igi6] HOFFSTADT— PIPER METHYSTICUM 127 



able, cells next to the cambium do not lignify and remain active. 

 These are also scattered at irregular intervals throughout the ray. 

 In section this gives the ray an irregular banded appearance (fig. 18). 

 There are no growth rings. Much of the wood parenchyma 

 touching the pith retains its activity at the node and divides long 

 after secondary wood has been laid down. This pushes the pri- 

 mary vessels of the bundles apart at great distances, as well as the 

 cells of mechanical tissue (fig. 18). 



The stem when young is packed with starch and piperin. 

 Mucilage cells are scattered throughout it, and the buds especially 

 are covered with mucilage. 



Leaves 



The leaves have distinct petioles, the sheathing bases of which 

 extend entirely around the stem, which becomes narrow opposite 

 the point of insertion of the leaf. The leaf traces vary in number 

 from 7 to 14. The bundles may be of two sizes. The lower part 

 of the petiole is flattened on one side; the upper part is circular. 

 The bundles form a crescent in the lower portion of the petiole 

 (fig. 21), this crescent being made complete in the upper portion by 

 the branching of the bundles at the points of the crescent (fig. 14). 

 The secondary bundles form a more or less complete outer ring, 

 are of the same type as those of the stem, and anastomose at 

 any portion of the petiole. Union of the primary and secondary 

 bundles, however, takes place before the traces enter the blade, 

 which has 7-9 strong palmate veins, the 3 median ones running 

 parallel for a while before they swing out laterally. The vernation 

 of the leaf is involute. 



Branching 



Buds are borne in the bases of the sheathing petiole, the number 

 varying from 1 to 3. The appearance of a single bud is often to 

 one side instead of in the median position, which probably accounts 

 for the appearance of branches coming from the side of the leaf. 

 The buds are invested by a large amount of mucilage. The 

 central bundles of the branch connect with those of the stem, and 

 the peripheral ones connect with the peripheral bundles of the 



