XV] CUPULE, "HUSK," ETC. 143 



bracteoles {aa'^/3' in Fig. 35, C) subteuding as many as 

 seven male flowers, each composed of a six-lobed bell- 

 shaped perianth containing about a dozen stamens, and 

 often with a central rudiment of an aborted ovary. Close 

 investigation shows that we have here a cymose cluster 

 of male flowers, in the axil of the bract. 



Similar dissection of a cluster of female flowers 

 (Fig. 35, E) shows that the bract bears in its axil a group 

 of three female flowers, surrounded by a common thick 

 investment somewhat prickly on its outer sides, and 

 subtended below by two lateral bracts (a and ^ in 

 Fig. 35). 



Each female flower shows a flask-shaped ovary, 

 chambered into about six loculi and bearinsf above the 

 same number of stigmatic arms. Around the base of 

 the stigmas there are also an equal number of sepal-like 

 segments, constituting an epigynous perianth : i.e. the 

 ovary is inferior. There are no stamens in the normal 

 case (Fig. 41). 



Here then we have a cluster dichasium of three 

 female flowers with an epigynous perianth. Consequently 

 the investing prickly structure cannot be the perianth : 

 what is it ? 



The comparative morphology of numerous other cases 

 shows that we must regard it as a special investment of 

 the inflorescence, and it is termed the Cupule. It is 

 essentially the same organ as occurs in the Hornbeam as 

 a leafy trilobed, bract-like structure investing the fruit, 

 and as the " Husk " of the Filbert, and the " Cup " of the 

 Acorn ; the cupule of the Beech invests two flowers, that 

 of the Oak one. Further particulars will be found in each 

 case in Part 11. The essential points to notice here are, 

 the increasing complexity of the catkins and of the in- 

 vesting structures, and the epigyu}' of the female flowers. 



