136 AN INTRODUCTION 



fleshy, obtuse, convex underneath, and often with a 

 cartilagmeous margin. 



Triquetrous, three- cornered ; when they are su- 

 bulate ; and have three flat longitudinal sides. 



Sulcate, furrowed ; when they are scored longitu- 

 dinally with numerous angles or ridges, and as many 

 hollows or channels betwixt them. 



Carinate, keeled ; when the prone part of the disk 

 is prominent longitudinally. 



M embranaceous ; when they have no perceptible 

 pulp between the two surfaces. 



CHAP. VI. 



OF COMPOUND LEAVES, 



A LEAF is said to be compound, when there are 

 rnore than one upon a petiole or footstalk. 



COMPOUNP leaves are to be considered in respect 

 to Structure and Degree. 



By the STRUCTURE of a compound leaf is to be 

 understood the insertion of the folioles or lesser 

 leaves of which it is compounded ; and in this re- 

 spect leaves are called, 



Compound when a single petiole furnishes more 

 than one leaf. 



Articulate, jointed ; when one leaf grows out at 

 the top of another. 



Digitate, fingered; when the apex of a single pe- 

 tiole connects many folioles : And they are termed 

 Binate, Terns f e, or Quinate, growing two, three, or 

 five togetner, according to the number of folioles, of 

 which the digitate leaf consists. 



Pinnate, winged ; when the sides of a single pe- 

 tjp}e connects many foiioles, 



