PLB 300 Lecture Notes - Lecture 24: Vascular Cambium, Cork Cambium, Rhyniopsida
Document Summary
Xylem and phloem: stele the central cylinder, inside the cortex, of roots and stems around the pith phloem either surrounds the xylem or is interspersed within it. Protostele simplest; solid cylinder of vascular tissue in which the. Siphonostele central pith surrounded by the vascular tissue; the. Eustele vascular cylinder consists of a system of discrete strands. Leaf gaps and leaf traces phloem may form an outside the cylinder of xylem or on both sides of it. Ground: conductive tissues are embedded in the ground tissue, pith a central column of ground tissue. Roots, stems, leaves, vascular tissue are only found in sporophytes of vascular plants. 3 types of gametophytes in vascular plants: nutrition from photosynthesis, nutrition from mycorrhizal fungus endosymbiosis, nutrition stored in spore with endosporic development. Primary growth: growth that occurs relatively close to the tips of roots and stems, initiated by the apical meristem, vertical growth. Secondary growth: thickens the stem and roots, vascular cambium.
