1. Chapter 4 Lessons 1 and 2
Buds – part of the stem where
growth occurs on a dormant twig

2. Two types of buds:
1. Terminal – at the end of the
branch and allows for growth in
length

3. Two types of buds:
1. Terminal
2. Lateral – on the sides of the
twig and holds the leaf petiole
and developing leaf.

4. Primary growth is growth in length
and comes from the apical meristem
of the roots and shoot at the terminal
bud.
Secondary growth is growth in width.

5. Primary growth is growth in length and comes from the apical meristem of the roots and
shoot/terminal bud.
There are two types of tree branching:
1. Excurrent branching – trees grow tall
and straight from a large central shaft,
have strong terminal buds

6. There are two types of tree branching:
1. Excurrent branching – trees grow tall and straight from a large central shaft, have strong terminal
buds
2.Deliquescent branching – trees grow
outward from several main branches
and have strong lateral buds.

7. Two main sections of a dicot stem:
1. Bark
• Outer section
• protects
• Made of cork cells on outside
• Inner layer is the phloem made of
hollow tubular cells stacked end to
end where food passes through,
where cells meet is the sieve plate

8. Two main sections of a dicot stem:
1. Bark
• Outer section of the stem
• Provides protection
• Made of outer layer called cork
• Inner layer is the phloem made of hollow tubular cells stacked end to end where food passes
through, where they meet is the sieve plant
•In a younger tree instead of the cork
there is the epidermis and the cortex
which is replaced by cork
Sieve plate

9. Two main sections of a dicot stem:
1. Bark
2. Wood
 Inner section
 Provides strength and support
 Transports minerals and water
 Long tubular cells
 makes up the xylem of the wood
 become clogged over time adding
support

11. Two main sections of a dicot stem:
1. Bark
2. Wood
 Inner section
 Provides strength and support
 Transports minerals and water
 Long tubular cells make up the xylem of the wood which can become clogged over time
 Two types of wood:
a. Heartwood – the older inner
wood used only for support, it is darker
in color and is the clogged xylem

12. Two main sections of a dicot stem:
1. Bark
2. Wood
 Two types of wood:
a. Heartwood – the older inner wood used only for support, it is darker in color and is the
clogged xylem
b. Sap wood – is the newer functioning
xylem tissue

13. Two main sections of a dicot stem:
1. Bark
2. Wood
 Two types of wood:
a. Heartwood – the older inner wood used only for support, it is darker in color and is the
clogged xylem
b. Sap wood – is the newer functioning xylem tissue
Note: Younger trees have a third section
to a stem called the pith located in the
center of the stem and is used for water
storage. It disappears as the tree gets
older.

15. Annual Rings:
New wood is formed from the vascular
cambium tissue
Growth in width in secondary growth in
a tree
Growth is seasonal
This seasonal growth leaves a distinct
pattern in the wood called annual rings

16. Annual Rings:
New wood is formed from the vascular cambium tissue
Growth in width in secondary growth in a tree
Growth is seasonal
This seasonal growth leaves a distinct pattern in the wood called annual rings
Spring wood – the ring that is
lighter in color than the Summer/Fall
growth which is darker and smaller

18. Annual Rings:
You can age a tree by its annual rings
The annual rings is what gives wood its
grain which streaks when it is stained