Wood Structure Flashcards
1
Q
What comprises the periderm?
A
- the cork (phellum)
- the cork cambium (phellogen)
- and the phelloderm
- usually appears during 1st year of growth in a layer of cortical cells immediately below epidermis
2
Q
Cork (phellum) structure and function…
A
- dead at maturity
- cork replaces epidermis as protective coating
- inner wall surfaces covered by suberin lamellae
3
Q
What is suberin lamellae and what does it do?
A
- alternating layers of suberin and wax in phellum
- highly impermeable to gases and water
- may also by highly lignified
4
Q
Cork cambium (phellogen) structure and function…
A
- divides to form cells to outside (cork) and cells to inside (phelloderm)
- get “rings” of periderm resulting from periods of cambium activity
5
Q
Phelloderm structure and function…
A
- living at maturity
- resemble cortical parenchyma
- stores nutrients
6
Q
Bark consists of…
A
All tissues outside of the vascular cambium, includes:
- phellum
- phellogen
- phelloderm
- cortex
- primary phloem
- secondary phloem
7
Q
Inner bark…
A
- tissues from innermost cork cambium to the vascular cambium
- living tissue; includes functional secondary phloem
8
Q
Outer bark…
A
- all periderms, cortical, and phloem tissue to the outside of the innermost cork cambium
- dead tissue
9
Q
What are lenticels?
A
Openings in the bark that allows passage of gases to living cells of the bark; appears as lines in the bark
E.g. the small vertical lines on paper birch bark
10
Q
What is dendochronology?
A
The scientific method of dating based on the analysis of tree-ring growth patterns
11
Q
Conifer wood is made up of…
A
tracheids and pits connecting them
-
12
Q
Dicot xylem is made up of…
A
- diversity of cell types
-
