An Effect of Gibberellic Acid on the Flowering of Xanthium, a Short Day Plant.

Abstract

Xanthium pennsylvanicum plants which had been trimmed to reduce the amount of immature tissues responded to photoinductive treatment with a low order of flowering. Application of gibberellic acid to plants with restricted immature tissues resulted in an increased flowering response. Untrimmed plants and plants which had all immature bud and leaf tissues removed did not respond to gibberellic acid. It is suggested that gibberellic acid may act by promoting an increased capacity for the storage of the flower promoting stimulus in the immature tissues.