THE BEECH FAMILY 375 



comment; while the staminate flowers of Quercus are ebrac- 

 teate. The pistillate flowers of beech are two in a head 

 (Fig. 257) which is enclosed in a little cup or cupula ' as it is 

 called, bearing scales or spines on its outer surface. This 

 cup eventuallj' encloses completely the ripening nuts, and 

 when mature splits into four partial valves to set them free. 

 The cupule of chestnuts encloses three flowers, ripens into 

 the spiny bur, and splits sometimes into four valves, and 

 sometimes irregularly. Only one flower is in the scaly cupule 

 of oaks (Quercus), and the single nut which constitutes the 

 acorn is so little covered by the cupule as to make splitting 

 of the cupule unnecessary. 



Evidently the projections of the beech cup, the spines of 

 the chestnut-bur and scales of an acorn-saucer are homolo- 

 gous, as is also the main part of the cupule of each. But where 

 are the bracts? Do the four divisions of the ripened beech 

 cup and chestnut-bur correspond to so many bracts which 

 in the acorn-saucer remain coalesced? In that case the 

 various outgro^rths from the cupule would be regarded as 

 mere projections like the spines on a leaf. This view is held 

 by many botanists. Others maintain that the projections, 

 spines, and scales are the free tips of bracts which have coal- 

 esced by their bases to form the body of the cupule. On this 

 view the cupule would be an involucre of many instead of 

 but four bracts. A third view regards the main body of the 

 cupule as stem, that is to say, as a cup-like development of 

 the secondary peduncle, bearing numerous bracts. Thus 

 regarded, the acorn scales, the beech-nut projections, and the 

 branched spines of the chestnut-bur, are homologized with 

 bracts which are entirely distinct and free from the concave 

 inflorescence-stalk. This last theory seems to be the one 

 most easily reconciled with the facts as they appear in other 

 members of the family as well as in those we have studied. ^ 



' Cu'pule < L. cupula, diminutive of cupa, cup. 



- This is the view adopted in our formulas, i does duty for the axial 

 part of the ultimate inflorescences; //w following shows that it becomes 

 woody and cancave like a perigynous torus; while C 4 shows that it 

 dehisces into four valves; or < that it is indehiscent; and Bi <^ that it 

 bears numerous drj' bracts. The other parts of the formulas should be 

 readily understood from what has preceded. 



