10 ASCENDING PART. HERBAGE. 



35. Their insertion is either sessile or stalked; peltate, 

 clasping, connate, perfoliate, sheathing, equitant, or 

 decurrent. 



36. Their form is simple, or compound in various de- 

 grees ; undivided, or lobed ; their outline very va- 

 rious in different plants; sometimes different on the 

 same individual. The lower leaves of water plants, 

 the upper of mountain ones, have commonly the 

 greatest tendency to be much divided. For their 

 particular forms see Introduction to Botany. 



37. Foliola, Leaflets, are the partial leaves, which, con- 

 nected by one common, simple or branched, foot- 

 stalk (23), make a compound leaf. 



38. The margin of Leaves or Leaflets is either entire, 

 wavy, serrated, jagged, toothed or notched, in a sim- 

 ple or compound manner ; naked, fringed, spinous, 

 cartilaginous, glandular ; flat, revolute (rolled back- 

 ward), or involute (the reverse). 



39. Their surface is smooth, naked, glaucous, downy, 

 hairy, woolly, warty, glandular, or prickly ; even, 

 rugged, or blistery ; veiny, ribbed, or veinless ; co- 

 loured, variegated, opaque, or polished. Their ribs 

 and veins contain the principal sap-vessels. 



40. Some Leaves are fleshy, cylindrical, semicylin- 

 drical, awlshaped, tumid, channelled, keeled, two- 

 edged, hatchet-shaped, solid, or hollow. 



4 1 . Others are membranous, leathery, rigid, or almost 

 woody. 



42. The termination of Leaves is either obtuse^ acute, 



