ORGANS or KEPRODUCTION. 197 



are produced, and these, like those of a branch, are developed 

 in the axil of leaves called bracts, as we have before seen. All 

 the flowers therefore of an Indefinite Inflorescence must be ne- 

 cessarily axillary, and hence such an inflorescence is also termed 

 axillary. The general characters of Indefinite, Indeterminate, 

 or Axillary Inflorescence depend therefore upon the indefi- 

 nite growth of the primary axis, while the secondary, tertiary, 

 or other axes which are developed from it, are terminated by 

 flower-buds. In the Definite or Determinate Inflorescence on the 

 contrary, the primary axis is terminated at an early period by 

 the production of a flower-bud, such an axis has therefore a 

 limit at once put to its growth in an upward direction, and hence 

 the names of Deflnite, Determinate, or Terminal applied to it. 

 Each of these classes of inflorescence presents iis with several 

 modifications, which we now proceed to describe. 



1. IXDEFJXITE, IXDETERMINATE, OK AxiLLART IXFLORES- 



ENCE. — The simplest kind of inflorescence in this class is that pre- 

 sented by such plants as the Pimpernel {Anuyallis arvensia) {fig. 

 371), Money-AYort (Lysi- pig^ 389. 



machia Nummular ia'), in 

 which solitary flowers are 

 developed in the axils of 

 the ordinary leaves of the 

 jDlaut, the primary axis 

 continuing to elongate in 

 an upward direction and 

 bearing other leaves and 

 flowers. The flowers are 

 then saidto be soZ/tarw and ^. „o„ ^t^, i , i ^ . 



.J, ,-,^1 , -^ Fig. 389. Wliorled leaves or bracts and 



axillary. W hen such flow- flowers of Mare's Tail Uiippurui vul- 



ers are arranged in whorls garis). 



round the stem, as in the common Mare's Tail (Hippuris vulgarisy 

 each flower being axillary to a leaf (fig. 389), they are said to 

 be whorled. 



When a number of flowers are developed instead of a single 

 one upon an elongated or depressed axis, which is placed at the 

 extremity of a bi-anch, or in the axil of a bract, a number of kinds 

 of inflorescence arise ; depending upon the extent to which the 

 axis is divided, the mode in which the branching takes place, the 

 comparative lengths of the flowei*- stalks, and otlier subordinate 

 circumstances. It will be convenient to describe these various 

 modifications under two heads. 1st, Those kinds of Indefinite 

 Inflorescence with an Elongated Primary axis, and 2nd, Those 

 with a Shortened or Dilated Primary axis. 



1. Kinds of Indefinite Inflorescence with an Elongated Pri- 

 mary Axis. — These are as follows : — 



a. The Spike. — This is a kind of inflorescence in Avhich the 

 primary elongated axis simplv bears sessile flowers, or flowers 

 o3 



