Photosynthetic utilization of internal carbon dioxide by hollow-stemmed plants.

The hollow stems of wet-meadow and bog plants often contain relatively large amounts of carbon dioxide. The internal carbon dioxide apparently originates from respiration of root and stem cells. Some of this carbon dioxide is fixed photosynthetically by stem tissues and is thus recycled within the plant. Such internal stem photosynthesis would be advantageous, particularly in the early stages of growth in cold, wet, high-altitude environments.