(4) Anatomy of Roots and Shoots, Secondary Growth

single vascuar cylander in the root

single layers of cells around the stele that can be meristematic, location where lateral roots are formed

ground tissue that includes everything from the epidermis to the pericycle, composed of parenchyma cells

a layer of cells with very thick walls at the innemost layer of cortex

a selective barrier that only allows certain things into the stele

embryonic leaf

• cuticle
• root hair

parenchyma

• cortex-outside
• pith-inside

provides lateral transport/pathway for substances

because of the ranom alignments of the vascular cylinders

middle of the leaf

an opening in the epidermis that lets CO2 in and O2 out

border and open and close the stoma

vascular cylinder in the leaf

evaporation of water from leaf

a product of lateral mersistems

forms secondary xylem and phloem

cells of the vascular cambrium, meristemetic tissue in between the primary xylem and primary phloem

parenchyma cells

forms in the outside layer of the cortex of the shoot, cells divide to produce cork

parenchyma cells are packed with suberin

wax that prevents evaporation of water in shoot and protects from insects

phloem and cork

• wood (xylem)
• bark (phloem)

between xylem and phloem

• pericycle
• periderm
• disintegrate