THE LEAVES. 



29 



(foliola). The petiole of a compound leaf is the common petiole (p. communis], and 

 that of each leaflet is a petiolule (petiolulus). 



m 



109. Maple. Palmately-lobed leaf. 110. Turnip. Lyrate leaf. 112. Chelidonium. Pennilobed leaf. 



A leaf is simply compound, wlien the leaflets, whether petiolulate or not, spring 

 directly from the common petiole ; and, according to its nervation, the leaf is 



111. Hellebore Pedateleaf. 113. Herb-Robert. Palmatisect leaf. 114. Robinia. Pinnate leaf. 



pinnate (/. pinnatum, Robinia, fig. 114) or digitate (/. digitatum, Horse-chestnut, 

 fig. 115 ; Lupin, fig. 116). When there are but few leaflets, their insertion must 



