Diurnal leaf movements inOxalis acetosellaandOxalis regnelliishow no sinusoidal shape. The movements are clipped by physiological limits revealing a curve similar to a square wave. Regarding this circumstances the following results have been obtained from long‐term recordings:1.Concerning the recorded shape of the movement it seems unjustified to discriminate only between two states as “day position” and “night‐position” of the leaflets as done until now, since this would neglect the transitions between these positions as the events of real movement. These transitions vary with season.2.The seasonal differences in the circadian pattern of leaf movements, previously described by Mu'ller‐Haeckel are caused by the different steepness of the transitions; the latter depend upon factors of the ZG as LD‐ratio or the magnitude of light‐intensity steps.3.The speeds of spreading movement and folding movement depend to different extents (without interdependence) upon the schedule of a natural artificial LD‐cycle.4.Since the steepness of a transition (i.e. duration or violence of a movement) resembles the magnitude of a driving amplitude, the findings of ZG‐dependence of this amplitude and the mutual independence of spreading and folding speed suggest the existence of two separate systems that attain their driving amplitudes by resonance to the exciting influence of the ZG.5.It can be demonstrated statistically that the phase‐angle differences and the duration of a transition between “day position” and “night‐position” (or vice versa) reveal linear correlations. This resembles fixed phase relations between the ZG and the entrained resonance oscillation that are independent of the seasonal changes of the LD‐schedule.