Water-lily leaf stem. Light micrograph of a cross- section through the leaf stem (petiole) of a white water-lily (Nymphaea alba). This shows the air canals (empty spaces,blue) in the tissue,which make the water-lily buoyant. This type of air- filled tissue is known as aerenchyma,and also improves respiration and photosynthesis. The air spaces are lined by thick wall cells,called sclereids,that have an irregular shape | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Wheeler, Dr. Keith |
Taille de l’image : | 5341 px × 4724 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |