146 



OEGANOGEAPHY. 



the Dead-nettle {fig. 288), and Lilac. The latter modification of 

 arrangement is sometimes termed true netted venation. 



Fig. 286. 



Fig, 287. 



Fig. 288. 



Fig. 286. Feather-veined leaf of tlie Spanish Chestnut. 



Fig. 287. Feather-veined leaf of the Oak. Its 



lobes are arranged in a piiiuatifld manner. Fig. 



288. Leaf of the Dead-nettle. The venation is the 

 true netted, and its margin is sen-ated. 



2. Badiated- or Palmately-veincd. — Tliis name is applied to a 

 leaf which possesses three or more ribs that arise from at or near 

 the base of the lamina, and diverge from each other towards its 

 margin, and are connected by branching veins, as in the Melon 

 {fig. 284) and Castor Oil {fig. 306). The ribbed venation, as seen 

 in the Cinnamon {fig. 283), is but a modification of this variety, 

 in which the ribs instead of diverging from each other, run in a 

 curved manner from at or near the base of the blade to the apex, 

 towards which they converge ; such 

 ribs being connected together by branch- 

 ing veins. If a ribbed leaf has three 

 ribs proceeding from the base, it is said 

 to be three-ribbed or tricostate ; if five, 

 fiive-ribbed or quinque-costate ; if more 

 than five, midticostate. If the midrib 

 of such a leaf gives off on each side, a 

 little above its base, another rib, it is 

 said to be triple-ribbed or tripli-costate, 

 as in the common Sunflower {fig. 289, 

 b) ; or if two such ribs arise on each 

 side of the midrib, it is termed quin- 

 Fig. 289. I. Tripie-ribhed tuple-ribbed or quintupU- CO state. These 

 leaf of the common ribbed leaves have frequently a great 

 sunflower, a. Linear ^eg^j^blauce to parallel-veined leaves, 



F\g. 289. 



