426 RELATION TO ENVIRONMENT. 



III. Arrangement of Flowers, or Mode of Inflores- 

 cence. 



817. Flowers are solitary or clustered. — Solitary fjowers are 

 more simple in their arrant^emcnt, i.e., it i.s easier for us to deter- 

 mine and name tlieir relation to each other and to other parts 

 of the plant. They are either axil/ury, i.e., on short lateral 

 shoots in the a.xils of ordinary fohage leaves, or the}' are terminal, 

 i.e., they are borne on the end of the main axis of an ordinary 

 foliap;e shoot. In either case the}' arc so far separated, and the 

 foliage leaves arc so prominent, they do not form recognizable 

 groups or clusters. The manner of arrangement of flowers on 

 the shoot is called inflorescence, while the group of flowers so 

 arranged is the flower cluster. 



Two rlifferent modes of inflorescence are usuallv recognized 

 in the arrangement of flowers on the stem, (i) The corymbose, 

 or indeterminate inflorescence (also indefinite inflorescence), in 

 which the flowers arise from a.\illar"\' buds, and the terminal bud 

 may continue to grow. (2) The cymose or determinate inflor- 

 escence (also deflnite inflnresccnce) in which the flowers arise 

 from terminal buds. This arrests the growth of the shoot in 

 length. 



There are several advantages to the plant in the different 

 modes of inflorescence, chief among which is the massing of the 

 flowers, thus increasing the chances for effective pollination. 



A. FLOWER CLUSTERS WITH INDETERMINATE INFLORESCENCE. 



818. The simplest mode of indeterminate inflorescence is 



where the flowers arise in the axils of normal foliage leaves, 

 while the terminal laid, as in the florist's smilax, the bellwort, 

 moneywort, apricot, etc., continues to grow. The flowers are 

 solitary and axillary. In other ca.ses which are far niore numer- 

 ous, the flowers are associated into more or less defniite clusters 

 ill which are a iumfl>ci- uf I'ecognizablc t}''[>es. The word l}-pe 

 used in this sense, it shouliJ l)e understood, does not refer to an 



