THE MORPHOLOGY OF WEEDS 



121 



a wedge-shaped leaf ; cordate, leaf with a wide and round- 

 ed base, forming a notch where the petiole is attached ; 

 reniform or kidney-shaped leaf, like the leaf of wild 

 ginger; auricidate, leaf with a pair of small blunt pro- 

 jections at the base; 

 sagittate, like an auricu- 

 late, but the projections 

 are sharp, as in sagitta- 

 ria; hastate, like the 

 last, but with lobes 

 pointing outward; pel- 

 tate, the petiole at- 

 tached to the lower 

 surface, like the man- 

 drake ; acuminate, the 

 apex of leaf prolonged 

 into a tapering point; 

 acute, where the leaf 



Fig. 46. Two types of parallel-veined 

 leaves. 



ends in a sharp point 



rather abruptly; ob- 

 tuse, where the leaf 

 has a blunt or 

 rounded apex ; mu- 

 cronate, where the 

 apex of the leaf is 

 tipped with a small 

 and short point ; 

 truncate, with the 

 end as if cut off 

 square ; retuse, where 

 the summit of the 

 leaf has a small 

 notch ; emarginate, 

 with a decided 

 notch ; obcordate, the reverse of cordate, the upper end 

 larger, like the leaf of white clover; cuspidate, leaf with a 



Fig- 47- 

 (Dudgeon.) 



Lobed leaf 



sassafras. 



