82 WRIGHT : THE GENUS DIOSPYROS 



is very great, and though it is easy to connect the flowers oi f 

 the third class in the polygamous group with those of the 

 true male, it is not so easy to connect the hermaphrodite 

 flowers of the polygamous group with the ordinary female 

 flowers. 



We have again to realize that in the same species there is 

 a wide variation in the number and orientation of the floral 

 parts of male and female flowers. 



Dioecious, Monoecious, and Polygamous. This may occur 

 in flowers of D. hirsuta, D. Thwaitesii, and D. Ebenum. 



In these species a very complicated sex relationship 

 exists. If we take as our example D. Thwaitesii, we find 

 that three types of trees exist. 



In the first place there are pure female trees. Here the 

 flowers may occur solitary or in small sessile axillary 

 clusters of two to seven flowers, each component having 

 five staminodes disposed so as to alternate with the five 

 lobes of the corolla and a four-celled ovary. 



In the second class there are pure male trees having the 

 flowers in axillary groups of four to fifteen. Each flower 

 has ten stamens arranged in five pairs alternating with the 

 corolla lobes, or several pairs and the remainder single, 

 arranged irregularly or as five series. In these flowers the 

 pistil is always rudimentary, and consists of nothing more 

 than a central mass of brown hairs. It is in the third class 

 of trees that complicated relations exist. In this class we 

 have the true male and true female flowers occurring on 

 the same tree, sometimes in separate axillary groups of the 

 same branch, and at other times in the same axillary group. 

 Thwaites noted that in D. hirsuta the female flowers were 

 sometimes mixed with the male. We may therefore speak 

 of the monoecious condition in these species. But in 

 addition to the monoecious condition we may have on the 

 same tree a truly polygamous group or groups of flowers 

 exactly analogous to the polygamous flowers described for 

 D. Gardneri, D. sjlyatica, and others. The polygamous 



