Lenticels on the bark of the Himalayan White Birch, Betula Jacquemontii. The picture is a close up view of a strip of bark shed from the trunk of a B. jacquemontii tree. The width of the frame is 4cm. The white background is the outer surface of the paper-like bark; the orange/brown horizontal areas of a granular appearance are the outside surface of the lenticels. On the tree, as here, they are horizontal (ransverse""). Their different sizes reflect their age; they extend as the girth of the tree enlarges. Bark is impermeable to the air; lenticels are porous structures that allow gaseous exchange between the living tissues beneath the bark and the atmosphere outside. Lenticels are found on the stems and roots of woody plants; they also occur on fruits such as apples, and on potatoes.B. jacquemontii is native to the Himalayas, valued in horticulture as an elegant specimen tree" | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Burgess, Dr. Jeremy |
Bildgröße: | 5212 px × 3468 px |
Modell-Rechte: | nicht erforderlich |
Restrictions: | - |