xxvni] 



STEMS 



11 



sometimes show transverse rings on the bark marking the position 

 of former terminal buds, and in older trunks these may disappear, 

 leaving a fissured bark^. In Cycas siamensis the tuberous stem 



Pig. 382. Encephalartoa OhelUnckii. (tV nat. size.) 



is similarly covered with a rough bark (fig. 383) and the stems 

 of Zamia are also characterised by an absence of persistent leaf- 

 bases (figs. 381, B; 395, la, a). It is pertinent to remind the 



1 CaldweU (07). 



