Scape Elongation in Narcissus: The Influence of Floral Organs

SUMMARY To study the effects of floral organs on scape growth of narcissus, the spathe, perianth parts, paracorolla, anthers and gynoecium were excised from the bud in all practicable combinations, and growth regulators were applied to decapitated scapes. Spathe removal induced earlier flowering, and by the third day after treatment had reduced scape growth to 88% of that of intact controls. The removal of other parts (alone or in combination) had no additional effects on scape growth, except for gynoecium removal which reduced growth to 43% of that of intact controls after 3 days. Scape growth continued in all treated plants, however, and by day 23 the decapitated plants had grown 79% as much as the intact controls. The effect of gynoecium removal could largely be replaced by applied auxin; gibberellic acid was partly effective in restoring scape growth.