206 THE FLORA OP THE DAKOTA GROUP. 



diversity of characters seen in the leaves of Liriodendron (k^scrihed in this 

 vohime, 1 beUeve that no botanist would be disposed to consider them as 

 mere varieties of the original, obovate, simple leaves. 

 Habitat : Nebraska. Specimens not seen. 



Liriodendron giganteum Lesq. 

 PI. XXV, Fig. 1 ; ri. XXVI, Fig. 5 ; PI. XXVII, Fig. 1. 



Cret. Fl., p. 93, PI. xxii. Fig. 2; Uret. and Tert. Fl., p. 74. 



Leaves large, broadly bilobate on each side, deeply emarginate at 

 apex; lobes at right angles or oblique, oblong, obtuse; sinuses deep, com- 

 paratively narrow ; lateral nerves simple, oblique, parallel, straight, and stout. 



There are many leaves of this species, all large, the largest (PI. XXVI, 

 Fig. 3) measuring 16.5"™ in width between the extremities of the lower 

 lobes, 10"" in length from the top of the petiole (broken) to the apex of the 

 median nerve, or IG""" to the top of the upper lobes. The secondaries, 

 which of course follow the angle of divergence of the lobes, are at an angle 

 of 50° to 80° to the median nerve. The leaf (PI. XXV, Fig. 1) has the 

 lobes more oblique, narrower, while that shown in PI. XXVII, Fig. 1, has 

 the lobes more open and more deeply divided. But all are evidently of 

 the same species and of the same character as the one described in Cret. 

 Fl., p. 93, PI. XXII, Fig. 2, which is only a fragment of the upper part of 

 an apicial lobe. 



Habitat: Two miles from Glascoe, Kansas. Nos. 20(5, 335, and 513 of 

 the Museum of Comparative Zoology of Cambridge, Massachusetts. 



Liriodendron giganteum var. cruciforme Lesq. 

 PL XXVIII, Figs. 1, 2. 



Liriodendron cruciforme Lesq., Cret and Tert. Fl., p. 74 ; Bull. Mus. Comp. Zool., 

 Cambridge, vol. 7, pt. 6, 1881, p. 227. 



This variety as seen from better preserved specimens merely differs 

 from the normal form by the lobes l)eing nearly at right angles, more deeply 

 cut to the narrow sinuses, less oblique and merely obtusely pointed; the 

 nervation is of the same type. 



Habitat: Elkhorn Creek, Kansas. Nos. 192 and 197 of the Museum 

 of Comparative Zoology of Cambridge, Massachusetts. 



