194 



BUDS AND STIPULES 



SI 



As AN ASSISTANCE IN CLIMBING 



There are two ways in which stipules may assist in 

 this respect, viz. (1) by being developed into tendrils, 

 or (2) into more or less reversed spines. 



The case of the tendrils of Smilax 

 is one which has occasioned much 

 discussion, but I agree with Tyler 

 (24) that the embryological, together 

 with the anatomical, characters in- 

 dicate that in Smilax the tendrils 

 are true stipules, found in connection 

 with the sheathing petiole. 



In Paliurys amtralis (fig. 313), a 

 Southern European plant belonging 

 to the same family as our Buckthorn, 

 the stipules are spiny, but the two 

 stipules of each leaf are different in 

 form and serve for different purposes. 

 Those on the upper side of the shoots 

 are long, subulate, and straight; 

 FIG. 313 PALIUBUS those on the lower side are shorter 



AUSTRALIS. PoBTION Tin 1 mi 



OF A SHOOT. and denexed. The former appear 



to serve as a P rotection a S ainst 



browsing quadrupeds ; while the 



B 



Sc' 



scar of fallen petiole ; . , , 



sc'", the third scar in hooked ones also assist the plants 



the order of arrangement, 



showing that the phyi- to c li m b or scramble up among other 



lotaxy is \. Nat. size. 



shrubs and bushes. 

 In MaelioeriwM. also, a tropical American genus of 



