly acuminate, serrulate, the callous teeth 
incurved, ciliate, normally 3.5—4 cm. in length; petioles compressed, 
equaling or exceeding in length the blade: staminate aments 
(f. r.) about 5 cm. in length the caducous bracts rather regularly 
laciniate; stamens about 8, anthers small .5 mm., (more or less) 
long: pistillate aments (f. 2.) about 5 cm. long or more; the cupula 
rather coriaceous, 3 mm. more or less in length, tapering gradually 
towards the base. 
