Download Plant Morphology Cont. net parallel

Bot 101
Botany: A Human Concern
Plant Morphology
Cont.
•
•
•
Shoot System
winter twigs
leaf morphology
•
•
•
Root System
root architecture
modified roots
The Shoot System
• Leaves
• basic structure (morphology)
midvein
axillary bud
stipule
petiole + blade
=
LEAF
Leaf Morphology cont.
midvein
net
• venation
parallel
palmate
pinnate
parallel venation
net venation
Leaves
• simple vs. compound
rachis
petiole
Simple Leaf
leaflet
(no axillary bud)
Compound Leaf
1
Leaves
• palmately and pinnately compound
twice pinnately compound
palmately compound
Leaf Morphology cont.
• arrangement on stem
alternate
opposite
whorled
Leaf Morphology cont.
• Modifications
Thorns are
modified stems
Spines are
modified leaves
cladophyll
leaf
Prickles are modified
epidermis
2
Flowers
• basic structure (morphology)
• whorls of modified leaves (for reproduction)
• borne on modified stems
• more later
Leaf Morphology cont.
•Modifications
tendril
insect traps
spines
Root Systems
Root Systems cont.
Basic Architecture
(two types)
1.
Tap root system
2.
Fibrous root system
lateral roots
taproot system
• central main root
• penetrate deeply into
soil
• lateral roots branch
from tap
taproot
taproot system
fibrous root system
• many branching roots
• (no central root)
• penetrates upper soil
layers
Taproot
Fibrous
3
Root Structure
• basic structure
lateral root
root hairs
zone of
elongation
root
cap
4