Mise en évidence du mouvement des feuilles chez l'épinard (Spinacia oleracea cv. Nobel): rythme endogene

In short day, the angle between the two adjacent leaves of spinach increases during the light period, whereas it decreases in darkness. In primary leaves this movement is only present from 27 1/2 to 47 1/2 weeks. The endogenous nature of the rhythm is confirmed by its persistence under constant conditions (light, temperature and relative humidity)