Effect of Environmental Conditions of Cultivation Site on Morphology of Flower Spikes in Schizonepeta tenuifolia Briquet

Abstract

The current work aims to clarify the effects of environmental conditions on the flower spikes morphology of Schizonepeta tenuifolia Briquet. Two types of S. tenuifolia (NK and TH) were grown at six sites in Japan. The percentage of florets in flower spikes (floret ratio) of NK was observed to correlate with August and September temperatures, with a lower floret ratio at higher temperatures. The flower spikes of TH had branches, and the number of branches tended to increase with the higher temperatures of August and September. Additionally, the floret ratio of TH was correlated with the number of branches in flower spikes, with a lower floret ratio as the number of branches increased. These results suggest that cooler conditions around flowering improve the quality of flower spikes.