188 



THM LEAF 



fine and produced in the form of bristles they are called Spinulose (Fig. 

 524). 



When a margin shows indications of being dentate, serrate, or crenate, 

 but the teeth are not distinctly pronounced, the adjective Ob scurely 

 is prefixed. For this word that of "Obsoletely" is substituted when 

 the leaf possesses a relationship such as to make it probable that its 

 ancestral forms were more strongly characterized by this condition 

 (Fig. 532). 



Fig. 538. Pinnatifid (Pedicularis) . 539. Palmatifid (gooseberry). 540. Laciniately divided (but- 

 tercup). 541. Slightly revolute. 542. Strongly re volute (TJosmannus). 543. Lobed, the lobes acute, 

 the sinuses obtuse (Quercus). 544. Both lobes and sinuses obtuse {Sassafras). 545. Lobes obtuse, 

 sinuses acute {Hepatica). 546. Incisely parted {Geranium). 



When the teeth and their sinuses are all connected in such a way 

 that the margin represents a wavy line, the latter is called Repand or_ 

 U ndulate, or Sinuate (Figs. 536 and 537). When a leaf is so deeply 

 toothed that the sinuses reach well toward the middle portion (Figs. 

 543 to 545) the term _^Lobed is s ubstituted for those above defined. 



When the division, by a sharp sinus, extends more than half-way to 

 the middle, yet not very near to the midrib, it is called Cleft ( Fig. 539). 



When reaching almost to the midrib (Fig. 538) or to the base in case 

 of a digitate leaf (Fig. 546), it is called Parted, {[ nd when all the way, 

 DividedJFigs. 540 and 559). The divided leaf is, however, not the same 

 as the compound leaf, inasmuch as the separation of its blade into 

 distinct leaflets is not complete. (Compare Figs. 547 and 555.) 



The cleft, parted or divided leaf, is either Pinnatifid(Figs. 538, 556, 



