Prunus leaf (Prunus domestica)
Transverse section of leaf of a Plum tree (Prunus domestica), taken through the midrib of the leaf. The leaf blade is less than 1 mm thick.
As with most dicots, the leaves grow at right angles to the direction of light, and the tissues are differentiated to be adapted to the direction of the incident light. Below the upper epidermis is the palisade mesophyll, consisting of more than one layer of vertically orientated cells, containing many chloroplasts.
Below the palisade tissue is the spongy mesophyll, which contains many air spaces. These allow gases to diffuse to and from the mesophyll cells, as well as allowing the movement of water vapour during transpiration.
The midrib contains the main vascular bundle of the leaf. The central pink area of tissue is xylem, containing rows of vessels surrounded by smaller fibres. Vessels transport water and mineral ions to the leaf, and the fibres have lignified cell walls for support. Below the xylem is a darker area of phloem, which transports the products of photosynthesis away from the leaf. Smaller vascular bundles are just visible in other parts of the section.
Cells in the red areas of the leaf contain coloured resins, or pigments such as anthocyanins.
See 'Transverse section of leaf of Hellebore' for more information about the internal structure of a dicot leaf.
Image by John Adds
Prunus leaf (Prunus domestica)
Transverse section of leaf of a Plum tree (Prunus domestica), taken through the midrib of the leaf. The leaf blade is less than 1 mm thick.
As with most dicots, the leaves grow at right angles to the direction of light, and the tissues are differentiated to be adapted to the direction of the incident light. Below the upper epidermis is the palisade mesophyll, consisting of more than one layer of vertically orientated cells, containing many chloroplasts.
Below the palisade tissue is the spongy mesophyll, which contains many air spaces. These allow gases to diffuse to and from the mesophyll cells, as well as allowing the movement of water vapour during transpiration.
The midrib contains the main vascular bundle of the leaf. The central pink area of tissue is xylem, containing rows of vessels surrounded by smaller fibres. Vessels transport water and mineral ions to the leaf, and the fibres have lignified cell walls for support. Below the xylem is a darker area of phloem, which transports the products of photosynthesis away from the leaf. Smaller vascular bundles are just visible in other parts of the section.
Cells in the red areas of the leaf contain coloured resins, or pigments such as anthocyanins.
See 'Transverse section of leaf of Hellebore' for more information about the internal structure of a dicot leaf.
Image by John Adds