Common daisy root. Light micrograph of a section through the root of a common daisy (Bellis perennis) plant,showing secondary thickening. From outside inwards: layers of cork cells (red); cork cambium (green); phelloderm and cortex of parenchyma (green); pericycle (green ring); ring of outer (primary) and inner (secondary) phloem cells (dark green,small) with sieve tubes and plates (light green); thick layer of cambium cells outside of the xylem (light green); ring of xylem (red). At centre there is no pith but the xylem,primary metaxylem and protoxylem make up of four star-shaped arms of the four medullary rays (green). The primary cambium has produced secondary xylem,in-between the xylem arms to form a ring with very large xylem vessels,wood | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wheeler, Dr. Keith |
Bildgröße: | 4394 px × 4394 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |