As a part of the A-Z Photographic Glossary of Biological Terms challenge, today it is T for Thermogenesis as illustrated by the Sacred Lotus (Nelumbo nucifera), photographed in the National Aquatic Gardens, Washington DC.
Quite simply put, thermogenesis is as the etymology suggests, the creation of heat, and in the natural world we associate that process with warm-blooded animals like humans and other mammals and with birds that can maintain a stable body temperature by regulating metabolic processes. However, in our example today we find that certain plants like the Sacred Lotus as well as many in the arum family (Araceae) possess this ability too.
In the case of the lotus, the process of thermogenesis and thermoregulation (keeping the temperature stable) takes place in the flowers. Temperatures inside the flowers generally remain between 30-36°C (86-96°F) despite changes in environmental temperatures between about 10-45°C (50-113°F). Thermogenesis begins in the bud, when the petals are tightly closed, continues through a day when the petals open slightly to reveal the stigmas, and ends as the flower opens widely to expose the stamens and this period of thermogenesis and regulation coincides with when the flower is most receptive to pollination.
There is some evidence to show that this strategy might be a reward to insect pollinators that would benefit from a high body temperature while remaining in the flower.