Lilac stem. Light micrograph of a transverse section through the young woody stem of a lilac (Fraxinus excelsior) tree. The thick epidermis (solid green) is being sloughed (pushed/broken) off by developing underlying cork layers (large radial cells,green),under this is a layer of collenchyma (green). The lower cortex has primary phloem fibres (brownish-black) above a ring of phloem sieve tubes (green). Under the phloem is a ring of cambium (green) above a thick ring of wood (xylem,also green),composed of xylem vessels (large circular holes) and tracheid cells. The medullary rays (radial lines,brownish-green) transport water and minerals to the outside of the stem. The solid pith (centre) is composed of large parenchyma cells (light-green). Magnification: x14 when printed 10 centimetres wide | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wheeler, Dr. Keith |
Bildgröße: | 4724 px × 4832 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |