LECT. IX.] GENERAL FIGURE OF LEAVES. 487 



It is arrow-shaped (sagittatum), y., when the disk 

 is triangular, and the sides are produced down- 

 wards into two pointed lobes, like a barbed ar- 

 row: and halberd-shaped (hastatum), z. 1., when 

 the sides are produced into two lateral spread- 

 ing points or lobes near the base. Sometimes the 

 lateral lobes are distinct, as represented at z. 2, 



A leaf is heart-shaped (cordatum), a., when 

 it is hollowed at the base into two lobes and 

 pointed at the apex, so that the leaf has some- 

 what the appearance of the heart on a card. 

 When the apex 5 instead of being directly oppo- 

 site to the base, is thrown off at one side, the leaf 

 is said to be oblique cordatum, , as beautifully 

 illustrated in Begonia. Kidney-shaped (reni- 



n4 



