LECT. X.] COMPOUND LEAVES. 527 



joint at the point of attachment, as in prickly- 

 leaved Fagara, Fagara tragodes *, 1 00. 



f02 



In the majority of plants the form of the 

 leaf, whatever that may be, is the same over 

 the whole of the plant; but there are exceptions 

 to this rule ; and when the diversity in the form 

 of the leaves is constant, the term heterophyl- 

 lus is occasionally adopted as the specific naine 

 of the plant. Thus various-leaved Spurge, Eu- 

 phorbia heterophylla, is named from having the 

 lower leaves short, wedge-shaped, emarginate 

 and mucronate, while the upper are long linear- 

 lanceolate, acute, and entire, 101. Heterophyllous 

 plants, however, must not be confounded with 



* Mirbel (Elem. de Phys. veg. Zde Partie, p. 655) quotes 

 the leaf of spike-flowered Cussonia, a curious Cape plant, as an 

 example of the vertebrated leaf; but this Cussonia presents an 

 instance only of a digitated leaf, with articulated, winged, se- 

 condary petioles. 



