L9: Secondary Growth Intro Flashcards
Types of secondary (lateral) meristems
vascular cambium
cork cambium
what secondary tissue does vascular cambium produce
secondary xylem and phloem
what secondary tissue does cork cambium (phellogen) produce
periderm
primary tissues
formed by primary growth to increase length in herbaceous plants
cells are supplied by primary meristems
secondary tissue
formed by secondary growth to increase organ width in woody plants
cells are supplied by the secondary meristem
in what direction do initials produce cells in the lateral meristems
to the side in both directions
origin of cork cambium
de-differentiation of parenchyma or collenchyma in the outermost layer of the cortex in the stem
origin of the vascular cambium
from the procambium within each bundle and/or the parenchyma cells between vascular bundles
cork
specialized boundary tissue with air-filled cells that have suberized cell walls and are dead at maturity
phelloderm
living parenchyma
suberin
a waxy material located within the cell walls of cork cells that forms a protective barrier that is impermeable to water
lenticels
interruptions/intrusions in the cork layers that allow for gas exchange and transpiration to occur
vascular cambium
makes all secondary vascular tissues
generates secondary xylem to inside and phloem to the outside
how thick is the vascular cambium
1-3 cells thick
2 types of initials in the vascular cambium
fusiform initials and ray initials