Foxglove root. Light micrograph of a section through the root of a foxglove (Digitalis purpurea) plant,showing secondary thickening. From outer root to centre: layers of cork cells (red); cork cambium (blue); phelloderm and cortex of parenchyma (blue); pericycle (blue ring); ring of outer (primary) and inner (secondary) phloem cells (blue),with sieve tubes and plates (blue); layer of cambium outside the xylem (blue); ring of xylem (red). In the centre of the root there is no pith,but xylem primary metaxylem and protoxylem. The primary cambium has produced secondary xylem,which has filled in-between the xylem arms to form a ring with very large xylem vessels,wood parenchyma and tracheid cells. Magnification: x37 when printed 10 centimetres wide | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wheeler, Dr. Keith |
Bildgröße: | 4395 px × 4394 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |