ON THE NATURE OF STIPULES 201 



The small primary leaves of the Mistletoe have been 

 mistaken by some authors for stipules. 



Aristolochia elegans, while really exstipulate, has a 

 small cordate, membranous, subsessile leaf in the axil, 

 which resembles a single axillary stipule ; sometimes a 

 pair are present. Close examination shows that this stip- 

 ule-like process is really the first leaf of an axillary 

 axis or bud. It clasps the main axis with its auricles, and 

 has two buds in different stages of advancement lying 

 between it and the petiole of the leaf in whose axil it 

 occurs. The small leaf belongs to the larger and more 

 advanced bud. 



The early unfolding of the first pair of leaves of an 

 axillary bud may often give the appearance of stipules. 

 For instance, in Tutsan (Hypericum ATidroscemum) the 

 leaves are opposite and exstipulate, but the first two 

 leaves of the axillary branch, before any further growth 

 of the bud takes place, stand right and left above the 

 base of each leaf, and by a careless observer may be 

 taken for stipules. 



The genus Lotus (Bird's Foot Trefoil) is quinque- 

 foliate. The lower folioles have been sometimes re- 

 garded as leaflets, sometimes as stipules. Bentham and 

 Hooker, in the ' Genera Plantarum,' say, ' Folia 4-5- 

 foliolata, foliolis integerrimis 3 ad apicem petioli 

 confertis, 1-2 juxta caulem stipulas simulantibus.' 



Speaking of the corresponding organs in Tetragono- 

 lobus, Norman says that they ' par leur structure, leur 



