Stem of Monocotyledonous Plants - Detail

Detail of a closed collateral vascular bundle of corn (*Zea mays*). In monocotyledonous plants such as corn (*Zea mays*), the anatomical structure of the stem in cross-section is relatively simple. The outermost layer of the stem is the epidermis, which serves as the protective "skin." Directly beneath the epidermis, there may be a layer of sclerenchyma tissue that provides structural support. The central region of the stem is filled with fundamental parenchyma tissue, within which scattered collateral vascular bundles are embedded. These vascular bundles are encased in robust sclerenchymatic sheaths. A vascular bundle is a fundamental component of the plant's transport system, consisting of organized conductive tissues arranged in strands. This network of vascular bundles, along with basic tissue, forms a central cylinder in the stem and roots, and in leaves, it appears as veins. The main function of vascular bundles is to transport mineral solutions from the roots throughout the plant (transpiration stream) and to distribute assimilates from production sites to consumption sites (assimilation stream). This transport occurs in specialized vascular tissue, which exists in two main types: xylem and phloem. Both xylem and phloem are found within a vascular bundle, in addition to supporting and protective tissues. ## Keywords plants leaf stem monocotyledonous dicotyledonous differences