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Structure of Woody Plants - Coggle Diagram
Structure of Woody Plants
storied cambium)
Ray initials are typically
grouped together in short vertical rows only one cell wide (uniseriate), two cells
wide (biseriate), or many cells wide
nonstoried cambium
Storied cambia have evolved more
recently than nonstoried cambia and occur in only a few advanced eudicot species,
for example, redbud and persimmon
Vascular Cambium
Initiation of the Vascular Cambium
divided constitute
fascicular cambium
interfascicular cambium
simple meristem
fusiform initials
fusiform initials are 140
to 462 mm
in dicots and 700 to 8,700 mm (almost 1 cm) in conifers
apical meristem cell
fusiform initials have thin primary walls, and plastids
are present as proplastids. After nuclear division, a phragmoplast forms and
elongates toward the ends of the cell.
ray initials
They too undergo periclinal cell divisions
xylem
parenchyma
inner cell
phloem parenchyma
outer cell
produced short cell
gymnosperms
storage parenchyma
albuminous cells.
must extended each year
tips of roots and stems initially
contain only primary tissues
Arrangement of Cambial Cells
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organized in specific patterns
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Ray initials
fusiform initials
Arrangement of Cambial Cells
Secondary Xylem
vascular cambium
wood
secondary phloem
axial system
derived from
fusiform initials,
radial system
ray initial system
Growth Rings
vascular cambium
times of stress
either winter cold
or summer drought
quiescence ceases
the vascular cambium becomes active
and cell division begins.
annual ring
and late wood
the two together
making up 1 year’s growth, an annual ring.
it is easy to see early wood
growth ring
tree may fail to grow and produce a ring
These are occasionally not truly annual rings.
Some people prefer the term growth ring
Heartwood and Sapwood
The dark wood is heartwood .
the
lighter, moister outer region is sapwood
one annual ring is converted to heartwood each year
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Outer bark
Cork and the Cork Cambium
secondary phloem,
the cork
cambium, also called the phellogen
the cork
cambium, also called the phellogen
cells are cuboidal
like ray initials
cork cell
parenchyma
phelloderm
Secondary Growth in Roots
Root vascular cambium contains both ray and fusiform initials, and in many
cases, wood produced in the root is quite similar to that of the shoot, having
sapwood and heartwood and being ring porous
Anomalous Secondary Growth
Roots of Sweet Potatoes
Included Phloem
Unequal Activity of the Vascular Cambium
Secondary Growth in Monocots
secondary vascular bundle
Unusual Primary Growth
