Root : Descending portion of plant axis, develops from radical of embryo; anchors the plants in the soil and serves as organ of uptake of water and inorganic nutrients.
Adventitious root(s) : Roots arising from any part of the plant except its radical e.g., banyan tree, mangroves.

Climbing roots :The plants with weak stem bear climbing roots at their nodes , they enable the plant to climb the support e.g. Lvy , Betel.

Conical :
Tap root which is broad at the base tapering gradually to the apex, e.g. carrot.

Conical root :
The base of the root is board  but gradually tapers towards the apex e.g. carrot.

Epiphytic roots :
An epiphytic plant grows in the crevices of other plants. These fix the plants in the crevices e.g.  Vanela.

Fasciculated roots :
When many tubercular roots occur in a single cluster of fascicle they are called fasciculated roots. This modification is also meant for stronge of food e.g. Asparagus , Ruellia and Dalhia.

Fibrous root :
Repeated branching of the radical; common in monocosts, e.g., onion maize, sugarcane etc.

Fusiform root :
The root is swollen in the  middle and gradually tapers towards the e.g. Radish.

Modified root :
The tap roots are usually modified for stronge of food. Main modified forms of tap root are as follows :

Moniliform roots :
These are also called as beded roots because these arise as swellings at frequent intervals e.g. Fortulaea and Mormordica.

Napiform root :
It is very much swollen at the upper end and suddenly tapers at the other end e.g. Beet root, tumip.

Nodulated root :
The secondary or tertian branches of tap root become nodulated , symbiotic bacteria live inside these nodules e.g. Pea and gram.

Parasitic or Haustorial roots :
The Plant developes sucking roots which penetrate through the stem of host plant and rob the food e.g. cusuta.

Photosynthetic or Assimilatory roots :
They  have green chlorophyll pigments and capable of synthesizing their food e.g. Tinospira , Trapa , and Padostemum.

Primary Root :
Direct prolongation of the radical, common in angiosperms, monocots and dicots.

Prop or Pillar roots :
They are stout , cylindrical , adventitious roots bearing bunch of branches only at the apex. They grow and hang downwards and on reching the soil produce normal adventitious roots e.g. Banyan.

Secondary root(s) :
Lateral branches arising in succession from primary root.

Taproot :
A well established and strong primary root, as in dicots, it may be fusiform, napiform, conical or tuberous.

Tertiary root(s) :
Thinner branches that arise from secondary branches, found only in dicots.

Tuberous root :
The swollen root has no fixed shape and is irregular in outline e.g. Mirabilis jalapa (Four o’clock Plant).

Stem :
The upright part of the plant which grows from pumule of seed is called stem. It bears nodes , leaves and branches.
Axillary bud :The buds which are located in the axil of each leaf are called Axillary or lateral buds. These buds grow into branches.

Buds :
The buds is a small compact structure and the shoot develops from it. Plumule is the first bud.

stem is very much reduced in this case .it is discoid in shape . It bears large number of scale leaves. It possesses terminal bud in the centre and gives rise to aerial shoot that produces flower e.g. onion. It garlic several bublets (small bulbs or cloves) may be seen  within a large bulb. There arise from axillary buds and are capable of developing into new plants.

Bulbil :
A few plants propagate by means of vegetative or floral buds which are called bulbils. They germinate directly to grow into new plants e.g. oxalis , Pineapple, Agave and Dioscorea.

Caudex :
The unbranched , persistent main axis of a plant: it bears a cluster of leaves (crown)  at the apex , e.g., plam trees.

Cladode :
It is a phylloclade with one or two intrerodes only .it resembles a leaf . It arises in the axil of a much reduced scale leaf e.g.  Asparagus and Acuteatus.

Climber :
A weak stem attached to any neighbouring objects and thereby climbing up peas, gourds, vines etc.

Corm :
The corm is a short, vertical underground stem swollen with reserved food. It is unbranched e.g. crocus, Gladilous, Amorphophallus, Colocasia and Alocasia.

Creeper :
Weak stem creeping on the ground and reforming at the nodes. It may be a runner, stolen, offset or sucker, according to its varied nature.

Culm :
Jointed stem with solid nodes, cut hollow internodes, found in clusters in certain monocosts-wheat, bamboo etc.

Erect aerial stem :
Unbranched, cylindrical, erect and stout stem, often marked with scars of fallen leaves.

Forms of Stem

Internode :
The length of the stem between two adjacent nodes is called internode.

Offset :
It is like a runner in all respects with the only exception that it is comparatively thicker and bears a single daughter  plant at its end e.g.  Pistia.

Phylloclade’s or cladodes :
It is branch which take the form and function of leaf. the true leaves are reduced to spines . It is flattened leaf like e.g. opuntia and euphorbia . it is cylindrical in shape in case of casuarinas.

A trailing stem lying horizontal on the ground surface.

It is perennial, fleshy, underground, non-green stem. Nodes are marked as scars bearing dry scale leaves in their axils. Branches and buds are also present. Underground adventitious  roots arise from them e.g. Ginger, Turmeric and banana.

Runner :
They are slender prostrate branches. They have long intemodes which creep on the ground. They bear roots at the nodes. The axillary buds form new branches e.g. oxalis, strawberries, and Doob grass (Cynodon).

Special modifications of steam:
The aerial steams vary in form as they as they are modified to perform special functions they are as follow:

Stem tendril:
It is thread like slender and spirally coiled (spring like) structure which develops from auxiliary bud. It helps the plant in climbing .the tendrils are found in the axil of leaf and hold the support e.g. Passiflora(passion flower) , Antigonon , Grapevine , Cucumber , Pumpkin , Watermelon.

Stolon :
It is a slender branch arising from the base of main axis. It grows the horizontally for some time and then arches to touch the ground. Its terminal bud gives rise to a new shoot and roots, e.g. Mentha , Jasmine.

Sub-aerial modification :
Stems are normally weak, prostrate and touch the ground. They are buried superficially in the soil. Aerial branches and adventitious roots develop at the nodes. They may behave as independent plants when detached. They are generally known as creepers. The modification are of the following types  :

Sucker :
It is like a runner but originates from the basal or underground portion of main stem. It grows horizontally beneath the soil but  soon comes out upward obliquely bearing the leafy shoot. Suckars are shorter and stouter then runner e.g. cotocasia, mint and chrysanthemum.

Terminal bud
: The bud which remains at the tip and continues to grow indefinitely , is called Terminal or apical bud.
The stem, its branches, leaves, flowers and fruits constitute the shoot system of plant.

It is hard sharp pointed needle like structure present in the exil of leaf.  It may bear leaves . they protect plant from browsing animal e.g. Duranta , Citrus , Lyceum etc. .

The tubers are  swollen stems serving for storage of food and  vegetative propagation .The  tubers have axillary buds at the nodes often called as eyes e.g. potato.

Twiner :
A climbing weak stem that winds about its support pale beans.

Underground modification of stem :
some perennial herbs develop their stem underground for the purpose of perenation and storage of food. They helps in vegetative propagation. They appear like roots but are distinguishable from them in having scale leaves at the nodes and buds. The important types of modification are as follows:

Weak serial stem :
stem trailing on the ground without rooting at the nodes e.g. purslane (Portulace oleracea) etc.


Leaf :
A leaf is a lateral flattened structure borne at a node and initiate from the shoot meristem or primordial and gradually enlarges. It usually has a bud in its axil. Leaf contains chlorophyll hence it is the main photosynthetic organ of the plant.

Parts of a leaf :
The basal part of the leaf where it is attached with the stem is called leaf base. On either side of leaf base arise small leaf or scaly structures known as stipules. Depending upon the presence or  absence of stipules, a leaf may be stipules or exstipular. In most of the leaf is swollen and is formed pulvinus. It is responsible for movement.

Leaf stalk or petiole :
In some plants the leaves possess a very prominent stalk called petiole for proper display of lamina. The petiole is generally rounded, groved or may be angular.

Leaf blade or lamina :
The flattened  expanded green  portion of the leaf is called leaf blade of lamina. The  border of the leaf  lamina is called leaf  margin.  The lower portion where petiole combine with lamina is called lamina base. The opposite end is termed apex. In the centre of lamina runs a prominent raised ridge called midrib from which numerous side branches arise called veins. The veins, further divide into finer branches and they form a network. Veins form the skeleton of lamina and act as channels for transport of food, water and minerals.

Leaf apex :
The tip of the lamina is termed as leaf apex. It is of the following types :

Acuminate :
The apex is long and tapering e.g. Ficus.

Acute : Apex is pointed but not stiff, e.g. chinarose.

Cirrhose :
Having non-sensitive tendril like apices e.g. Banana.

Crenate :
Margin is superficially rounded or obviously toothed e.g. Bryophyllum.

Dentate :
Margin is with sharp spreading coarse indentations that are perpendicular to this margin e.g. cucurbita.

Emarginate :
Rounded but with deep notch e.g. Bohinia.

Entire :
When the margin is smooth and not dissected at any point e.g. banyan and mango.

Leaf bladder :
Leaf bladders are small specialized sacs which are found in the aquatic plant Utricularia. The leaves are highly dissected and some become modified to form these bladders. These modifications are to trap animals for obtaining nitrogen.

Leaf modified into roots :
In the case of salvinia, three leaves are present at each node of stem. Out of three, two remain as leaves while the third gets modified to form roots.

Leaf pitchers :
The whole outer lamina of the leaf may be modified to form a large pitcher e.g. Dischidia, Sarsacenia and Nepanthes. These modifications of the pitchers are meant for capturing insects, and collecting water. Each pitcher is provided with lid.

Leaf spines :
The part of leaf becomes changed into spines in order to protect the plant from grazing animal e.g. Opuntia and Acacia.

Leaf tendrils :
Tendrils are thread like structure which are capable of coiling around the support. They may be whole leaf tendrils as in wild pea, leaflet tendrils as in Pisum sativum, petiolar tendril as in Nepantnes, rachis tendrils as in clematis and leaf tip tendril as in Glory lily.

Margins of Leaf lamina :
Following are the various kinds of margins of leaves :

Modification of leaf :
The leaves or their parts may be modified to perform certain special functions other than synthesis of food. The modifications are as follows :

Mucronate :
Apex pointed suddenly from almost rounded region e.g. vinea.

Multicostate reticulate :
When there was more than one midrib arising from a single point e.g. cartor and Ipomoea.

Multicostate venation :
In this case several veins run parallel to one another in a leaf e.g. wheat, corn.

Obtuse :
Apex is rounded e.g. Banyan.

Parallel venation :
When the veins are parallel and do not form a network such a venation is called parallel. It is characteristic feature of monocotyledons. It is of two types :

Phyllodes :
In the case of Australian Acacia the leaf is bipinnate compound. The leaflets gradually fall down and the rachis becomes flattened and green in colour to carry on photosynthesis.

Pinnately lobed :
The margin is with incisions more than the size of tooth.

Reticulate venation :
When the veins are irregularly distributed to form a network, it is known as tericular venation. It is characteristic feature of the dicotyledons. It is of the following types :

Retuse :
Rounded but slightly notched e.g. Pistia.

Serrate :
When the margin is like teeth of a saw e.g. China rose and Rose.

Tendrillar :
Apex long, drawn out and modified into a tendril.

Truncate :
Almost flat e.g. Indian Saga Palm.

Undulate :
When the outline is although smooth, but wavy e.g. Ficus and Ashok tree polyalthia.

Unicostate parallel :
The lamina has a single prominent midrib and from this arise lateral veins which run parallel towards the margin e.g. Banana, Turmeric.

Unicostate reticulate :
A leaf with a single main midrib or casta is called unicostate reticulate e.g. Eugenia (jamun) and Oleander (Kaner).

Venation :
The arrangement and distribution of the veins in the leaf lamina is called venation. It is of the following type :


Flower :
Morphologically it is a shoot bearing nodes and modified floral leaves. Though all flowers have some basic plan, these exhibit wide variation in size, shape, colour and arrangement of floral parts.

Achlamydeous : Naked flowers, flowers that do not have sepals or petals.

Actinomorphic flower :
Flower whose symmetry remains unchanged when it is cut into two halves through any vertical plane passing through the axis.

Aestivation :
Arrangement of sepals in calyx, petals in corolla or tapels in perianth in a floral bud, it is an important diagnostic character and may be of the following types.

Androecium :
Third whorl, composed of stamens or micro-sporophylls, that are regarded as male organs of the flower. Each stamen is made of filament, anther and connective.

Apocarpous (flower) :
Having carpels separate from each other.

Bisexual flower :
A flower containing both androecium and gynoecium.

Bract :
Modified leaf associated with plant reproductive structures, from its axillaries a solitary flower or a cluster of flowers.

Bracteole :
A small bract, especially if on floral axis.

Calyx :
First or the lowermost whorl of green floral leaves called sepals.

Complete flower :
Flower having all the four whorls (sepals, petals, stamens and carpels).

Corolla :
Second accessory whorl of flower, consists of number of brightly coloured petals.

Dichlamydeous flower :
Flower having both calyx and corolla.

Egigynous flower :
Cup shaped thalamus fused with ovary (inferior) so that other floral parts arise on the top of the ovary e.g., apple, cucumber etc.

Flora pleno :
Double flower, in which carpes have also become modified petals.

Floral diagram :
Diagram of a flower in cross-section depicting the number and arrangement of floral parts.

Floret :
Small flower, individual flower of an inflorescene.

Floribunolus :
Flowering profusely.

Floriculture :
Culture of flowering plants.

Floriculus :
A floret.

Florid :
Flowery, ornate.

Floriferous :
Flower bearing, blooming freely.

Floristics :
Study of taxonomic identification and listing of all plant species present in a community.

Florivorous :
Feeding on flowers.

Florula :
Plant (flowers) that grow in small confined habitat e.g. lotus in a pond.

Flower bed :
Strip of well prepared and manured land, usually in a garden or farm, for growing flowers.

Gynoecium (pistil) :
Fourth or female whorl, comprising of carpels or megasporohylls; each pistil is made of three parts – ovary, style and stigma.

Hermaphrodite :
A flower possessing both stamens and carpels.

Hypogynous flower :
The ovary superior is situated on torus, above all the other floral parts e.g. mustard, tomato etc.

Imbrecate :
Overlapping of one or more sepals or petals over adjoining ones e.g. gul mohur etc.

Incomplete flower :
Flower lacking one or more, of the four whorls.

Inflorescence :
A flower cluster; arrangement of flowers on the axis.

Nectar :
Sugar containing fluid secretion of nectarines.

Neuter (sterile) flower :
One that does not have any functional stamen or carpel.

Pedicel :
Stalk of the flower (solitary or part of an inflorescence).

Peduncle :
Main axis of inflorescence on which flowers are borne.

Perigynous flower :
The thalamus forms cup shaped structure around the ovary and bears sepals, petals and stamens e.g. rose etc.

Pistillate :
Having pistil (but no stamen), female unisexual flower.

Pistillode :
A pistil lacking ovule.

Placenta :
Plant surface bearing sporangium (ovules).

Receptacle (thalamus) :
Tip of pedical that continues as an enlarged axis and bears all other floral apprendages (organs). A typical flower consists of four different types of floral leaves – calyx, corolla, androecium and gynoecium.

Staminate :
Male unisexual flower.

Staminode :
A stamen with no functional anther.

Syncarpous :
Gynoecium having carpel united in a compound ovary.

Tapetum :
Layer of nutritive cells surrounding the spore mother cells in sporangium in higher plants.

Tetracyclic flower :
Having all the four whorls.

Thalamus :
Suppressed, swollen end of a floral axis on which the floral leaves are borne.

(controrted) : When one margin of sepals or petals overlaps that of the next one and the other margin is overlapped by third one, twisting may be clockwise or anticlockwise e.g. rose etc.

Unisexual flower :
Flower having either androecium or gynoecium.

Valvate :
When the members of the whorl are in touch with each other by their margins or lie very close to each other but do not overlap e.g. bullock’s eye, madar etc.

Vercillary :
Flower with five petals, of which the posterior one is the largest, almost covering the two lateral petals which in turn nearly overlap the two anterior or the smallest petals – bean, pea etc.

Zygomorphic flower :
Exhibiting bilateral symmetry.

Floral symbols :

B        Bract
C         Corolla
C4        Four fused petals in a corolla
E         Epicalyx
G         Gynoecium
        (Inferior) position of ovary
G        (Superior) position of ovary
K        Calyx
K4       Four sepals in the calyx
P         Perianth
%        Zygomorphic
?         Male
?         Female
?         Bisexual
(   )       Cohesion of a whorl
        Fusion of two whorls

Anemophily :
Wind pollinated, anemophilous flowers are unisexual, with anthers and stigma exposed and pollen grains are small, smooth and dry and are produced in enormous number (a single flower of bhang, Cannibis satira produces over 500000 pollen grains) e.g. coconut palm, date palm, maize etc.

Autogamy (endogamy) :
Self-fertilisation fusion of male and female gametes derived from the same individual flowers (pea, rice, wheat etc.).

Chiropterophily :
Bat pollination – bats are flying (nocturnal) mammals; the flowers they visit, are large with strong scent; the bats move swiftly and transport pollen over long distances (upto 30 km).

Cross-pollination :
Transfer of pollen from anthers of flower on one plant to the stigma of a flower on another plant; it requires assistance of an abiotic – wind (anemophily), water (hydrophily) or biotic agent insects (entomophily), bird (ornithophily), bats (chiropterophily).

Double fertilization :
A unique phenomenon in flowering plants where union of egg and one of the sperm nuclei as also the fusion of second male nucleus with polar nuclei takes place.

Embryo (In plants) :
Partly developed sporophyte which in angiosperms in protected within a seed and if differentiated into a radical, plumule and cotyledons. The product of conception up to the third month of human pregnancy.

Embryo sac :
The female gametophyte of flowering plants, consisting of a sac-like structure inside the ovule in which six haploid cells and two haploid nuclei are found.

Embryoculture :
In vitro growth of isolated plant embryos on suitable culture medium.

Embryogeny (embryony) :
Process of formation of embryo from a fertilized egg cell.

Embryology :
Study of development of the organism from the zygote or fertilized egg.

Embryonate :
Containing an embryo.

Entomophily :
Insect pollination, insects visit flowers to gather nectar and pollen, These insects inadvertently transfer pollen from one flower to another bees are the chief pollinators besides butterflies and moths-clovers, cucurbits, mustard, safflower, sunflower and some pomaceous fruit trees give significantly higher yields if bees are around for pollination. Fig trees (Ficus carica) require certain insect species (Blastophaga) to effect pollination, while orchids (Ephrys spp.) require males of a particular moth who are misguided and consider orchid flower as a female moth and go for (Psuedo) copulation that brings about pollination.

Fertilisation :
Fusion of male and female gametes of the same species to give rise to a zygote which subsequently develops into a new organism.

Geitonogamy :
Marriage between neighbours : self-pollination and fertilization of one flower by another on the same plant.

Hydrophily :
Rare phenomenon that occurs in totally submerged marine plants – ceratophyllum demersum, vallisneria spirals, eel-grass, Zostera marina etc.

Ornithophily :
Bird pollination – birds visit various (osithophilous) flowers to collect nectar and in the process, also transfer pollen from one flower to another.

Pollination :
Transfer and deposition of pollen on the stigmata surface of the flower, it may be self pollination (autogamy, geitonogamy) or cross pollination (allogamy), assisted by abiotic (water, wind) or biotic (insect, birds, bats etc.) agencies.

Self-pollination :
Transfer of pollen from the stamen of a flower to the stigma, either on the same flower (autogamy) or on another flower on the same plant (geitonogamy); it leads to self fertilization, also known as inbreeding.


Fruit :
Fruit is a ripened ovary which is usually formed after fertilization. After the act of fertilization ovary forms fruit and ovules change into seeds. The fruit is also known as Eucarp. Some fruits are formed without fertilization and do no bear seeds. These fruits are described as a parthenocarpic fruits e.g. Banana and Grapes.
Aggregate fruits : They are also produced from a single flower, but gynoecium is bi-, tri- or polycarpellary and apocarpous. The ovary matures to form a simple type of fruit called fruitlet. Thus the whole fruit is  collection of such fruitlets corresponding to the number of carpels in a flower e.g. buttercup, calotropis, etc.

Berries or baccate fruits :
These are simple succulent fruits derived from superior or inferior ovary. Mostly they are many seeded but date is a single seeded berry fruit having membranous endocarp. Endocarp is generally edible in berry fruits.

Classification of fruits :
The fruits are classified according to the nature of pericarp and condition of gynoecium as follows :

Composite fruits :
Fruits formed from an inflorescence are called composite fruits, e.g. Fig, mulberry, etc.

Drupe or Stone fruits :
These are also simple succulent fruits in which the pericarp is differentiated into epicarp, mesocarp and endocarp like berries. They differ from berries in having hard and stony endocarp around the seeds, hence they are also known as stony fruits. The mesocarp is fleshy and edible in mango or fibrous in coconut or dry in Almond. The epicarp is thin and not edible. They are derived from simple or compound, inferior or superior pistil. The drupes of cherry, peach, plum are derived from monocarpellary superior pistil while zizyplus develops from compound and superior ovary. In these drupes, the endocarp is stony, mesocarp is fleshy and edible and epicarp forms outer skin of the fruit. The coconut is a fibrous drupe and develops from compound superior pistil. It has stony endocarp, fibrous mesocarp and membranous epicarp. The air is enclosed in the fibrous mesocarp which makes the fruit fit for floating on water surface. The white endosperm of the seed is the edible portion which contains milk of coconut.

Fleshy or edible fruit :
They usually remain succulent and juicy e.g. drupe, berry, pepo, hesperidium and pome.

Hesperidium :
These are citrus fruits which develop from polycarpellary, syncarpous, superior ovary with axile placentation. Epicarp and mesocarp are fused to form outer skin or rind of the fruit and are easily separable. The endocarp is membranous and surrounds the loculi. The edible portion of the citrus fruit is juicy hairs which are the outgrowth of inner side of membranous endocarp e.g. citrus (orange and lemon etc.)

Pepo  :
It is a special false berry fruit and is derived from tricarpellary syncarpous ovary with parietal placentation. It is many seeded. The seeds are like typical berries and do not separate from the placentae on ripening. The mesocarp, endocarp and placentae are edible. The mesocarp is not separable from rind. The outer thick rind is formed by the fusion of thalamus with epicarp e.g. pumpkin, lagenaria, water melon and cucumis.

Simple fruits :
They are formed on the basis of one fruit from one flower. Thus simple ovary on ripening forms the single fruit e.g. Mango, peech, plum.

True and False fruits :
The true fruits develop from the ovary. In these fruits the ovary wall changes into fruit wall or pericarp which surrounds the seeds. The pericarp is usually differentiated into three layers – epicarp, mesocarp and endocarp and any layer may become edible in fleshy fruits. But in some fruits the other floral parts like thalamus and basal portion of perianth, bracts etc. may also be fused with pericarp to form the main edible portion of a fruit. Such fruits are false fruits or pseudocarp e.g. Apple, pear etc. Apple and pear are false fruits. Almond and orange are true fruits.

Functions of fruits

  1. Protection of seeds in the early stages till they become fully mature.
  2. Dispersal of seeds.
  3. On their decay provide raw material for the benefit of new seedling.
  4. Many fruits are consumed by human beings as food and is source of glucose and pectin.

Seed :
A fertilized ovule consisting of an embryo surrounded by food store for nourishment during germination, with an outer hard coat (testa), it forms a new plant (seeding) on germination.
Cotyledon : First leaf of the embryo of seed plants.

Epocotyl : Embryonic plant stem between plumule and cotyledons.

Funiculus (funicle) :
Short stalk of an ovule by which seed is attached to fruit.

Hilum :
The scar on the seed surface from where funiculus has been detached.

Hypocotyl :
Portion of the embryonal axis between radical and point of attachment of cotyledons.

Micropyle :
A minute pore in the integument at the tip of an ovule, persists in the seed as an opening between hilum and redicle.

Plumule :
Shoot tip, primary bud of a plant embryo.

Radicle :
Embryonic root of a flowering plant.

Seed coat :
The envelope that covers the entire seed except for a tiny pore (Micropyle).

Seed dispersal :
Seeds are dispersed by wind, water or by bursting of explosive fruits.

Testa :
Outer seed coat developed from integument of the ovule, in bean seed. It is thick, smooth and variously coloured, while inner coat is thin, white and often difficult to separate from testa.