Light micrograph of a transverse section through a six year old lime tree (Tilia sp.) stem. The image shows the pith (dark,centre),six annual rings of xylem (multicoloured area surrounding pith) & an outer layer (cortex) containing roughly-triangular areas of phloem (green),striped with pink phloem fibres. The xylem is composed of vertical,tube- like cells which conduct the sap upwards from the roots. It contains a radiating system of vascular rays (dark lines),which supply it with nutrients. The phloem is responsible for the distribution of the carbohydrates produced by photosynthesis in the leaves. Magnification: x3 at 35mm size | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Kirby, Richard / David Spears |
Taille de l’image : | 4893 px × 3168 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |