MORPHOLOGY OF REPRODUCTIVE ORGANS 119 



which have alternate leaves, as for instance in the species of 

 Bcmtimculus {fig. 221). In definite inflorescences the flovs^er- 

 buds necessarily follow a different order of expansion from 

 those of indeiinite inflorescences. In them the terminal flower 

 is the oldest and conseqviently 

 the first developed {fig. 227, 

 /'), and other flower-buds 

 are produced in succession, 

 either from the apex towards 

 the base of the axis, if the 

 latter is elongated, /" /"'; 

 or from the centre towards 

 the circumference, if it is 

 shortened or dilated. The 

 uppermost flower-bud of the 

 elongated primary axis {fig. 

 227,/'), and the central one 

 of the shortened or dilated 

 axis, open first ; and the ex- 

 pansion of the other flower- 

 buds proceeds in succession 

 downwards, or towards the 

 circumference, according to 

 the character of the primary 

 axis. Such an order of expan- 

 sion is called centrifugal. 

 Hence, whUe the indefinite 

 kinds of inflorescences are 

 characterised by an acropetal 

 or centripetal order of expan- 

 sion, those of definite inflo- 

 rescences are centrifugal. 

 The name cyme is often given 

 to many-flowered inflorescences of this type. 



Fix/. 227. A plant of Ranunculus bulbosus. 

 a\ a'. Primary axis terminated by a fully 

 expanded flower, /. a". Secondary axis, 

 whicli is also terminated by a flower, /", 

 not so fully developed as/', a'". Tertiary 

 axis terminated by a flower-bud, /'", 

 which is less developed than/' and/". 



A. Forms of Cymose Inflorescence with no Pseud-axis. 



a. The Solitary Terminal or Axillary Flower. — The simplest 

 kind of inflorescence of the cymose type is that presented by 

 such plants as the Pimpernel {fig. 192), in which solitary flowers, 

 6, &, are developed in the axils of what are commonly regarded 

 as the ordinary foliage leaves of the plant, a, a. The primary 

 axis of the plant bears thus several secondary axes, each ending 



