GM03S ANATOMT OP FLOWElllJUQ PLANTS, xix 



wedge-shaped {cuneiform) leaf. In some cases a point or bristle 

 grows from the obtuse apex; such are said to be mueronate. 



The extremity when indented is notched or emarginate ; when 

 this is slight it is retuse; when so deep from the apex as to appear 

 cleft the leaf is lifld. A common form of emarginate apex is seen 

 in the dbcordate (i.e., inversely heart-shaped) leaf, while the emar- 

 ginate base is found in the cordate (i.e., heart-shaped) leaf. The 

 notch in the base of a leaf is also known as a sinus. 



Margin of the Blade. — When the growth of the leaf has been 

 'iniform throughout, its margin is an even and continuous line, 

 and the blade is said to be entire. More commonly there are 

 inequalities in the growth; when these are rounded and not great 

 the margin may be waiiy, or if somewhat more, sinuate, which 



Fio. XVI.— Diagram showing the principal forms of margin. 



readily passes into the Idbed form, with the projections Qdbes) and 

 the indentations (sinuses) both rounded. (Fig. XVI.) 



In some cases the projections alone are rounded, the sinuses 

 being narrow as if cut. When such projections are small the 

 blade is said to be crenate (scalloped) ; when they are large, cleft- 

 lobed, or cleft. (Fig. XVI.) 



When the projections are pointed and small the blade is said to 

 be serrated (saw-toothed) ; when larger and standing out from the 

 margin, dentate (toothed) ; wlien still larger, incised. (Fig. XVI.) 

 When the projections are hardened and sharp-pointed tht leaf is 

 spiny. 



Venation of the Blade. — The framework of fibro-vascular 

 bundles (veins) running through the leaf always conforms to the 



