16 



COMPOUND LEAF 



[CH. 



of Ailanthus glandulosa or of the Horse-chestnut is com- 

 pound. 



The distinction rests rather on the jointing or articu- 

 lation of the parts in the compound leaf, and we may 

 generally employ this criterion as a test. The compound 

 leaf, then, has the segments or branches (leaflets) of the 

 lamina articulated more or less distinctly to the common 



Fig. 4. Falling leaves of Horse-chestnut, ^Esculus, showing disarticu- 

 lation of leaflets from rachis (K). 



leaf-stalk (rachis) and devoid of any trace of lamina at 

 the place of junction, and these leaflets can therefore be 

 pulled away easily, leaving a scar where they were joined. 

 This is readily detected when such compound leaves fall 

 in the autumn, each segment coming off separately and 

 leaving a distinct scar (Fig. 4). 



