FBS 10 LAB 2

plant roots

“the part of a plant which attaches it to the ground or

to a support, typically underground, conveying water

and nourishment to the rest of the plant via numerous

branches and fibers.”

Anchor plants
Food reserves
Absorb water and dissolved minerals
Transport materials

Root system (characteristics)

Root cap
region of cell division
region of cell elongation
region of cell maturation
Root hair

External structure of roots

Region of maturation 

cells begin to
differentiate into special cell types; root hairs
are found in this region

Region of elongation

newly formed cells increase in length

Region of cell division

location of actively dividing cells.

Root cap

protects the root tip

absence of nodes
uncutinized
protective covering in the tip
arrangement of primary tissues on early stages

Can be distinguished from the stem

by the following:

Primary Root
Adventitious Roots

Root Classification: Based on Origin

Primary Root

directly emanating from the

embryonic root (radicle) (secondary and

tertiary roots arise from the primary root, and

so on)

Adventitious Roots

arising

not from the radicle, but from

any other plant parts

Fibrous Root System
Taproot System

Root Classification: Based on form and structure

Fibrous Root System

Taproot System

Fibrous Root System

Does not penetrate deeply into the soil

Prevents soil erosion

Common among monocot species

Taproot System

Penetrates deeply into the soil

Functions as a storage organ

Good at anchoring the plant in place

Root Hairs

extension of the roots that

absorb a considerable amount

of water by forming an intimate

association with soil particles.

Trichoblast cells

the

particular cells that produce root

hairs.

Underground culms (Rhizomes)

Bamboo Root System

Clumping 

Running

pachymorph rhizomes
form clumps(non invasive)
sympodial type 

Clumping Bamboo(root characteristics) 

Sympodial type

Rhizomes always turn upward and become culms

Clumping Bamboo

leptomorph (Horizontal rhizome)
monopodial type (running)

Running Bamboo

Monopodial type

Any new rhizome will

grow horizontally underground and

produce more new culms and rhizomes

and this behaviour gave this type of growth

‘running.’

Running bamboo

Running bamboo

Clumping bamboo

Running bamboo

adventitious emerging from a region of the trunk

Palm Root System

Modifications

defined

as morphological changes

in an organ to perform

certain special functions

other than or in addition to

the normal functions.

Storage 
Mechanical support
Vital functions 
others

Types of root modifications

Fleshy Tap Roots

intended for

storage of (starch) and come in several

forms and shapes. Most fleshy types

are considered edible hence, the term

“root crops”.

Tuberous Root

Fasciculated fleshy root

nodulose

moniliform

Annulated

Tuberous Root

do not assume a definite shape and occur singly, e.g., Sweet Potato

Fasciculated Fleshy Roots

clusters and they lie at the base of the stem

Moniliform

swollen at regular intervals

like beads of a necklace e.g., Basella (Portulaca)

rubra, Momordica

Nodulose

the swellings occur only near the tips

e.g., Curcuma amada (Mango ginger), Maranta sp.

Tuberous Root

Fasciculated Fleshy Roots

Moniliform

Nodulose

Annulated

Tuberous Root
Fasciculated
Moniliform
Nodulose
Annulated

Modification: Storage

Prop roots
Stilt roots
Clinging
Buttress

Modification: Mechanical Support

Prop roots

Stilt roots

Clinging

Buttress

Assimilatory Roots
Epiphytic Roots
Floating Roots
Contractile
Reproductive Roots
Haustoria or Parasitic Roots
Pneumatophores

Modification: Vital Functions

Assimilatory Roots

Epiphytic Roots

Floating Roots

Contractile

Reproductive Roots

Haustoria

Parasitic Roots

Pneumatophores

Mycorrhiza

Root Nodules (Rhizobium)