92 



MANUAL OF BOTANY 



(figs. 84 and 185), as in certain species of Lathyrus, and many 

 other Leguminosje. 2nd. The petiole may become cirrhose, as 

 in Lathyrus Aphaca (fig. 186, v). 3rd. The stipules may 

 assume the form of tendrils ; thus in many species of 87iulax 

 there are two tendrils, one on each side of the base of the 

 petiole (fig. 187), in place of the ordinary stipules. 



Ascidia or Pitchers. — These are the most remarkable of all 

 the anomalous forms presented by leaves. They may be seen 

 in the species of Nepenthes or Pitcher-plants (fig- 188), in the 

 species of Sarracenia or Side-saddle-plants (fig. 189), and in 



Fig. 185. 



Fig. 187. 



Fig. 186. 



Fig. 185. Leaf of a species of Lathyrus, showing a winged petiole, with two 



half -sagittate stipules at its base, and termioated by a tendril. Fig. 186. 



A portion of the stem of Latliyrus Aphaca, with stipules, s, s, and cirrhose 



phyllopodium, v. Fig. 187. A portion of the stem of Smilax, hearing a 



petiolate leaf, and two tendrils in place of stipules. 



many others. In the Sarracenia (fig. 189), the pitcher appears 

 to be originated much as is the peltate leaf; by further basal 

 growth it becomes tubular. In the Nepenthes (fig. 188), the 

 petiole is winged for a certain distance, then assumes the ap- 

 pearance of a tendril, and ultimately bears a pitcher, p ; this is 

 arched over by a lid, I, called an operculum, which is united to 

 it by an articulation. 



Eqiiiiant Leaves. — A peculiar form of leaf is seen in Iris, 

 Phorminm, and certain other Monocotyledonous plants. The 

 leaf is long and comparatively narrow, and its flattened sur- 



