White stonecrop. Berlin, Germany. © Matt Lemon Photography. All Rights Reserved.
White stonecrop (sedum album) is found in the northern temperate regions of the world, often growing in crevices or free-draining rocky soil. As a long-day plant it grows vegetatively for most of the year and flowers in June and July. The white stonecrop is able to acclimate to its environment. It can switch between C3 carbon fixation and crassulacean acid metabolism (CAM) depending on the availability of water. CAM saves water as the stomata on its leaves only open to allow CO2 to diffuse into the leaves at night when the temperature (and therefore evapotranspiration) is lower. Drought stressed plants are also more susceptible to photoinhibition which CAM may help to protect against.
At the time of posting this image, a long dark winter in Germany had only just ended, and photoinhibition, which is caused by an overexposure to light, was hardly a problem for plants or people. Instead, the latter welcomed every ray of sunlight with a serene smile, while the former began to fill the city with colours again. This photo was taken as the sun reached the pots and plants on the terrace outside the kitchen of my family home, which doubled as my study in the mornings.