426 RELATION TO ENVIRONMENT. 



III. Arrangement of Flowers, or Mode of Inflores- 

 cence. 



817. Flowers are solitary or clustered. Solitary flowers are 

 more simple in their arrangement, i.e., it is easier for us to deter- 

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

 of the plant. They are either axillary, i.e., on short lateral 

 shoots in the axils of ordinary foliage leaves, or they are terminal, 

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

 foliage shoot. In either case they are so far separated, and the 

 foliage leaves are 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 different modes of inflorescence are usually recognized 

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

 or indeterminate inflorescence (also indefinite inflorescence), in 

 which the flowers arise from axillary buds, and the terminal bud 

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

 escence (also definite inflorescence) 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 bud, as in the florist's smilax, the bellwort, 

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

 solitary and axillary. In other cases which are far more numer- 

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

 in which are a number of recognizable types. The word type 

 used in this sense, it should be understood, does not refer to an 



