Transcript chp 3

Plant Parts
Chapter #3
What are the parts of a plant?
Node: swollen part of stem
where buds form (leaves or
stems grow here)
Cotyledons: leaves formed at
first node (cotyledonary
node)
What are the parts of a plant?
Epicotyl: all of plant formed
above cotyledonary node
Internode: stem tissue
between nodes
What are the types of stems?
1) Woody Stem: trees, shrubs,
woody perennials
2) Grass Stem: hollow or filled
3) Herbaceous Stem: like
woody but softer (clover, alfalfa)
4) Modified Stem:
Types of Modified Stems
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Bulbs: (onion)
Tubers: (potato)
Stolons: above ground runner (strawberry)
Rhizomes: below ground runners (field
bindweed or creeping jenny)
What are the functions of stems?
1) transport water, nutrients,
sugars
2) support leaves
3) store food
What are buds?
• special tissue on stems that can grow into
new plant parts
• buds are described according to:
• 1) structures into which they grow
– -Vegetative: leaves or stems
– -Floral: flowers
– -Mixed: both
• 2) where buds appear on stem
– -Apical: tips of stems
• -if floral = bush
• -if vegetative = vine
– -Axillary: where leaf joins stem
– -Adventitious: near wounds
• 3) How buds are arranged
Bud Arrangements
– Alternate (alfalfa)
– Opposite (beans)
– Whorled (not common)
What is Apical Dominance?
• apical bud tries to make plant grow taller or
longer
• if we remove apical bud, we remove the
apical dominance
What are leaves?
• undergo photosynthesis, exchange gases
What is the difference between a
simple leaf and a compound leaf?
• simple leaf = 2 parts (leaf blade
and petiole)
Leaf
B la d e
P e ti o l e
What is the difference between a
simple leaf and a compound leaf?
• Compound leaf: leaf blade divided into
leaflets
What are the different types of
compound leaves?
• Palmately compound
What are the different types of
compound leaves?
• Pinately compound
What are the different types of
compound leaves?
• Trifoliate (alfalfa)
What is the Hypocotyl?
• part of the plant below the cotyledonary
node
What purpose does the hypocotyl
serve?
1) anchor plant
2) absorb water & nutrients
3) store food
What are the types of root
systems?
-Taproot: one main root, has
no nodes
– (carrot, evergreen, kochia)
-Fibrous root: many nodes,
branching root system
(grasses)
To help prevent soil erosion, which
root system would be best?
• Fibrous
What are the parts of a grass
plant?
• Leaves = Sheath is the part
of leaf that wraps around the
stem
• Joints = internodes
• Culm = stems
Grass Plant Parts
• Tillers = branches, all branch
from the base of the plant
• Crown = union of roots and
stem
• Jointing stage = stems
elongate rapidly