Curio radicans side windows

Curio radicans leaf windows are sometimes joined by additional, lesser cracks in the wall-like leaf skin parts. This indicates favourable growth conditions when augmentation of received sunlight is allowed to boost photosynthesis.

Windows can also be closed as people choose to do in their houses. When inclement or unfavourable weather, whatever a species might find untoward for its metabolism, calls for reduction in activity, rest is induced, the plant pacing itself.

In this way patient waiting and renewed action alternate in the plant, triggered in the cells by indicators from the environment, such as changes in temperature and moisture (Louis Jordaan, personal communication; Smith, et al, 2017; Vlok and Schutte-Vlok, 2015; iNaturalist; https://thesucculenteclectic.com).