GLOSSARY 387 
STOMA (pi. STOMATA) : an epidermal organ for regulating the communi- 
cation between green tissue and the air. 
STROBILUS : a cone-like cluster of sporophylls. 
STYLE: the stalk-like prolongation from the ovary which bears the 
stigma. 
SYMBIONT : an organism which enters into the condition of symbiosis. 
SYMBIOSIS : usually applied to the condition in which two different 
organisms live together in intimate and mutually helpful relations. 
SYMPETALOUS : applied to a flower whose petals have coalesced. 
SYNCARPOUS : applied to a flower whose carpels have coalesced. 
ZOOSPORE : a motile asexual spore. 
ZYGOTE : the sexual spore resulting from conjugation. 
