Vascular bundle in a celery stalk (Apium graveolens), coloured scanning electron micrograph (SEM). Celery stalks have numerous vascular bundles which act as a transport system. Shown here is a single vascular bundle in a celery stalk (stick). The vascular bundle contains two types of conductive tissue: phloem (top area) and xylem (lower area). Phloem is tissue that transports larger, organic molecules through the plant. It is composed of several cell types, such as: sclerenchyma, parenchyma, sieve elements and companion cells. The sieve element and companion cell are found closely associated with each other in sieve element-companion cell complex. Xylem is tissue that is responsible for transporting water and nutrients through the plant. Xylem consists of a variety of specialized, water-conducting cells known as tracheary elements (tracheids). Surrounding the vascular bundle are supporting plant collenchyma cells. Magnification: x30 when shortest | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / DENNIS KUNKEL MICROSCOPY |
Bildgröße: | 2613 px × 3483 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |