Any flowering system consisting of more than one flower. It is usually separated from the vegetative parts by an extended internode, and normally comprises individual - flowers, bracts and peduncles, and pedicels. The change from vegetative to reproductive growth may be triggered by photoperiod or temperature and is thought to be hormonally controlled (see florigen
). The arrangement of flowers into inflorescences is believed to have evolved from solitary flowers. The increase in flower number has been accompanied by a decrease in the size of the individual flowers, and specialization for different roles. Development of inflorescences may terminate vegetative growth (see definite growth
) or allow it to continue (see indefinite growth
). The type of growth habit has considerable economic implications in such crops as the grain legumes where it directly affects total crop yield, and sequence and time of fruit ripening.
Inflorescences are classified morphologically by their branching behaviour into *cymose inflorescences
, where the apical meristem differentiates into a flower and new growth is from the axils, and into *racemose inflorescences
, where growth continues at the apices, and flowers are developed in the axils.