CHAPTER V 



THE REPRODUCTIVE STRUCTURES: THE FEMALE 

 CONE AND THE FEMALE GAMETOPHYTE 



Cycad plants are strictly male and female, cones of 

 both sexes never being borne upon the same individual 

 (Fig. 32). Even in branching specimens cones on all 

 the branches are of the same sex; and plants developed 

 from buds are of the same sex as the main axis. 



The conspicuous reproductive structures are the 

 cones. The female cone produces spores, called mega- 

 spores; and the male cone produces smaller spores, 

 called microspores. The megaspore upon germination 

 produces a "female gametophyte," which finally gives 

 rise to eggs; and the microspore produces a "male 

 gametophyte," which gives rise to sperms. 



THE FEMALE CONE 



The female cone of the cycads, called the seed- 

 bearing cone, the ovulate cone, or the ovulate strobilus, 

 is borne at the apex of the stem, or is lateral just below 

 the apex. Usually the cones are borne singly, but 

 occasionally two or three are found, especially in Macro- 

 ' zamia and Encephalartos. 



Some of the female cones are the largest known in 

 either living or extinct plants. The cones of Encepha- 

 lartos caffer and E. AUensteinii frequently attain a 

 weight of more than forty pounds when two or three 

 are borne at the same time. In the botanical garden 



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