374 



NATURAL HISTORY OF PLANTS. 



fhree of the sepals.' The filaments are free, inserted at the base in 

 a large hypogynous disk relatively to which they are more or less 

 interior or exterior, and the anthers are bilocular, introrse, dehiscent 

 by two longitudinal clefts.^ The gynseceum, rudimentary in the male 

 flower, is formed by a free bilocular ovary compressed perpendicu- 

 larly to the dividing partition of the two cells, surmounted by a 



Acer coedneum. 



Fig. 421. Male 

 inflorescence. 



Pig. 423. Female inflorescence. Fig. 424. Female flower. Fig. 422. Male flower. " 



style immediately divided into two long branches stigmatiferous 

 withia and above. In the internal angle of each ceU are 

 inserted two ascendent ovules, incompletely. anatropal, whose micro- 

 pyle ^ is finally directed downwards and outwards, and the lulum 

 soon produces a large axUlary expansion more or less surrounding 

 the seed. The fruit is a double samara with two cells,* whose wings 

 are formed by the development of the backs of the carpels ; these cells 

 separate finally from each other and contain one or two seeds, having 

 under their coats a conduplicate embryo, with thin and narrow coty- 

 ledons, irregularly plaited or convolute, and an elongated inferior 

 radicle. In certain Maples the flowers are apetalous ; in others 4-1 2- 

 merous. In others again, like Acer Negundo (fig. 426), of which 



' Payer, loo. cit. 125. According to this 

 author the two stamens superposed to the same 

 sepal are not both of the same age. 



^ According to H. Mohl. {Ann. So. Nat. s&. 2, 

 iii. 337), the poUen is " ovolde, trois plis; dans 



I'eau, sphlrique aveo trois larges bandes {A. 

 platanoides campestre, dasycarpum, monspeasula- 

 nmn, Psmdoplatanm)," 



3 With double coat. 



* Sometimes with three or moi:e cells. 



