MORPHOLOGY OF FLOWERING PLANTS -RAVAL ZEBA

1.PARTS OF A TYPICAL FLOWERING PLANT:

Root System Shoot System •Homogenous•Consist of Roots and its Branches

•Homogenous•Consist of Stem, branches , leaves, flowers

PARTS OF PLANT BODY

Vegetative Parts Reproductive Parts•Promote Nutrition and Growth•Root, Stem , Leaves

•Responsible for Reproduction•Flowers

SOME INFORMATION : Study of external Structure of Plants::”External Morphology”Study of internal Structure of Plants:”Internal Morphology”

ABOUT ROOTS:Positively Geotropic: grows downwards Negatively Phototropic: away from lightPostively Hydrotropic :towards waterDon’t have Nodes Internodes

FUNCTIONS: •Fixation• Anchorage (hold to soil)•Nutrition( pass nutrients)•Gas Exchanger( soil to plant)•Food storer ( become swollen)•Food manufacturer•Aerial roots absorb moisture from air

2. PARTS OF A ROOT AND THEIR FUNCTIONS

REGIONS MADE FROM

SITUATED IN:

FEATURES FUNCTION

1.REGION OF ROOT-CAP

Provide protection to Root

Above Root

Appears like multicellular cap-like

Secrete mucilage for lubrication

2. CELL DIVISION/MERISTEMATIC REGION

Compact arranged meristematic cells

After Root-cap

Is growing part of plant

Enable longitudinal growth of new cells

3.REGION OF ELONGATION

Newly formed cells

Above Meristematic Region

Cells here elongate rapidly

Help in Abosorption of mineral salts

4.REGION OF ROOT HAIR/ ABSORPTION:

Root hairs(tiny outgrowths)

Over Roots Single-celled, tubular , remain contact with soil

Absorption of water

5.MATURATION/ CELL-DIFFERENTIATION REGION:

Primary root tissues(Cortex, Xylem ,phloem , etc)

Forms major part of root

Lateral roots also develop from here

Fixation (hoilding) and absorption

2.(A) TYPES OF ROOTS

Tap Roots Fibrous Roots

•Develops from radicle•Grow Vertically downwards into :•Primary root• Secondary Roots•Tertiary Roots

•Roots are in ”Acropetal Succession” Old at base, young at top•Present in Dicot plants

Grow horizontally

•Develops from any other part then Radicle•They have equal sized growth of roots•Also called” Fibrous root system”•Present in Monocot plants

2 (B) MODIFICATIONS OF ROOTS:1.MODIFICATIONS OF TAP-ROOTS:

FOR RESPIRATION:

1. Plants growing in marshy, swampy, salt lakes are called “Halophytes”

2. PROBLEM: Inability to respire in soil, as soil is water-logged

3. SOLUTION: Turn “Negatively Geotropic” and grow vertically upwards

4. Have special cells “lenticels” who respire

2. MODIFICATIONS OF ADVENTITIOUS ROOTS:1. FOOD

STORAGE :

1. Don’t have definite shape

2. Arise from stem and dig into soil

1. Cluster of roots become fleshy (to store food)

2. Found at base of stem

SIMPLE TUBEROUS ROOTS, e.g Sweet potato

FASCICULATED TUBEROUS ROOTS ,e.g dahlia

2.FOR MECHANICAL SUPPORT 1.PROP ROOTS :

1. These Roots arise from branches

2. Grow downwards3. FUNCTION: Provide

mechanical support to heavy branches

2.STILT ROOTS:1. Stems of such plants are weak2. For that, Roots arise from stem

and grown downwards to soil to give support

3.CLIMBER ROOTS:•Plants like such produce roots from nodes•These roots attach themselves to any support and continue growing.

BANYAN TREE

PANDANUS

3.FOR SPECIALIZED FUNCTIONS :1.EPIPHYTIC ROOTS:

1. Orchids like plants grow on branches to reach for sunlight2. They have green leaves( so can photosynthesize), these

plants called ”epiphytes”

3. They have “Velamen” tissue inside which helps in absorption of moisture form air

CUSCUTA

HOST

PARASTITE HOST

2. SUCKING ROOTS /HAUSTORIUM :1. Parasite plants attach to Host plants for feeding on their

body.2. In partial Parasitism, Plants penetrate Xylem only :Take

water and minerals3. In Whole Parasitism, penetrate Xylem: take water and

minerals + Phloem :take food away

5.1.2 MORPHOLOGY AND FUNCTIONS OF STEM:

1. Describe in Shoot system “Aerial part of plant”2. Can be defined as , Ascending part :moves upwards

develops from plumule divided In nodes and Internodes (refer diagram )

3.Is, Positively Phototropic: Moves towards light

Negatively Geotropic and Hydrotropic: moves away from soil and water

BUDS : Young shoot containing young leavesThere are two types of Buds

Vegetative Buds: Buds which develop in branches

Floral buds : buds developing in flowers

ACCESSORY BUDS (extra buds)

ADVENTITIOUS BUDS

FUNCTIONS OF STEM:1. Give Support to plant body2. Conduct Water, Minerals 3. Food TransporterCan also, store food, 4. proliferation and propogation,5. Produce support for climbing6. Offer protection ( spines)

MODIFICATION OF STEMS :I) UNDERGROUND MODIFICATIONS :

TUBER

RHIZOME

BULB

CORM

II) SUB- AERIAL MODIFICATIONS :

III) AERIAL MODIFICATION OF STEM:STEM TENDRIL

THORN

PHYLLOCADE

cladode

BULBILS

5.1.3 MORPHOLOGY AND FUNCTIONS AND PARTS OF LEAF:

PARTS OF A FOLIAGE :

PETIOLE/MESOPODIUM

LAMINA/EPIPODIUM

LEAF BASE /HYPOPODIUM

VENATION :

TYPES OF VENATION :

PINNATELY COMPOUND LEAVES:

MODIFICATIONS OF LEAVES:

LEAF SPINES LEAF TENDRILS

LEAF HOOKS PHYLLODES

PHYLLOTAXY

FLOWERS

RACEMOSE

CYMOSE

PARTS OF A FLOWER

FRUITS

PARTHENOCARPIC FRUITS

SIMPLE FRUITS

AGGREGATE FRUITS

COMPOSITE FRUITS