OF THE FULCRA. 1 67 



many genera allied to them, the stipulas are united 

 laterally to the footstalk,/. 116. See Potentilla 

 alba, t. 1384. In all these cases they are extrafo- 

 liacete, external with respect to the leaf or foot- 

 stalk; in others they are intrafoliacea, internal, and 

 are then generally simple, as those of Polygonum, 

 t. 1382, 756, &c. In a large natural order, called 

 Rubiacece, these internal stipulas in some cases em- 

 brace the stem in an undivided tube above the inser- 

 tion of the footstalks, like those of Polygonum just 

 mentioned ; in others, as the Coffee, Cojfea arabica, 

 and the Hamettla patens, Exot. Bot. t. 24, they are 

 separate leaves between the footstalks, but meeting 

 just above their insertion. The Europaean Rubiacecz 

 have whorled leaves, as Asperula, Galium, Rubia, 

 &c. ; but Asperula cynanchica, Engl. Bot. t. 33, has 

 sometimes two of its four leaves so small as to look 

 like stipulas, seeming to form an intermediate link 

 between such as have whorled leaves, and such as 

 have opposite ones with stipulas. The next step 

 from Asperula is Diodia, and then Spermacoce. In 

 the two last the bases of the stipulas and footstalks 

 are united into a common tube. 



Some stipulas fall off almost as soon as the leaves 

 are expanded, which is the case with the Tulip-tree, 

 Liriodendron tidlpifera ; in general they last as long 

 as the leaves. 



The absence or presence of these organs, though 

 generally an indication that plants belong to the 



