10 of 89

Cell inclusions (ergastic substances)

The non living substances of plant metabolism are termed as ergastic substances. These may be reserve foods, excretory products and secretory products of metabolism.

11 of 89

Types of ergastic substances

Reserve foods
Excretory products
Secretory products

12 of 89

1. Reserve foods

Carbohydrates

Many types of water soluble or water insoluble carbohydrates may be present. Glucose, fructose and sucrose are all water soluble.
Inulin is the only polysaccharide soluble in water which form sphere crystals.
Starch is another polysaccharide which is found in forms like granules.
Cellulose is a complex polysaccharide forming cell wall.
Mucilage which forms gummy solution is another type of polysaccharide.

Proteins

These are nitrogenous substances either soluble or insoluble in water. They may be amorphous (eg aleuronic layer) or crystalline (aleuronic grain) .They are converted to amino acids by proteolytic enzymes.

Lipids

These are reserve food materials of plants. Those which are liquid at room temperature are called oils and solids are termed as fats.

13 of 89

2. Excretory products

Alkaloids

Generally speaking, alkaloids are those compounds that contain N in a heterocyclic ring. These are protective materials of plants discouraging animal or insect attacks. Alkaloids are also detoxifying agents of plants and reservoirs of protein synthesis.

Glycosides

Glycosides are condensation products of sugar and glycol.

Tannins

Tannins are astringent water soluble constituents present in the cell sap.

Resins

Resins water insoluble exudates derived from living sources- largely plants.

Latex

Latex is white suspension wherein microscopically small particles or oil globulesare suspended. Latex is present in lactiferous tissue characteristic to certain families like Euphorbiaceae, Papaveraceae etc

Volatile oil

These are water insoluble fragrant liquids found in the plant. They are also called essential oils. Normally volatile oils are carminative, stimulant and antiseptic.

Mineral crystals

These are water insoluble mineral aggregates which occur in cell wall or cell cavity. Common crystals found are calcium oxalate, calcium carbonate and silica etc

14 of 89

3. Secretory products

These include enzymes, coloring substances/pigments and nectar

15 of 89

Plant tissues

Plant tissue is a collection of similar cells performing an organized function for the plant.

16 of 89

Classification of Plant Tissues

17 of 89

Meristematic tissue

These cells have capacity to multiply. These are small isodiametric cells. These cells are compact, thinwalled, normally cubical and possess prominent nucleus.

18 of 89

Simple permanent tissue

They are not usually changed to any other kind to tissue and normally retain their structural and physiological characters. These cells may be living or dead. These cells vary in shape, size and nature of protoplast.

Epidermis

It is the type of parenchymatous tissue forming the outermost layer of the plant. The outer layer of epidermal cells are often thick and covered with a fatty substance cutin. Its function is to conserve moisture and protect against mechanical injuries.

19 of 89

Parenchyma

Parenchymatous cells are thinwalled polyhedral cells with large central vacuole. Aging results in change in shape, wall thickening and appearance of intercellular spaces.

Collenchyma

It is the supporting tissue found underneath the epidermis of many stems, leaf stalks and midribs. It is similar to parenchyma in structure except that primary cell wall is thickended to give mechanical strength of plant parts.

20 of 89

Sclerenchyma

It is a supporting tissue and is purely mechanical in function. It is found in stems, roots, leaves and other parts along with xylem.

Cork

It is a simple permanent tissue made up of compactly arranged approximately prismatic cells found in radial rows. It forms the bark of stems or roots. Protoplasm in the cork cells dies hence matured cork cells are dead.

22 of 89

Complex permanent tissue

This include xylem, phloem and secretory tissues

Xylem

It is the water conducting tissue of plant. The components of xylem are parenchyma, fibers and tracheary elements.Tracheary elements include tracheids and vessels.

Pholem

It is the food conducting tissue of the plant. The components of phloem are phloem sieve tubes, companion cells, phloem parenchyma and phloem fibers.

Secretory tissues

These are responsible for secretions which may be single celled or multicellular. They may be formed by splitting of cells ie schizogenous or by breakdown of cells ie lysigenous or by combnation of the former and later ie schizolysigenous. The secretions can be tannins, oils (volatile and fixed), mucilage and crystals.
Lactiferous tissue also known as milk tubes are the tissue belonging to some families that produce white juice known as latex.

23 of 89

Xylem

Phloem

24 of 89

Types of vascular bundles

25 of 89

Morphology of Plant parts

26 of 89

Root and Rhizome

Root: that portion of the plant axis which ascends into the soil and is devoid of the leaves
Rhizome: an underground stem which bears both roots and leaves eg Ginger

27 of 89

The rhizomes are the stem structure which can be distinguished from roots by the presence of

Nodes and internodes
Scale leaves
Buds

28 of 89

Morphology of Root and Rhizome

Shape

Cylindrical: circular in outline
Fusiform: thickened at the middle and tapering at the ends.
Conical: broad at the base and tapers towards the apex.
Napiform almost spherical with tapering at the lower part.
Tuberous: that contain tubers
Subcylindrical: nearly cylindrical

30 of 89

Surface characters

Surface – smooth or rough
Presence or absence of scale leaves, nodes or internodes, scars of roots and leaves, transverse ridges, furrows.
Regular or irregular ridges.

31 of 89

Fracture

Short: smooth fractured surface
Fibrous: fine threads extending from broken surface
Splintery: sharp and jagged projections on the fractured surface
Horny: Horn like broken surface
Laminated: Breaking into arranged layer
Granular: Fractured surface exhibiting small rounded prominences

33 of 89

Leaves

Leaves are the lateral outgrowth of plant from stems.

34 of 89

Morphology
Shape:

Acicular: needle shaped
Cordate: Heart shaped
Reniform: Kidney shaped
Lanceolate: lance shaped
Obovate: narrowing base and broading toward the apex
Oblong: long, wide with parallel margins
Ovate: broad at the base and tapering towards apex

36 of 89

Apex

Cuspidate: having sharp end like point of the spear
Acute: ending in a sharp point
Obtuse: rounded or blunt end
Mucronate: terminating abruptly into a short and sharp point.
Enmarginate: having deep notch at the apex

38 of 89

Base

Symmetrical: two sides of midrib being alike
Asymmetrical: two sides of midrib being unlike
Decurrent: leaf blade extends down the petiole
Cordate: heart shaped

40 of 89

Margin

Entire: with continuous margin
Crenate: rounded teeth
Dentate: toothed and teeth directed outwardly
Serrate: having teeth of saw and teeth directed upwardly
Ciliate: with hairs

42 of 89

Surface

Glabrous: smoothed surface or free from hairs and any other outgrowths
Rough: surface is somewhat harsh to tough
Glaucous: shiny green
Pubescent: covered with straight, short hairs
Gland dotted: Having non-sticky glands

43 of 89

Type

Simple: These leaves cant be subdivided to leaflets.
Compound: that has number of leaflets.

# If as single, two, three, four or more leaflets are articulated to the petiole, it is called unifoliate, bifoliate, trifoliate, quadrafoliate, multifoliate etc

45 of 89

Stomata

Stomata refers to a small pore on leaf which are meant for gaseous exchange and transpiration.
Stomata constitute of cell pore, guard cells and subsidiary cells.
# Transpiration is the process of water movement through a plant and its evaporation from aerial parts such as leaves, stem, and flowers.

46 of 89

Types of stomata

Anomocytic type (irregular celled)

Stomata is surrounded by varying no of subsidiary cells Eg Digitalis

Anisocytic type (unequal celled)

Covered by three subsidiary cell and in that one is small in size than other two Eg Datura

Paracytic type (parallel celled)

2 of the subsidiary cells have long axes parallel to the pore Eg Senna

Diacytic type (cross celled)

Guard cells are covered by two subsidiary cells on right angle to that of stomata. Eg Peppermint

48 of 89

Trichome

An elongated tubular outgrowth of an epidermal cell is termed as trichome.

Functions of trichomes

Ion exchange
Protective
Secretion of essential oil
Absorption of water

49 of 89

Types of trichome

Covering trichome

These are the trichomes that have apex and provide physical protection.

Glandular trichome

These are the trichomes that contain glandular head and secrete secondary metabolites.

50 of 89

Covering trichomes can be unicellular, multicellular unbranched and multicellular branched.

51 of 89

Glandular trichomes present in various plants

52 of 89

Bark

All the secondary external tissues lying outside cork cambium is referred as bark.
Bark usually consist of cork (phellem), cork cambium (phellogen) and secondary cortex (phelloderm)

53 of 89

Shape

Curved: concavity on the innerside
Recurved: concavity on the outer side
Channeled: concavity on the inner side is so great to form a deep channel
Quill: one edge overlapping other
Double quill: both edge rolling independently into two separate quills.
Compound quill: quill are packed one inside other.

55 of 89

Characters of outer surface

Smooth or rough
Presence or absence of lenticels
Exfoliates, cracks, fissures, wrinkle, rhytidoma, epiphytes

Characters of inner surface

Striations (fine or coarse longitudinal ridges)
Corrugations (transverse wrinkles)

56 of 89

Flower

It is the specialized shoot which is meant for the sexual reproduction of the plant.
A typical flower consist of calyx, corolla, androecium and gynoecium arranged into four separate whorls.

58 of 89

Pedicel

Pedicilate (long pedicel)
Subsessile (a flower with a very short petiole)
Sessile (a flower with no pedicel)

59 of 89

Type of flower

On the basis of sex organs

Unisexual flower flower having either androecium
Hermaphrodite: flower having both reproductive organs

60 of 89

On the basis of symmetry:

Actinomorhic: A flower which can be divided by any plane into tow equal or similar halves
Zygomorphic: A flower which cannot be divided by any vertical plane into tow equal or similar halves.

61 of 89

On the basis of floral parts arrangement

Hypogynous: The condition in which the sepals, petals and androecium are attached to the floral tube below the ovary.
Epigynous: The condition in which the sepals,petals and androecium are attached to the floral tube above the ovary
Perigynous: the condition in which the sepals, petals and andorecium are attached to the floral tube around the ovary.

62 of 89

Calyx and corolla

No, aestivation, free or fused(poly or gamo), color, shape etc
Eg

Polysepalous: when sepals are free
Gamosepalous: when sepals are fused

Androecium

No, free or fused, extrose or introse

Gynoecium

Superior or inferior ovary, shape size of style and stigma, no of ovules

64 of 89

Fruit

A fruit is regarded as mature or ripened ovary.
A fruit consist of two portions- pericarp (developed from the ovary) and seeds (developed from the ovules).
The pericarp consist of three parts

Epicarp (outer part)
Mesocarp( middle part)
Endocarp (inner part)

66 of 89

Types of fruits

Berry: a fleshy fruit with succulent pericarp and many seeds embedding in the pulp. Eg Tomato
Capsule: Many seeded, one to many chambered dry furit. Eg Stramonium
Cremocarp: Two seeded fruit splitting longitudinally into two mericarps attached by carpophore eg Fennel
Drupe: A fleshy fruit with skiny epicarp, fleshy mesocarp and stony endocarp eg Mango
Hespiridium: A fleshy thick skinned berry with hard and leathery pericarp eg Citrus
Nut: A dry, indehicent, one seeded fruit with hard pericarp. Eg Cashew nut (kaaju)

67 of 89

Shape:

Straight: No curving
Subcylindrical: Nearly cylindrical
Globular: globe shaped
Subshperical: nearly spherical
Ovoid: more or less oval shaped

68 of 89

Adhesion

In superior fruit, the floral part or its remains is attached to the base eg Capsicum
In case of inferior fruit, the floral part is surmounted at its apex

Pericarp and its differentiation

Color, texture, markings (wrinkles, ridges)

Seeds

Number, shape, size, color, hilium, micropyle, testa etc

69 of 89

Seeds

The fertilized ovule is known as seed.
Most of the seeds have two seed coats outer testa and inner tegmen.
The seed is attached to placenta by stalk or funicle.
The raphae is the ridge of fibrovascular tissues formed by the adhesion of funicle and testa.
Hilium is the scar left on the seed where it separates from the funicle.
Micropyle is the minute opening in the seed coat for the absorption of water.

76 of 89

Shape size and color

Seed coats : thickness and texture
Hilium and micropyle: size and position
Perisperm and endosperm: presence or absence along with the nature of reserved food material.
Note: Perisperm is the nutritive material found outside the embroyo sac, is the remains of nucellus. Endosperm is the tissue that surrounds and nourishes the embroyo, developed from primary endosperm nucleus.

77 of 89

Histology of different plant parts

78 of 89

Root

Epiblema

Epidermis of the root, usually single layered

2. Cortex

Consists of parenchymatous cells.
Innermost layer of cortex is called endodermis.

4. Stele

Consists of xylem, phloem, pericycle and pith.

80 of 89

Stem

1. Epidermis

Single layer consisting of compactly arranged parenchymatous cells.

2. Cortex

a. Hypodermis

Collenchymatous, continuous ring or patches

b. General cortex

Parenchymatous , may contain starch grain, mucilage etc.

c. Endodermis

Innermost layer of cortex.

3. Stele

a. Pericycle

Composed of sclerenchymatous fibres, usually absent in monocot.

b. Vascular bundles

In dicot, it is arranged in ring form
In monocot, it is scattered.

c. Medullary rays

Radiating bands of parenchymatous cells which separate vascular bundles

d. Pith

Central part of stele.
May contain starch grains, mucilage, calcium oxalate crysals etc.

82 of 89

Leaf

1. Epidermis

Usually single layered, composed of compactly arranged barrel shaped cells, cuticle stomata trichome present

2. Mesophyll

Differentiated into palisade cells and spongy cells
Pallisade cells are columnar and more or less compactly arranged at right angles to epidermis.
Spongy cells are oval shaped and contains abundant intercellular spaces.

3. Vascular bundles

Xylem is found towards upper epidermis while the band of phloem is found towards lower epidermis.
The bundle sheath is usually composed of parenchymatous cells.

1 of 89

2 of 89

3 of 89

4 of 89

5 of 89

6 of 89

7 of 89

8 of 89

9 of 89