48 



MORPHOLOGY 



Figr. 48. — Karabi [Nerium odorum) 



the leaves arise singly from each node, as in Mango, 

 so that if a line or thread is carried round the stem, 



touching the insertion of 

 the leaves in succession, 

 it will describe a spiral. 

 This arrangement is also 

 termed alternate or 

 scattered (see figs. 30, 31). 

 When there are only two 

 leaves in a node facing 

 each other, they are desig- 

 nated as OPPOSITE, as in 

 Guava. When there are 

 more than two leaves in a 

 node, they are said to be 

 VERTiciLLATE. Opposite 

 and verticillately arranged leaves are said to be in 

 whorls. When the successive whorls alternate with 



one another, so that 

 the leaves of one 

 whorl stand in the in- 

 tervening spaces be- 

 tween the leaves of 

 the whorl next above 

 it and next below it, ' 

 they are said to be 

 DECUSSATE, as in 

 karabi and akanda 

 (figs. 48, 49). Phyl- 

 LOTAXY is the name 

 given to the manner 

 in which leaves are ar- 

 ranged on the stem. 

 A careful study of phyllotaxy reveals the important 

 fact that plants adopt every possible means of placing 



Fig. 49. — Akanda {Calotropis giganiea) 



