Transcript Stem Growth - Effingham County Schools

Stems

Possible functions of stems:

Supports leaves, flowers, and fruits

Ex. Tree branches

Conducts water, nutrients and products of
photosynthesis to other parts of the plant.

Ex. Xylem and phloem in the stem
Functions continue…
Can store water Ex: cacti
Can be responsible for asexual
reproduction. Ex. Stem cuttings
What is the meaning of herbaceous?
Having a soft, green stem
The meristem is responsible for continued
growth of the plant.
Stem Growth

Growth in length
Primary Growth
Primary Growth
Growth in
width or
diameter
Stem Secondary Growth

Secondary growth is
responsible for tree ring
formation.
Stem Secondary Growth

What causes
the color
differences in
tree rings?
Tree Rings
Tree rings form due
to growth that takes
place during the year.
Lighter color due to
growth during Spring –
favorable conditions
Darker color due to growth
during the summer –
conditions less favorable
Tree Rings


•
The lighter color in a tree
ring is known as
earlywood.
It is produced early in the
season.
Darker color is known
as latewood or summer
wood.
Produced late in the season
Tree Rings
Early wood
(Lighter ring)
Scar from forest fire
First year growth (pith)
Rainy season
(Rings
(Rings
farfar
apart)
apart)
Late wood
(Darker ring)
Dry season
(Rings
(Rings
close
close
together)
together)
Early wood + Late wood = Tree ring
Primary and Secondary Growth
Tree Cookie Lab