78 



BOTANICAL GAZETTE 



[JULY 



central portion of the stele is occupied by large unlignified cells 

 which are slowly thickened into metaxylem. The phloem seems 

 to arise irregularly near the periphery and is not easily recognized 

 when young. In the young shoot examined, the stele became radial 

 toward the base (fig. 22). Here there were fewer protoxylem 

 points also, 3 or 4 in number, and part way up the stem there was 

 an isolated xylem strand as occurs in L. Billardieri (fig. 19). The 



Fig. 23. — L. Holstii: transverse section of mature stem, showing parallel-banded 

 type of stele; phloem scattered irregularly between the xylem bands; px, protoxylem; 

 p, phloem; X185. 



distinctly 



il arrangement extende 

 the main plant, 

 mature vegetative stem 



from 



banded type of stele (fig. 23) rr 



described for L. verticillatum, and more developed than those in the 

 strobilus of L. carina turn. 



mature 



tered in patches throughout the parenchyma bands between the 

 xvlem srouDS. 



