In this article we will discuss about the secondary growth in dicot root. Dicotyledonous roots have limited number of radially arranged vascular bundles. With the initiation of secondary growth some parenchymatous conjunctive tissue cells become meristematic beneath the phloem groups, thus forming strips of meristems equal to the number of phloem groups present. The cells of one-layered pericycle now divide. [...]
In this article we will discuss about the two typical dicotyledonous plants which been selected for the study of internal structure of stem with the help of diagrams. 1. Young Sunflower Stems (Figs. 146 & 147): If a thin and uniform transverse section is taken from a young sunflower stem and observed under the microscope, the following plan in the [...]
Meristematic cells have some distinctive features. They are usually isodiametric and compactly arranged without leaving intercellular spaces. Cells have dense cytoplasm, very small vacuoles and quite prominent nuclei. Plastids are in the pro-plastid stage and ergastic matters are usually absent. Walls are thin, homogeneous and made of cellulose (Fig. 135). These are the characters of truly meristematic cells; departures are [...]