BLACK: INFLORESCENCE AND FRUIT OF PYRUS MALUS 525 



described as occurring on short, woolly peduncles. Sargent (16) in 

 his Manual of the Trees of North America states that the flowers 

 occur in simple terminal cymes with filiform deciduous bracts and 

 bractlets. In North American Trees by Britton (17) the flowers 

 are said to be clustered in simple, terminal cymes on stout, woolly 

 pedicels. In Britton and Brown's (18) Flora of the Northern 

 United States, the flowers are described as borne in simple, terminal 

 cymes upon pedicels. 



In Gray's Structural Botany (4) the inflorescence is divided, 

 according to kind, into Determinate and Indeterminate. In a 

 determinate flower cluster, the axis is terminated by a flower 

 which corresponds to a terminal bud. If more flowers appear they 

 spring from axils, preferably from the highest axils and develop 

 later. The order of evolution is indicated by the size of the flower 

 buds. This type of inflorescence is also called Cymose and in 

 a cymose cluster the flowering is centrifugal or descending. The 

 terms corymbiform cyme, corymbed cyme, and umbel-like or 

 umbelliform cyme originate in combining qualities of indeterminate 

 inflorescences with determinate. The corymb and umbel are both 

 examples of the indeterminate inflorescence and differ chiefly in 

 the length of the axis or peduncle and the equality or inequality 

 of the pedicels. 



The words peduncle and pedicel have been used interchangeably 

 as will be observed in the above descriptions. A peduncle is the 

 general name of a flower stal or branch directly terminated by a 

 flower. The name is also given to a more or less branched flower- 

 ing axis, the ultimate divisions of which are called pedicels. The 

 term pedicel is given to distinguish a partial flower stalk or, more 

 strictly, the stalk of each individual flower of an inflorescence. In 

 LeMaout and Decaisne's (19) Descriptive and Analytical Botany, 

 the following definition of an inflorescence is found. ^ "An 

 inflorescence in its restricted sense consists of a group of pedicelled 

 flowers, bracteate or not, all springing from a common peduncle 

 which bears no true leaves." 



Upon dissecting the inflorescence of the apple as shown in 

 PLATE 34, FIGURE 4, each lateral flower is found in the axil of a 

 leaf or bract. The lower flowers are in the axils of leaves and 

 the upper are found in the axils of modified structures, or bracts, 



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