Zanthoxylon. TEKEBIXTHIXE.R 33 



borders, where they abruptly curve, joined to the teeth by branchlets, 

 or sometimes passing directly to their points. The intermediate areas 

 are divided by short tertiary veins, connected to nervilles at right angles, 

 or traversed by distinct veinlets also in right angle to the nerves. The 

 ultimate areolation is obsolete. 



By the characters of its nervation this leaflet is equally referable to 

 Rhus or to Zanlhoxylon. In the species of this last genus the leaflets are 

 generally narrowed to the base, or to the petiole ; in some species of 

 Rhus they are sessile, and more generally rounded, truncate, or subcor- 

 date to the base. 



Habitat. — Table Mountain, California, Mixed with the numerous small 

 leaves of Qncrcus convcxa. This was the only specimen found. Voy's 

 Collection. 



ZANTHOXYLON, Linn. 



Zanthoxylon diversifolium, sp. nov. 



PL VIII. Figs. 14, 15. 



Leaves pinnate or trifoliate; leaflet', very variable in size, subcoriaceous, entire, oblong- 

 oval, unequilateral, cuneiform at the base; nervation camptodrome. 



At first siiiht it would seem that these two leaves belong to two dif- 

 ferent species, the largest one being at least seven centimeters long, and 

 nearly four wide, while the other is not half as large, though of the same 

 form. The characters of nervation are identical. The lateral nerves on a 

 broad angle of divergence, variable in distance, the upper ones nearly paral- 

 lel, curve in the same degree in traversing the areas toward the borders, 

 which they follow in simple bows prolonged by anastomosis of veinlets. 

 In both leaves the lowest secondary vein on the narrowed side passes up 

 in a very acute angle of divergence, joining the nerves above by anas- 

 tomoses, either with tertiary veins, or by thick veinlets at right-angles 

 lo the midrib. In both the ultimate areolation of equilateral or sub- 

 quadrate small meshes is formed by subdivision of the veinlets at right- 

 angles. It thus appears that we have two leaflets probably separated 

 from the same leaf, pinnately divided, like most of those of this genus. 

 I find no species in the present flora to which these leaves are related, 

 except Z. tiiphyttum, a trifoliate species from Brazil, communicated to me 



