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

AbsorbConduct

Store

ROOT FEATURES

Root Cap –

covers root apexprotects and lubricatessecretes mucigel

mucigel also aids water and nutrient absorption

Root Hairs –increase absorptiondevelop in region of

maturationextensions 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 RootsLatin adventicius “not belonging to”

arise from stems or leavese.g. brace roots of corn

ornamentals often propagated

Taproot –primary rootpersists and maintains dominancee.g. alfalfa, cotton, pecanoften storage/food sourcee.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