346 



DICOTYLEDOXES. 



the four valves in the cupule of Castanea are considered as 

 bracteoles of the lateral flowers of the dichasium) ; according to 

 another view (see Prantl, in Bugler's Bot. Jahrb., viii., 1889), it is 

 a ring-like axial outgrowth independent of the bracteoles of the 

 flower, whose scales arid spines are floral-leaves. The cupule in 

 the Oak onlj encloses the base of the fruit, but in the Eating- 

 chestnut and Beech the fruit is completely enclosed, and con- 



FIG. 332. Cnslanea vesca : A branch with inflorescences; B d -flower; C young cupule 

 with three 9 -flowers; D $ -flower; E the same in longitudinal section; F cupule with 

 3 nuts (diminished) ; 6f, H nuts (G in longitudinal section to shove embryo). 



sequently the cupule must divide into a number of valves (gener- 

 ally 4) to allow the fruit to escape. In the 3-flowered dichasia 

 of Pasania, Sect. Eupasania (Trop. Ind.), each individual flower 

 has its own cupule of the same structure and development as in 

 Qnercus, and, moreover, each group of flowers has externally the 

 typical six bracteoles. 



Castanea (Eating-chestnut, Fig. 332). The catkins are erect 



