Light micrograph of a transverse section through a two year old lime tree (Tilia sp.) stem,showing the second year xylem (bottom left),cambium layer (narrow,green,curved band) and phloem (upper right,striped with pink phloem fibres). The xylem is composed of vertical,tube-like cells which conduct the sap upwards from the tree roots. It contains horizontal vascular rays (green lines),which supply it with nutrients. The phloem is responsible for the distribution of the carbohydrates produced by photosynthesis in the leaves. The cambium is a region of active growth where both xylem and phloem cells originate. Magnification: x50 at 35mm size | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Moulds, Sidney |
Bildgröße: | 3870 px × 2480 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |