Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 9: Structure of Woody Plants - Coggle Diagram
Chapter 9: Structure of Woody Plants
Concepts
Primary Tissues
epidermis
cortex
vascular bundles
pith
leaves
primary plant body
Secondary Tissues
wood (secondary xylem)
bark (secondary phloem and cork)
secondary plant body
Vascular Cambium
Initiation of the Vascular Cambium
vascular cambium
plural, cambia
produce secondary plant body
cells never undergo cell cycle arrest
cells continue to divid
fascicular cambium
interfascicular cambium
cells come out of cell cycle arrest
resume mitosis
connects with fascicular
Fusiform Initials
long, tapered cells
dicots:
140-462 micrometers
conifers:
700 to 8700 micrometers
periclinal wall
2 elongate cells
1 continues Fusiform Initials
1 differentiates
secondary xylem, or
secondary phloem
anticlinal walls
perpindicular
increase # of cambial cells
Ray Initials
short
more or less coboidal
periclinal cells divisions
1 cell remains cambial ray initial
1 differentiates into
xylem , or
phloem
short cells for storage
Arrangment of Cambial Cells
Ray Initials
: short vertical rows
uniseriate
biseriate
multiseriate
Fusiform Initials
horizontal rows: regular
non storied cambium
horizontal pattern
irregular
Secondary Xylem
Types of Wood Cells
interior cells
vascular cambiums
secondary xylem
wood
tracheids
vessel elements
fibers
sclereids
parenchyma
Fusiform
axial system
simple
treacheary elements ONLY
Ray
radial system
complex
vessels
fibers
axial parenchyma
Growth Rings
1st wood
early wood
spring wood
wide vessels
late wood
thick cuticle
less transpiration
large number of vessels
summer wood
annual ring
both early and late wood
1 years growth
growth ring
alternate arrangement
vessels form throughout season
spring not abundant or wider than summer vessels
Heartwood and Sapwood
Heartwood
center
darker
drier and more fragrant
Sapwood
outer
lighter
moist
Reaction Wood
branches and trunks not vertical
lateral stress
mostly upper side
AKA tension wood
Secondary Phloem
formed from vascular cambium
axial stystem
conduction up and downstream or root
sieve tube members
companion cells
fibers and nonconductor parenchyma
Outer Bark
: Cork and Cork Cambium
production and differentiation of secondary xylem
push out the vascular cambium and secondary phloem
tissues pn periphery either grow or tear
maintain against invasion
fungi
bacteria
insects
formation of cork cambium
inner cells remain
outer cell
differeniates
cork cells
AKA phellem cells
procude cell or 2
few species
mature layers
phelloderm
periderm
cork cambium
layers of cork cells
phelloderm
Secondary Growth in Roots
vascular cambium arises
parenchyma cells mitotically active
star to ground shape
stem and root requirements differ
Anomalous Forms of Growth
Anomalous Secondary Growth
alternate cambia
secondary bodies
differ from common types
Roots of Sweet Potato
increase # of stored parenchyma
vascular cambia arise
xylem and phloem mostly parenchyma
Included Phloem
ordinary secondary xylem and phloem produced
cambium cells stop dividing and differentiate into xylem
cambium no longer exists
secondary phloem reactivated
Unequal activity of the Vascular Cambium
ordinary growth
vascular cambium
equal activity
stem and root round cross-section
conducting capacity increases
flexibility decreases
some species
2 sectors very active
2 sectors inactive
conducting capacity increases
flexibility does not change
Secondary Growth in Monocots
secondary growth not like
gymnosperms
eudicots
basal angiosperms
some treelike and woody
Unusual Primary Growth
Palms Trees
do not taper at tips
do not branch
primary tissue
primary xylem
primary phloem
no vascular cambium
hard and woody
Seedlings
does not have full set of leaves
1st few years
wider and # of leaves increase
no secondary growth
establishment growth
