ANGIOSPERMS MORPHOLOGY

In this section we are going to discuss about the root and shoot systems of angiosperms

Introduction

Angiosperm plants are the plants which produce flowers. Like all other category of plants angiosperm plants have there on morphological and anatomical features . We can clearly distinguish whether the plant is gymnosperm or angiosperm.

ROOT SYSTEM

Root system is positively geotropic, Which gross towards the earth. Features of root system is broadly classified into two categories namely

TAPROOT & ADVENTITIOUS ROOT

TAPROOT

Breathing roots

This type of rules are the breathing roots. Help to gaseous exchange. Eg : pneumatophores 

Storage roots 

In tab root system there are mainly 4 types of food storage is occurs namely

*Conical 

*Fusiform

*Napiform

*Tuberous

Conical : Conical food storage structures are like cons there for it is called conifers 

Eg: carrot

fusiform : Fusiform food storage structures are example for radish

Napiform : this type of storage is example for beetroot.

Tuberous : tuberous food storage structures are like tubers

Eg: Mirabilis jalapa

ADVENTATIOUS ROOT

Mechanical support

*Prop root

*Stilt root

*Climbing roots

*Clinging roots

Proproot: prop roots are well known for mechanical support the roots we find in ficus plant is a best example for this 

Stiltroot: Stilt roots are aerial adventitious roots which grow obliquely downwards from basal nodes of the main stem and fix firmly to the soil. 

Eg: Rhizophora

Climbing roots: Climbing roots are the adventitious roots that arise from the nodes or internodes in plants having weak stems. These roots help the plants in climbing 

Eg: pepper 

Clinging root: Clinging root : These are non-absorptive adventitious roots which are found in climbers

Eg: vanda

Nutritional purpose

*Haustoria

*Assimilatory root

*Velamen root

Haustoria: 

 A specialized, modified root of parasitic plants that penetrates into a host plant and functions to acquire necessary nutrients from the host plant they attached

Eg: Loranthus

Assimilatory root : Green colour and perform photosynthesis are called as assimilatory roots

Eg: Tinospora

Velamen root : made up of nonliving compact cells with lignified strips of secondary walls. These cells provide support, prevent water loss, and assist the plant in absorbing water.

Eg : vanda

                stilt root in Rhizophora

                 velaman root in vanda

Food storage

*Tuberous

*Fasciculated

*Monilifor

*Nodulous

*Anulated

Tuberous : This type of root is an enlarged fleshy root modified as a storage organ

Eg: Sweet potato

Fasciculated : The swollen roots or root tubers occur in clusters. In Dahlia they lie at the base of the stem

Eg: Dalia

Moniliform : This kind roots are swollen at regular intervals 

Eg: Indian spinach

Nodulous: Nodules are formed while storing food on adventitious roots

Eg: Turmaric

Anulated:  These thickened roots possess a series of ring-like swellings 

Eg: Psychotria

                         sweet potato

FUNCTIONS OF ROOR SYSTEM

Primary functions : 

* Absorption of water and minerals 

* Conduction of water and food 

* Storage of food

Secondary functions :

* Gaseous exchange

* Climbing

* Moisture absorption

* Photosynthesis

* Flotation

SHOOT

Shoot system is negatively geotropic. Which grows vertically upwards. Supports stem, leaf, fruit,seeds and buds

Stem morphology :

Strong & week stem 

Strong stem 

* Support 

* Maintain weight

Week stem

* Creepers 

* Climber's

* Tendril climbers

* Thorn climbers

* Hook climbers

* Root climbers 

* Linais

LIFE-SPAN

* Epimerals: 

Life cycle company complete within several weeks

Eg: Capsella

* Annuals:

Life cycle complete in a week or a season

Eg: paddy

* Biennials: 

Life cycle complete into seasons of 2 years

Eg: Radish, Carrot

* Perennials :

Life cycle complete several years . Flower bears and fruit produce each year

Eg: mangi tree

* Multiennials: 

Life cycle complete by several years and do not produce flowers every year 

MONOCARPIC PLANT

These are the plants which grows many years and produce flowers onece in the life cycle and die after the production of seeds

Eg: Bamboo

Habit

Herb

Shrub

Tree

Tree are then classifed in to 4 types 

* Caudex

Eg: Coconut tree

* Excurrent

Eg: pine tree

* Deliquescent

Eg: ficus tree

* Culm

Eg: Bamboo

Branching

Monopodial: long rangers are arranged in the bottom parts of the plant and smaller branches are in the top of the plant

Eg: pine tree

Sympodial : distinct Orange mint is a regular branching

Eg: mango tree

MODIFICATIONS

UNDERGROUND STEM MODIFICATION

* Rhizome 

Eg: Ginger

* Stem tuber

Eg: potato

* Cons

Eg: Yam

* Bulbs 

Eg: Onion

                      Ginger rhizome

SUBAREAL STEM MODIFICATION

* Runner

Eg: centella

* Offset

Eg: Eichhornia

* Sucker

Eg: Banana

* Stlons

Eg: Colocasia

AERIAL STEM MODIFICATION

* Tendril

Eg : pea

* Thorn

Eg: bougainvillea

* Phylloclade

Eg: Opuntia

* Cladode

Eg: Asparagus

* Bulbils

* Psuedo Bulbils

                    modified leafs ( thorns )

                      Eichhornia offset

FUNCTIONS

* Support fruit ,flower ,seed

*Transport of minerals , water

* Food storage

* Vegitative propagation

* Transpiration

* Defence mechanism

* Protection

* Photosynthesis

* Mechanical support