VIIl] 



CONVOLUTE AND INVOLUTE LEAVES 



61 



In the following the young leaves are so rolled inwards 

 that one margin covers the other (convolute) : 



Blackthorn Plum. 



Fig. 40. 



Fig. 41. 



Fig. 40. Plan-diagram of a bud with spiral, involute, stipulate leaves, 

 the bud-scales of which are stipular, e.g. Apple, Poplar, &c. 



Fig. 41. Diagram of plan of bud of Azalea, showing spiral arrange- 

 ment of bud-scales (reduced leaves) and revolute young leaves. 



In the following the two edges of the leaves are rolled 

 in towards the midrib, the inrolling being such that the 

 upper surface is the concave one (involute) : 



Black Poplar, White Poplar, Apple, Pear, and the 

 leaflets of Walnut and Staphylea (Fig. 40). 



While in the following the edges are similarly in- 

 rolled towards the midrib, but on the opposite surface, 

 so that the lower side of the leaf is concave (revolute) ; 

 see Figs. 37 and 41 : 



Plane Azalea Rhododendron. 



Finally, attention may be directed to cases where the 

 leaves have their surfaces crumpled or folded in other 



