6 



BOTANY. 



When the incisions of a leaf-margin are much deeper 

 than these, reaching half-way to the midrib or petiole, the 

 divisions of the blade so formed are called lobes (Figs. 

 1 6, 17), and the spaces between the lobes are called sinuses, 

 or fissures. 



If the blade be divided nearly to the base or midrib 

 (Fig. 1 8), the partings are termed partitions, and the leaf 

 v* partite; if it is divided quite to the base, or midrib, the 



FIG. 20. 



FIG. 18. 



FIG. 19. 



parts are called segments, and the leaf is said to be dissect- 

 ed (Fig. 19). When the basal lobes, partitions, or seg- 

 ments of a palmate leaf are themselves again divided, so 

 that the whole resembles a bird's foot, the leaf is said to 

 be pedatifid, pedatipartite, or pedatisected, according to the 

 depth of the divisions. Fig. 20 represents a pedatipartite 

 leaf. 



In describing such incised leaves, they are said to be 

 bifid, two-lobed ; trifid, three-lobed, etc. ; or bipartite, tri- 

 partite ; bisected, trisected, etc., according to the number 

 of lobes, partitions, or segments. Another way of describ- 

 ing them depends upon the venation. If the leaf is feather- 

 veined, it is said to be pinnatifid, pinnatipartite, or pin- 

 natisected, etc. When palmate-veined leaves are deeply 



