. Botany of the living plant. Botany. 224 BOTANY OF THE LIVING PLANT flowers which bloom during a prolonged period, instead of simul- taneously. These are among the biological advantages gained by complicated inflorescences. The characteristic features \vhich inflorescences show depend upon four main factors : (i) the arrangement of tlie leaves (bracts) in the axils of which the branches arise ; (ii) the proportion of intercalary growth of the several axes ; (iii) the number of flower-buds produced ; and (iv) the succession in which the buds mature. Of these the most important is the last, and
. Botany of the living plant. Botany. 224 BOTANY OF THE LIVING PLANT flowers which bloom during a prolonged period, instead of simul- taneously. These are among the biological advantages gained by complicated inflorescences. The characteristic features \vhich inflorescences show depend upon four main factors : (i) the arrangement of tlie leaves (bracts) in the axils of which the branches arise ; (ii) the proportion of intercalary growth of the several axes ; (iii) the number of flower-buds produced ; and (iv) the succession in which the buds mature. Of these the most important is the last, and inflorescences may be classed according to its consequences as Definite or Indefinile. If a distal flower blooms first that will stop the apical growth. f ^^M^ V" n Fig. 170. DLigrams of common types of Inf3oresccnce. A, B, definite ; C, D, E, indefinite. The numbers indicate the succession of the flowers. See text. of the main axis, and all further flowers must be borne on lateral axes. Such inflorescences are termed Definite, or Cymose (Fig. 170, A, B], They com- monly develop sympodially, that is, the lateral axes grow so as to overtop the main axis. But if the buds on lateral branches bloom first, the apex may still continue to grow, and to form additional bracts and flowering buds. Such inflorescences are called Indefinite, or Racemose (Fig. 170, C, D, E). They usually work out along monopodia! lines, that is, the main axis remains dominant, and the lateral axes are accessor)-. The simplest Cymose or Definite inflorescence is illustrated by the Tulip, with its solitary flower terminal on the peduncle, or main flower-stalk. But in the bulb below, an axillary bud matures during the season, which will repeat the flowering axis in the next year, and so on. The Tulip is then a deflnite inflorescence, with an interval of a year between its flowers. Its branch-system is sympodial, each succeeding axis overtopping its Please note that these images are extracted
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