226 DESCRIPTION OF SPECIES. 



Populus gland II lifera, Heer. 

 Plate XLVIa, Figs. 3, 4. 

 Heer, " Fl. Tert. Helv.," p. 17, pi. Iviii, figs. 5-11 ; " Fl. AlaBk./' p. 26, pi. ii, figs. 1, 2. 



Leaves glandulose at the point of attachment of the petiole, variable in size, 

 elliptical-ovate, pointed or generally enlarged on the sides and broadly deltoid, serrate 

 or callous-dentate all around, five to seven palmately nerved ; nerves branching outside. 



The two specimens figured here do not show any impression of glands 

 at the top of the petiole ; but in both the collections of Professors McBride 

 and Winchell there are finely preserved leaves of the species with dis- 

 tinctly marked glands. All the leaves are comparatively small ; the one, 

 pi. 4, is the largest of those I have seen. 



Hab. — Bad Lands, Dakota. Denton's, McBride's, and WinchelVs col- 

 lections. 



Populus latior truncata, Al. Br. 



Plate XLVI, Fig. 14. 



Heer, " Fl. Tert. Helv.," p. 14, pi. Ivii, fig. 2. 



Leaf subtruncate at base, large; primary nerves five, the lower marginal, thin, 

 the upper strong, branching outside; borders distantly serrate. 



The leaf is perhaps too fragmentary for satisfactory identification. 

 Comparing it, however, with Heer's figure, loc. cif., it does not appear to 

 differ except by the base of the leaf being slightly more rounded. 



Hab. — Bad Lands. Professor Wm. Denton. 



Populus balsamoides, var. eximia, G-oepp. 

 Plate XLVI A, Fig. 10. 

 Populus eximia, Goepp., "Schoss. ¥].," p. 23, pi. xvi, fig. .'>; xvii, fig. 3. 



Leaves large, cordate at base, ovate-lanceolate, obtuse or acute, deeply crenate; 

 lateral nerves at an acute angle of divergence, camptodrome, reticulate along the 

 borders. 



This fragment, though the base and apex of the leaf are destroyed, 

 appears referable to this species. The substance of the leaf is mem- 

 branaceous, the surface very smooth, the lateral nerves less curved and 

 stronger than in any of the figures of Goeppert. The species is also 

 finely represented in Gaudin's "Contrib.," i, p. 29, pi. iii, figs. 1-5; but 

 here, also, the secondary nerves are thinner and more curved. The true 



