Biology XI:6 Anatomy of Flowering Plants(3 The Tissue System)

The Tissue System - Epidermal, Ground, and Vascular On the basis of their structure and location, tissue systems can be divided into epidermal tissue system ground tissue system vascular or conducting tissue system Epidermal Tissue System Forms the outermost covering of plant body The Ground Tissue System Except epidermis and vascular bundles, all tissues are part of ground tissue system. Consists of simple tissues such as parenchyma, schlerenchyma, or collenchyma. In primary stem and roots − ground tissue is represented by parenchyma present in cortex, pericycle, pith, and medullary rays In leaves - ground tissue is represented by mesophyll (thin-walled chloroplast containing cells) The Vascular Tissue System Vascular tissue system consists of vascular bundles. Vascular bundles = Xylem + Phloem There are two types of vascular bundles: Xylem and phloem can be arranged in two different kinds of arrangement within a vascular bundle. Radial arrangement - when xylem and phloem are present in alternate manner on different radii Conjoint arrangement - when xylem and phloem are present in same radii Such arrangement usually has phloem located outer to xylem.