DESCIIIPTION OF SrECIES-imAMNE/E. 273 



PALIURUS, Tourn. 

 P a I ■ II ■' m s C (> I <> III b i , Heer. 



riiito L, Figs. 13-17. 



ruUunis Culombi, Uccr, Arct. Fl., i, ]i. 1-"J, pi. xvii, lis. '-><(; six, figs. 2-4 ; ii, p. 482, pi. 1, figs. 18, 19; 

 Sl)itzb. Mioc. Fl., p. 07, pi. xiv, lig. 11.— Lescix., Auuual Report, 1871, p. 288; 1872, p. 'iS>i. 



Loaves oval, equally narrowed upward to au obtuse point and downward to a very short petiole ; 

 borders mostly entire, Bometimes with one or two obtuse teelh ; lateral nerves in an acute angle of 

 divergence, curving inside, and anastomosing v\ith secondary nerves or their branches toward the point; 

 nervation cauiptodroine. 



These leaves arc slightly smaller than those figured by Heer; but, other- 

 wise, they agree in all their characters; even, among the numerous specimens 

 from Carbon, some fragments represent leaves quite as large as those from 

 Greenland. All the large leaves have the borders entire; the small ones are 

 sometimes marked by one or two obscure or obtuse teeth, a character indi- 

 cated also in fig. 2 </ of pi. xvii of the Arctic Flora; all are sessile, or nearly so, 

 bearing only sometimes traces of a very short petiole (fig. 14 of our j)late). 

 They are triple-nerved from the base, the lateral nerves branching outside, 

 ascending to above the middle, where they unite by branclilets to the sec- 

 ondary ones. These, generally few, three or four pairs, in the upper part of 

 the leaves curve in passing to the borders, which they closely follow parallel 

 to the branches, and anastomosing with them in simple festoons. One of tiie 

 specimens to the leaf represented in tlie Arctic Flora (pi. xxvii, fig. 2d) has, 

 not in connection, ])ut in the direction of its base, a fragment of a slender, 

 apparently long, petiole. If the reference of this fragment to rallurus is riglit, 

 the petiole is there casually out of place, or the leaf may represent the species 

 described before as Fopulus dccipiens (p. 179, pi. xxiii, figs. 7-11), whose 

 leaves an; so very similar by their shape and nervation that I considered 

 them at first, and from the specimen (fig. 7) deprived of a petiole, as repre- 

 senting the same species of Paliurus. This confusion is tlie more easily 

 made, since tlie specimens of both are found together, especially at (Jarbon, 

 where they are abundant. The difierence is merely in the larger size and the 

 .'^hape of the leaves of P. decipievx, which, generally wider in the middle, bear 

 a thin marginal veinlet from under the primary nerves, a character seen upon 

 lig. 3, pi. xix, of the Arctic Flora. The first description of this Paliurus (in 

 Annual Report, 1871, p. 288) was made from leaves of these two different 

 species. By the shape of the leaves and the nervation, this species is allied to 

 Ceanothus thyrsijloru^, Esch., of California. 

 18 r ¥ 



