BRITISH FLOWERING PLANTS 



when it has small acute indentations and rounded 

 projections (fig. 34), dentated when it has obtuse 

 incisions and pointed projections (fig. 35), sinuated 

 when it has obtuse incisions and rounded pro- 

 jections (fig. 36), ciliated when the margin is set 

 with fine hairs (fig. 37), incised when the margin 



When the veins run straight they are called 

 parallel (figs. 39 and 40), but they are frequently 

 curved. Reticulated leaves are called digitate 

 when equally thick veins subdivide towards the 

 ends (fig. 41), and pinnate when there is one 

 midrib forming a continuation of the leaf-stalk, 



exhibits alternately larger; and smaller indentations 

 and projections (fig. 38). 



On examining a leaf we find that the softer 

 surface is traversed by hard lines, which are 

 called veins or nerves, and which may be either 

 simple or branched, and sometimes form a 

 network. 



and throwing out slender branching veinlets on 

 the sides (fig. 42). 



Hitherto we have been speaking of simple and 

 undivided leaves, but many plants exhibit leaves 

 more or less divided. 



When the division is incomplete the leaf is 



