cross section: Younger Trifolium stem common name: Clover magnification: 400x

Like most herbaceous dicots, Trifolium dies at the end of the growing season and consequently capable of limited amounts of secondary growth

Within the stele the vascular bundles are arranged in a ring and separated from each other by medullary rays of parenchyma cells.

The collaterally arranged vascular bundles are almost entirely primary phloem and xylem. Each bundle consists of a large outer supportive cap of sclerenchyma fibers (phloem fiber cap), a deeper layer of primary phloem with well-defined sieve tubes and companion cells, and a deepest layer of primary xylem. In between the xylem and phloem, a narrow band of cambium may be seen. In some preparations, the highly lignified cells walls of xylem and mature sclerenchyma are stained red orange. These cells are dead at maturity and can also be distinguished by a heavy cell wall and absence of cytoplasm.