Transverse section of part of a hollow stem of a buttercup (Ranunculus sp.)
In this young hollow stem of a buttercup (Ranunculus sp.), a dicot, the conducting tissue is contained within separate vascular bundles, forming a peripheral ring around the stem.
Most of the tissue of the stem consists of thin-walled packing cells called parenchyma. Between the vascular bundles and the outer epidermis is a region known as the cortex. Here the parenchyma cells are relatively small and contain chloroplasts for photosynthesis. Inside the ring formed by the vascular bundles, the parenchyma consists of larger cells. This region is called the pith. In many plants, like this specimen, the pith is hollow
Cells of the parenchyma support the stem by their turgidity. In older stems the support role is achieved by growth of new tissues, in a process called secondary thickening.
The diameter of the largest xylem vessel is about 30 µm.
Image by John Adds
Transverse section of part of a hollow stem of a buttercup (Ranunculus sp.)
In this young hollow stem of a buttercup (Ranunculus sp.), a dicot, the conducting tissue is contained within separate vascular bundles, forming a peripheral ring around the stem.
Most of the tissue of the stem consists of thin-walled packing cells called parenchyma. Between the vascular bundles and the outer epidermis is a region known as the cortex. Here the parenchyma cells are relatively small and contain chloroplasts for photosynthesis. Inside the ring formed by the vascular bundles, the parenchyma consists of larger cells. This region is called the pith. In many plants, like this specimen, the pith is hollow
Cells of the parenchyma support the stem by their turgidity. In older stems the support role is achieved by growth of new tissues, in a process called secondary thickening.
The diameter of the largest xylem vessel is about 30 µm.
Image by John Adds