OKGANS OF EEPEODUCTIOX. 



187 



In some cases the peduncle becomes flattened and assumes the 

 form of a phyUode, in which case it is called a phylloid pe- 

 duncle or pedicel. Examples of this occur in the Butcher's- 

 Broom {Ruscus aculeatus) {fig. 383), where the flowers arise 



Fig. 382. 



Fig. 383. 



Fig. 382. Female plant of VaUisneria spiralis, vrith its flowers arranged on 



spiral peduncles. Fig. 383. Portion of a branch of the Buccher's- 



Broom (^Ruscus aculeatus), with phylloid pedicels bearing flowers, a. 



from its surface, and in Xyloiphylla, in which the flowers are 

 attached to its margins. Sometimes the peduncle, or several pe- 

 duncles united, assume an irregular flattened appearance, some- 

 what resembling the fasciated branch already described, (see page 

 100), and bear numerous flowers in a sort of crest at their ex- 

 tremities, as in the Cock's-comb. 



In speaking of the branches of a stem, we found that in some 

 cases, instead of arising in the axil of leaves, they become extra- 

 axillary, in consequence of adhesions of various kinds taking 

 place between them and the stem, &c. In like manner the 

 peduncle may become extra-axillary by contracting adhesions. 

 Thus, in the Lime tree {Tilia europaa) {fig. 384), the peduncle 

 adheres to the midrib of the bract for some distance, and then 

 becomes free. In many Solanacese {fig. 385), the peduncle also 

 becomes extra-axillary by forming adhesions to the stem in 

 various ways, 



"With respect to their duration the pedtmcle and pedicel vary. 

 Thus, they are said to be caducous, when they fall off soon after 

 the opening of the flower, as in the staminate or male flowers 

 of a catkin ; they are deciduous, when they fall off after the 

 fruit has ripened, as in the Cherry ; they are persistcrit if they 

 remain after the ripening of the fruit and dispersion of the seed, 

 as in the Dandelion ; or if they enlarge or continue to grow 



