



THE LEAVES OF PODOPHYLLUM 



J. Arthur Harris 



An inspection of the leaves of the flowering stem of Podophyllum 

 pdtatum shows that they are not exactly the same size. Furthermore, 

 the larger one seems generally to be inserted a little lower on the axis 

 than the other of the pair. Holm (3) found that the two leaves do not 

 develop simultaneously but that one appears before the other. Con- 

 cerning this point he writes: 



Of its two leaves, the one is developed earlier than the other. The base of the 

 petiole of this leaf is dilated into a pair of broad wing-like stipules which envelop 

 each other and enclose a small green leaf and a flower bud; thus the two green 

 leaves did not develop at the same time, as it might seem when we examine the 

 plant during its flowering period with its leaves apparently opposite. 



Some of the teratological literature has an interesting bearing upon 

 this question of the differentiation of the leaves. Porter (8) illus- 

 trates one type in which the flowering stem bears two leaves, the 

 peduncle apparently originating from one of the petioles two or more 

 inches above their insertion. In another form there are three peltate 

 leaves with the peduncle originating between the upper two, which 

 are represented as about equal in size and opposite, 1 or some distance 

 above the fork from one of the petioles. One of the leaves may be 

 much reduced in size, or but one leaf— then apparently terminal and 

 with the peduncle lateral— may appear. Finally both leaves may be 

 absent. Foerste (2), apparently unacquainted with Porter's 

 paper, redescribes these forms and adds other types, similar in a 

 general way. The production of a small, not peltate lamina upon the 

 peduncle is not very rare. The instance observed by Bailey (i) 

 of a flower replaced by a small erect leaf, and mentioned by Penzig 

 (7) as sehr wunderlich, was probably merely due to the early abortion 

 of the flower bud in such a case. 



The essential point to be gained from the foregoing observations 

 is that the flowering stem of Podophyllum, instead of producing only 

 two opposite leaves, may become an elongated shoot of at least three 



1 Here probably belongs the case described by Trimble (9) which Penzig (7) 

 records as not clearly expressed. 



Botanical Gazette, vol. 47] [43 8 



