ROOT SYSTEMS
ROOT ORGANIZATION
Roots systems are usually either:
Tap root (dicots)
or
Fibrous root (monocots)
some plants may have both; e.g. clover
Root Anatomy (Macro)
Root hairs
- major site of water/nutrient absorption
- located in zone of cell maturation
Lateral (secondary roots)
- form near but behind root hair zone
- from cells of pericycle; meristematic
- forms apex; pushes through endodermis,
cortex, epidermis
ROOT FUNCTIONS
Roots:
Anchor
Absorb
Conduct
Store
ROOT FEATURES
Root Cap –
covers root apex
protects and lubricates
secretes mucigel
mucigel also aids water and nutrient
absorption
Root Hairs –
increase absorption
develop in region of maturation
extensions of epidermal cells
Primary Root –
develops from radicle (embryonic root) of
germinating seed . . .
branches into:
Branch (secondary) Roots –
develop from the pericycle of the central
root
Adventitious Roots
Latin adventicius “not belonging to”
arise from stems or leaves
e.g. brace roots of corn
ornamentals often propagated
Taproot –
primary root
persists and maintains dominance
e.g. alfalfa, cotton, pecan
often storage/food source
e.g. carrot, beet, turnip
Contrast Taproot w/ Fibrous Root
Refer to notes
Root Morphology
Four Functional Zones:
- region of maturation
- region of elongation
- meristematic region
- root cap