Home » Class XI » XI Biology » Plant Families

1- CAESAL PINIOIDEAE/CASIA FAMILY

CLASSIFICATION

  • DIVISION : ANGIOSPERMS
  • CLASS : DICOTYLEDON
  • SUBCLASS : POLYPETALAE
  • SERIES : CALCIFLORAE
  • ORDER : ROSALES
  • FAMILY : LEGUMINOSAE
  • SUB-FAMILY : CAESALPINIOIDEAE OR CAESALPINIACEAE.

GENERAL CHARACTERS

Majority of these plants are trees or shrubs, about 135 genera and 5800 species are known .

VEGETATIVE CHARACTERS

ROOT
Usually, Taproot with nodules and primary, secondary and tertiary divisions.

STEM
Usually, Climbing stem or erect herbaceous or woody, Some plants show xerophytic character.

LEAVES
Usually, Compound leaves bipinnate, stipulate.

INFLORESCENCE

Usually, Racemose.

FLORAL CHARACTER

Usually, Complete, bisexual, perigynous, zygomorphic, pentamerous.

CALYX
5 sepals, polysepalous, imbricate or valvate, Green in colour.

COROLLA
5 petals, poly petalous, imbricate aestivation.

ANDROECIUM
Usually, 10 stamens, polyanderous, exerted, extrose.

GYNOECIUM
Usually Monocarpillary, perigynous, placentational marginal, unilocular with many ovules.

FLORAL FORMULA
+ , Q , K(5) , C(5) , A10 , G1/

POLLINATION
Usually, Cross pollination by insects (entomophilly)

SEEDS
Usually, Both endospermic and non-endospermic.

FRUIT
Legume pod.

ECONOMICAL IMPORTANCE

MEDICINAL PLANS

  • Amaltas
  • Kachnar
  • Tamarindus Indica
  • Panwar. e.t.c.

ORNAMENTALS

  • Parkinsonia
  • Gul-e-mohar
  • Cacia sophera

DYES AND STAINING
Haemotoxylin is obtained from haemotoxylon campechianom.

EDIBLE FRUIT
Lomentum (Imli)

FIBER
Suitable fiber for paper making is obtained from parkinsonia Aculeata.

FAMILIAR PLANTS

Botanical name…………Common Name……………Local Names
1-Tamarindus indica………Tamarind……………..Imli
2-Cassia fistula…………Amaltus.
3-Bauninia verigata………Camel’s foot………….Kachnar
4-Poinciana regia………..Flame of Forest ………Gul-e-Mohar
5-Parkinosia roxburgai……VilayatiKikar

FLORAL DIAGRAM

(From Book)

2 MIMOSACEAE

ALTERNATE NAME

It is also known as “Acacia family”.

CLASSIFICATION

  • DIVISION : ANGIOSPERMS
  • CLASS : DICOTYLEDON
  • SUBCLASS: POLYPETALAE
  • SERIES : CALCIFLORAE
  • ORDER : ROSALES
  • FAMILY : LEGUMINOSAE
  • SUBFAMILY : MIMOSACEAE / ACACIA

GENERAL CHARACTERS

It is the smallest group among the 3 groups of family legume. It contains about 40 genera and 1450 species.

HABITAT

Mostly plants are distributed in tropical and subtropical regions. Great variation inhabit, usually these trees are perinial or binnial shrubs, some are herbs and climbing.

VEGETATIVE CHARACTERS

1. ROOT
Usually, Tap root with side branches, nodules are present.

2. STEM
Usually, Erect and woody stem, rarely herbacious, tannin and gums may also present.

3. LEAVES
Usually, Compound, bipinnate, stipule are modified into spines. In many plants leaves show sleeping movement or after having a shock.

INFLORESCENCE

Mostly, racemose.

FLORAL CHARACTERS

Usually, Complete, bisexual actinomorphic, perigynous, pentamerous.

1. CALYX
Usually, 5 sepals, gamosepalous, valvate.

2. COROLLA
Usually, 5 petals, polypetalous, valvate aestivation, small size.

3. ANDROCEIUM
Usually, numerous stamens, exerted, extrose, basifixed anther.

4. GYNOECIUM
Usually, Monocarpillary, perigynous, unilocular, placentation marginal, many ovules in locule.

POLLINATION
Usually, cross pollination by insects (entomophilly).

SEEDS
Usually, Non-endospermic or with very little endosperm.

FRUIT
Usually, It is called legume.

FLORAL FORMULA

+ ,Q , K(5) , C(5) , Aα , G1/

ECONOMICAL IMPORTANCE

1.WOOD YIELDING PLANTS
e.g-prosopis

  • Acacia species
  • Albizzia
  • Xyliaet

2. ORNAMENTALS
e.g-Mimosa pudica (chuimoi)

  • Austratian Acacia
  • Neptunia

3. FOODER
From leaves of prosopis,

  • Acacia
  • Dicrostachys e.t.c.

4. SOAP POPS
Acacia concinna pods have (soponim), a substance can be used as Soap.

5. CATECHU (KATHA)
Piece of hard wood

6. MEDICINAL USE

  • Katha
  • Siah Kanta
  • Entada
  • Acacia senegal

7. GUMS & DYES

  • Katha
  • Safed Babul
  • Sada Babul

IMPORTANT FAMILY MEMBERS

BOTANICAL NAME…………..COMMON NAME…………….LOCAL NAME
1-Acacia nilotica…………….Gum tree……………..Bauble, Kikar
2-Albizzia lebbek…………….Siris
3-Mimosa pudica……………..Touch-me-not…………..Chhui mui
4-Prosopis glandulosa…………Prosopis……………..Devi
5-Acacia catechu……………..Katha plant

FLORAL DIAGRAM

(FROM BOOK)

3- ROSACEAE

CLASSIFICATION

  • Division
  • Class
  • Subclass
  • Series
  • Order
  • Family: Rosaceae / Rose family.

GENERAL CHARACTERS

It has about 100 genera and 2000 species.

HABITAT

These plants are found growing all over the world 213 species of about 29 genera are reported from Pakistan.

VEGETATIVE CHARACTERS

1. ROOT
Usually, Tap root with its usual branching.

2. STEM
Usually, Green herbaceous, cylindrical, small spines are also present.

3. LEAVES
Usually, Simple leaves with or without petiole, Opposite or alternate.

INFLORSCENCE

Usually Racemose

FLORAL CHARACTERS

Usually, Complete, bisexual, actinomorphic, perigynous, pentamerous.

1. CALYX
Usually, Sometime epicalyx may also be present, of variable number, 5 sepals are present, Gamosepalous, green, pubescent.

2. COROLLA
Usually, 5 petals or multiple of 5 petals, polypetalous, aestivation, imbricate, shape-rosaceous, full of colour.

3. ANDROCEIUM
Usually, Nomerous stamen,ditheous, anther, enerted, extrose, dorsi fixed.

4. GYNOECIUM
Usually, Monocarpillary or multiple capillary with formation of a single compound pistil. Ovary perigynous, unilocular two or more ovules are present, placentation axile when the carpels are many and syncarpous

FLORAL FORMULA

+ , Q , K(5) , C(α) , Ax , G1/ (2-5) or x

ECONOMICAL IMPORTANCE

FRUIT
Economical importance of this family is great in providing the pleasure and welfare of mankind. Plants of many famous fruits belong to this family for e.g. Apple, pear, peach, e.t.c. Perhaps they rank 3rd in commercial importance in the temperate, zone among the families of flowering plants.

ORNAMENTALS
A large no. of ornamental plants of this family are grown in parks and gardens the most widely cultivated plant for this purpose is Rosa. Many others genera are also grown for their beautiful flowers in homes and gardens.

OTHERS
Branches of crataegus and cotoneaster provide excellent walking stick and wood. The wood of pyruspastia is used for making tobacco pipes. In Asian countries rose petals are used in making Gul Khand and are also used in extraction of an essential oil, Rose oil, used as perfume or may be used as eye cleaner in certain diseases.

FAMILIAR PLANTS

BOTANICAL NAME……………….COMMON NAME…………..LOCAL NAME
Malva silvestis……………………….Apple………………..Seb
Pyrus pyrifolia……………………….Pear…………………Nashpati
Prunus amygdalus………………………Almond………………..Badam
Rosa indica…………………………..Rose………………….Gulab
Prunus persica………………………..Peach…………………Aru

FLORAL DIAGRAM

(FROM BOOK)

4-SOLANACEAE

ALTERNATE NAME

Night shade or Potato family

HABIT AND HABITAT

  • It is widely distributed in temperate region and very abundant in tropical countries.
  • The plants are usually herbs or climbing vines but may be shrub.

VEGETATIVE CHARACTERS

1-ROOT
Tap root and branched

2-STEM
Herbacious, erect or underground(Potato)

3-LEAF
Alternate in vegetative and opposite in floral region

FLORAL CHARACTERS

INFLORESCENCE
Cyme sometimes helicoids

1-FLOWER
Pentamerous, Bisexual, Regular, Actinomorphic, Hypogynous.

2-CALYX
Five, united sepals

3-COROLLA
Five petals, united, valvate aestivation

4-ANDROCIEUM
Five stamens, Inserted on Corolla

5-GYNOECIUM
Bicarpellary, Syncarpous (Carpels fused), Placentaion axile.

6-FRUIT
Capsule Berry or Xanthium.

7-SEED
Minute with abundant endosperm.

FLORAL FORMULA

+ , O , K(5) , A5, C(5) ,

ECONOMIC IMPORTANCE

Members of this family provide drugs and food. Some plants are poisonous and other are ornamental. This family is of great economic importance as it provides food, fodder, drugs and ornamentals.

1-FOODER

  • Solanum tuberosum (Potato)
  • Lycopersicum esculentum (Tomato)
  • Solanum melongena (Brinjal)

2-CONDIMENTS

  • Fruit of capsicum
  • Capsicum frutenscens

3-EDIBLE FRUIT

  • Physalis (Cherry or Rasbhari)

4-DRUG YIELDING

  • Atropa belladonna (atropine)
  • Dotura (Daturine)
  • Used in severe cold and in eye diseases.
  • Sap of hanbane is used in dilating the pupils, white cherry is used an nerve tonic.

5-ORNAMENTAL

  • Cultivated in gardens
  • Petunaia
  • Nicotiana
  • Cestrum Schizanthus
  • Brunfelsia solanum

6-CIGARETTE MAKING

  • Nicotiania tobacum (Tobacco)

IMPORTANT FAMILY MEMBERS

BOT-NAME……………………COMMON NAME…………………….LOC-NAME
1-Solanum Tuberosum………………Potato…………………………Aaloo
2-Solanum Melongena………………Bringal………………………..Bengan
3-Lycoperscum Escalentum………….Tomato…………………………Temater
4-Capsicum Annum…………………Red-Pepper……………………..Lal-mirch
5-Petunia Alba…………………..Petunia
6-Solanum Nigrum…………………Black Night shade
7-Datura Alba……………………Thorn apple
8-Nicotiana Tobaccum……………..Tobacco………………………..Tambako
9-Atropa Belladonna………………Deadly night shade
10-Cestrum nocturnum……………..Lady of night…………………..Raat ki Rani

FLORAL DIAGRAM

FROM TEXT BOOK (BIO-XI FAMILY SOLANACEAE )

5-FABACEAE

ALTERNATE NAME

Papilionaceae or Pea family

HABIT AND HABITAT

Plants are herbs, shrubs or trees. Climbers, aquatic plants or xerophytes. World wide distributed.

VEGETATIVE CHARACTERS

1-ROOTS
Tap root, branched bearing tubercle containing nitrogen fixing bacteria.

2- STEM
Herbecious or woodi, erect or climber.

3-LEAF
Simple or commonly compound alternate, stipulate

FLORAL CHARACTERS

1- INFLORESCENCE
Racemose, rarely solitary.

2- FLOWER
Bisexual, irregular, zygomorphic, hypogynous.

3- CALYX
Five sepals, united

4- COROLLA

  • Five petals, usually free.
  • Corolla is papilionaceous (Butterfly shaped). In this form the petals are 5, one of them is usually large and clawed. This petal is called standard or “Vexillum” The two lateral ones, which are free are called as “Wings” and two anterior inner most fuse to form a boat shaped structure called the “Keel” or “Carina”.

5- ANDROCIEUM
Stamens (9) +1 i.e 9 fuse to form a round sheath around the pistil while tenth is free.

6-GYNOECIUM
Monocarpellary, ovary unilocular, ovule numerous on marginal placenta.

7-FRUIT
Legume or pod.

8-SEED
EX-albuminous.

FLORAL FORMULA

+ , Q , K(5) , C 1+2+(2) , A(9)+1 , G1

ECONOMIC IMPORTANCE

The family is of considerable importance, as a source of high protein food, oil and forage as well as for ornamental purposes. Chief importance lies in the pulses, belonging to this family. All types of pulses (Dalls) are actually the seeds of this family which are rich in protein.

1- FOOD & FORAGE

  • Cicer arietinum (Gram)
  • Pisum sativum (Pea)
  • Lens esculanta (Masure)
  • Phaseolus aureus (Mung)
  • Phaseolus mung (Urad/Mash)
  • Phaseolus vulgaris (kidney bean/Lobia)
  • Medicago sativa alfalfa (Lusan)
  • Vicia
  • Melilotus & Trifolium

2- FURNITURE & BUILDING PURPOSE

  • Butea
  • Dilburgia

3- OIL EXTRACTION
Arachis hypogea (Peanut/Moongphali)

4- DYES

  • Indigofera tinctoria (Neel)
  • Butea monosperma (Yellow dye)

5-MEDICINAL PURPOSE

  • Glycyrrhiza glabra (Cough & cold treatment)
  • Clitoria termatea (Snake bite treatment)

6- ORNAMENTAL PLANTS

  • Lathyrus
  • Lupinus
  • Clitoria
  • Butea
  • Abrus precatorious, used by jewellars as weights called “Ratti”.

IMPORTANT FAMILY MEMBERS

BOT-NAME……………….COMMON NAME………………..LOCAL-NAME
1- Lathyrus Odoratus………..Sweet pea………………….Matter
2- Arachis Hypogea………….Peanut…………………….Moongphali
3- Cicer Arietinum………….Gram………………………Channa
4- Dalbergia Sisso………….Red-wood…………………..Shesham
5- Pisum Sativum……………Edible pea
6- Sesbania aegyptica……….Sesbania

FLORAL DIAGRAM

FROM TEXT BOOK BIOLOGY-XI Pg # 191

6-POACEAE

ALTERNATE NAME

GRAMINAE/ GRASS FAMILY

HABIT AND HABITAT

  • The species are most numerous in the tropics but they are also abundant in temperate region.
  • This family is monocot (one cotyledon in seed)
  • Mostly annual or perennial herbs or shrubs.

VEGETATIVE CHARACTERS

1- ROOTS
Adventitious, fibrous or fascicled.

2- STEM
Cylindrical, Conspicuous nodes and hollow, although solid stems are also found as sugar cane.

3- LEAF
Legulate, alternate leaf sheath mostly open sessile, lamina narrow and ribbon shaped.

FLORAL CHARACTERS

1- INFLORESCENCE
Compound spikes.

2- FLOWER
Sessile, bracteate, incomplete, bisexual or unisexual and zygomorphic.

3- PERIANTH
It is combined structure instead of calyx and corolla. Number 2 or 3 membranous scales called “ Lodicules”

4- ANDROECIUM
Usually 3 stamens, filaments long, free anther versatile.

5- GYNOECIUM
Tricarpellary, syncarpous though only one is functional, unilocular, single ovule, style short 2-3, stigma feather like.

6- FRUIT
Grain or coryposis.

7- SEED
Endospermic, monocotyledonous.

FLORAL FORMULA

+ or O , O or O or O , P2 (lodicules) , A3 or 0 , G1 or 0

ECONOMIC IMPORTANCE

The family poaceae has great importance than any other family of flowering plants.

1- FODDER AND FOOD STUFF

  • Triticum indicum
  • Avena sativa
  • Zea mays
  • Oryza sativa
  • Hordeum vulgare
  • Pennisetum typhoideum

2- SUGAR MAKING

  • Saccharum officinarum (sugar cane)

3-PAPER MANUFACTURING

  • Certain species of Grasses

4- VEGETABLES & SOUP DISH

  • Sugar cane
  • Bamboo-shoots

IMPORTANT FAMILY MEMBERS

BOT-NAME…………………………COM-NAME…………………….LOC-NAME
Triticum Indicum……………………..Wheat……………………….Gandum
Avena Sativa…………………………Oats
Zea Mays…………………………….Indian corn………………….Makai
Oryza Sativa…………………………Rice………………………..Chawal
Saccharum Officinarum…………………Sugar cane…………………..Ganna
Hordeum Vulgare………………………Barly……………………….Joo
Pennisetum Typhoideum…………………Bajra
Bambusa Arundinacea…………………..Bamboo………………………Banns
Cymbopogon Jawarancuza……………………………………………..Lemon Grass
Cynodon dactylon…………………………………………………..Lawn Grass

FLORAL DIAGRAM

FROM TEXT BOOK BIOLOGY-XI Pg#196)

DOUBLE FERTILIZATION

  • After pollination, the tube nucleus of the pollen grain forms pollen tube, while generative nucleus divides into two male (sperm) gametes.
  • When pollen tube reaches the embryo sac through micropyle, one of the male gametes fuses w/t egg cell and forms “oospore (zygote)”,it develops into seed. Another male gamete fuses with definitive nucleus and forms “Endospermic nucleus”, w/c develop into endosperm of seed or food storage tissue of seed.
  • Because two times fertilization occurs so it is called “Double fertilization”.

THE FLOWERS

The flower is a modified shoot and meant for sexual reproduction. It is collection of four different kinds of floral members, arranged in four separate whorls. The upper two whorls are essential or reproductive whorls whereas lower two are helping or accessory whorls. The flower is born on an axis which consists of two parts the pedicel or stalk of flower and the thalamus is swollen end of the axis on which the floral leaves are inserted. The floral whorls are arranged on the thalamus in a particular order one just above the other. These four whorls are as follows.

CALYX

It is the first or lower most whorl of the flower, the calyx is generally green is colour. Each member of calyx is known as sepal. Sometimes sepals become coloured called petaloid. Such as in gold mohur. The calyx is non essential or accessory part of flower.

FUNCTIONS
1- Protection of floral bud
2- Assimilation when green in colour
3- Attraction when coloured and showy
4- Modified into papus which helps in dispersal

COROLLA

It is the second non essential floral whorl of flower. It is brightly colored. Each member of its known as petal. However there is no differentiation of calyx and corolla in some flowers. It is called perianth.

FUNCTIONS
1- The corolla attracts insects and hence help in pollination.
2- It encloses stamens and carpels.
3- It protect the stamens and carpels from external heat rain and insects attack.

ANDROCIEUM

It is the third essential floral whorl and each member of it is known as stamen. The stamen is a male reproductive body and consists of filament, anther and connective. The anther bears four chambers of pollen sacs, each chamber is filled with granular mass of small cells called pollen grains. Each pollen grain consists of two walls, the outer exine and inner intine.

FUNCTIONS
It is the male reproductive body and hence possess male gametes which take part in reproduction.

GYNOECIUM

It is the fourth essential floral whorl and its component parts are called carpals. The carpel is a female reproductive body, it may be one or more than one, and may be united or free. Each carpel consists of stigma, style and ovary. The stigma is terminal end which receives the pollen grain. It may be smooth or hairy and becomes sticky on maturity, The style is slender projection of ovary, It helps in pollination and later on dries up. The ovary is swollen basal portion, which encloses minute egg like bodies called ovules. The ovule possess egg cells.

FUNCTIONS
The gynoecium is a female reproductive body. It possess the egg cells which take parts in reproduction.

AESTIVATION

It is the arrangement of floral whorls i.e. the sepals or petals in a floral bud, it is of following types:

(A) VALVATE
The members of a whorl lie close to each other and do not overlap e .g Calatropis.

(B) TWISTED
One margin of a floral whorl overlaps that of the next one. It may be clockwise or anti clockwise e.g. China rose.

(C)VEXILLARY
When petals are five, two internal are overlaped on both margins by two petals, these two are overlaped by a single largest posterior petal e.g. Pea bean etc.

(D)IMBRICATE
When one of the sepal or petal is internal and other external and each or remaining one is overlaped on one margin and it overlaps the next one on other margin e.g Gold mohur .
A. Velvate.
B Twisted
C. Vexillary
D. Imtricate.

INSERTION OF FLORAL LEAVES ON THE THALAMUS

The floral leaves are inserted on the thalamus in a particular order, it is of following types:

(A) HYPOGYNOUS
In some flowers the thalamus is convex or conical and ovary occupies the highest position on it. However other floral whorls are inserted below the ovary, such flower is known as hypogynous and ovary as superior. E.g. Mustard.

(B ) PERIGYNOUS
In certain flowers thalamus forms a flattened circular disc due to the fact that sises of thalamus grows up to the same level. The apex of thalamus is in the middle of the disc at which gynoecium develops, whereas at the rim or margin sepals, petals and androecium are inserted. They are round about it and hence are called perigynous, such as in pea. Sometimes the apex of thalamus grows up in conical shape as in raspberry. Whereas in some cases the calyx forms a cup shaped structure called calyx tube such as in wild rose.

(C) EPIGYNOUS
In some flowers the concave receptacle surrounds the ovary and is fused with it. The sepals, petals and stamens apparently arise from the tip of the ovary such ovary is said to be inferior. E.g. Sunflower, apple, guava, pear etc.

IMPORTANT TERMS TO DESCRIBE A FLOWER

COMPLETE: When all the four floral whorls are present.
INCOMPLETE: When any of the whorl is absents.
BISEXUAL: The stamen and carpel both are present.
UNISEXUAL: The flower possess either stamen or carpel.
STAMINATE: Only stamens are present (male).
PISTILATE: When flower possess only carpels (female).
NEUTER: The stamens and carpels both are absent.

SYMMETRY

+ACTINOMORPHIC
When a flower can be divided into two equal halves by any vertical section passing through centre.

+ ZYGOMORPHIC
When it can be divided into two similar halves by only one vertical section.

+ IRREGULAR
The flower can not be divided into two similar halves by any vertical plane.

COHESION OF STAMEN

+ MONOADELPHOUS
When filaments are united in a bundle and anthers are free e.g. China rose.

+ DIADELPHOUS
The filaments are united into two bundles and anthers are free e.g. Pea.

+ POLYADELPHOUS
The filaments are united into more than two bundles and anthers are free.

+ SYNGENECIOUS
The anthers are united together and filaments are free e.g. Sunflower.

ADHESION OF STAMENS

+ EPIPETALOUS
The stamens adhere to corolla, wholly or partially by their filaments.

+ GYNANDROUS
When stamens adhere to carpels e.g. Calatropis.

LENGTH OF STAMENS

+DIDYNAMOUS
The stamens are four, two of them short and two long e.g. Nerium.

+TETRADYNAMOUS
The stamens are six but two short and four long e.g. mustard.

GYNOECIUM

+ MONOCARPELLARY
The pistil consists of only one carpel, it is also known as simple pistil e.g. Pea, Bean

+ POLYCARPELLARY
The pistil consists of two or more carpels, it is also known as compound pistil e.g. Rose.

+ SYNCARPOUS
The carpels are united into one ovary e.g. Mustard.

STIGMA

+ CAPITATE
When stigma is rounded and knob like. Bi, tri or Multified: when stigma is branched into two , three or many.

+ FEATHERY
When stigma is feather like.

+ FLATTENED
When sitgma is flat.

+ POINTED
When stigma is pointed.

+ LINEAR
When it is long and narrow.

STYLE

+ TERMINAL
When style arise from top of ovary; such as in Mustard.

+ GYNOBASIC
When it arise between the lobes of the ovary from its base;such as in Salvia.

+ PEDICILLATE
When flower is born on a stalk or pedicel. (STALKED)

+ SESSILE
When stalk is absent

+ BRACTEATE
When flower is developed in the axil of a bract

+ EBRACTEATE
When bract is absent.

+ DIMEROUS
When each floral whorl has two floral leaves (Dicot)

+ TRIMEROUS
When floral whorl has three floral leaves (Monocot)

+ TETRAMEROUS
When each floral whorl has four floral leaves; and so the pentamerous Dicots)

CALYX

+ PETALOID
The calyx having other then green colour.

+ CAMPANULATE
Sepals fused to form bell shaped structure.

+ POLYSEPALOUS
When sepals are free from one another.

+ GAMOSEPALOUS
When sepals are fused or united with one another.

PETALS

+SEPALOID
The petals are green in colour.

+CRUCIFORM
Petals are arranged in form of a cross.

+POLYPETALOUS
When petals are free from one another.

+GAMOPETALOUS
When petals are united with one another.

+PERIANTH
When calyx and corolla can not be distinguished with one other due to similar shape and colour.

PERIANTH

+SEPALOID
When perianth leaves are green.

+POLYPHYLLOUS
When perianth leaves are free from one another.

+GAMOPHYLLOUS
When perianth leaves are fused.

FLORAL FORMULA
The floral formula is represented by various symlols. The symbols used in floral formula are as follows.

SYMMETRY OF THE FLOWER

Zygomorphic = +
Actinomorphic = O

SEXUALITY

  • Bisexual = Q+
  • Unisexual (male)
  • Unisexual (female)
  • Neuter =

PERIANTH

  • Perianth = P
  • Polyphyllous = Pn n=number of perianth leaves.
  • Gamophyllous = (n) “ “ “

CALYX

  • Epicalyx = Epi K
  • Petals = C
  • Calyx = K
  • Polypetalous = Cn,
  • Polysepalous = Kn, n= number
  • Gamopetalous = C(n)
  • Gamosepalous = K (n) of sepals

ANDROECIUM

  • Androecium = A
  • Androecium free = An n= number of stamens
  • Androecium United = A (n)
  • Epipetalous = C-A

GYNOECIUM

  • Gynoecium = G
  • Apocarpous = Gn
  • Syncarpous = G (n)
  • Ovary inferior = G
  • n= number of carpels
  • Ovary Superior = G

FLORAL DIAGRAM
The features of flower in flora formula are represented by symbols, while in floral diagram by the diagram of its various floral leaves alongwith actual number and position.
MOTHER AXIS: It is represented by a Dot above the floral diagram. It actually shows the position how a flower is born. The position of it can be seen from upperside. It may be between two adjacent sepals or a single sepal.

PLACENTATION

It is the arrangement of placenta which are cushion like ridges in the ovary, The placenta bear ovules. In simple ovary placentaion is marginal, whereas in compound ovary it may be parietal, axile, free central, basal and superficial.

(A) MARGINAL
In a simple ovary or monocarpellary pistil, the ovules are arranged along the fused margins, these margins forms a cushion like tissue called placenta along the ventral suture on the inner surface of ovary wall e.g. Pea, Gram, Bean, etc.

(B) PARIETAL
In a compound syncarpous and unilocular ovary, the fused margins of the carpals swells up to form placentas, to which ovules are attached. The placentas lie along the wall of ovary and their number indicates the number of carpels forming ovary e.g. cucumber, Melon; etc.

(C) AXILE
In a polycarpellary syncarpous pistil and multilocular ovary, each carpel is folded along its mid-rib and meets in the centre of the ovary. The ovules are attached to this central axis e.g. Tomato, China rose, etc.

(D) FREE CENTRAL
In a compound and unilocular ovary the ovules are situated all around the central axis, which arise from the thalamus and not fused with the margins of the carpels. However in some plants the axile placentation becomes free central due to breaking down of septa e.g. Pink (Diantus)

(E) BASAL
In a unilocular ovary the placentas develops directly on the thalamus and bears single ovule at the base of ovary e.g. Sunflower, Cosmos etc.

(F) SUPERFICIAL
In a multilocular ovary, the ovules are not on the margins of the carpels; but over the whole inner surface of the partition walls e.g. Waterlily.

TYPES OF PLACENTATION

1.FOR SIMPLE OVARY
Only one type, MARGINAL.

2.FOR COMPOUND OVARY
I- Exile
II- Central
III- Parietal
IV- Basal
V- Superficial.

1. MARGINAL PLACENTATION
In marginal placentation, the ovary is one chambered and the placenta develops along the junction of the two margins of the carpel, called the ventral suture.

EXAMPLES
Pea, wild pea, gram, gold mohr, and cassia are common examples.

2. AXILE PLACENTATION
In the axile placentation the ovary is two to many chambered and the placenta bearing the ovules develop from the central axis e.g. Potato, Tomato, Petunia, China rose etc.

3. CENTRAL PLACENTATION
In this case the septa in the young ovary soon break down so that the ovary becomes one-chambered and the placenta develops all round the central axis e.g. Dianthus, Saponaria etc.

4. PARIETAL PLACENTATION
The ovary is one chambered and placenta develops on the inner wall of the ovary e.g. papaw, orchids etc.

5. BASAL PLACENTATION
The ovary is unilocular and placenta develops directly on the thalamus e.g. sunflower, cosmos etc.

6. SUPERFICIAL PLACENTATION
The ovary is multilocular, carpels are numerous and placenta develops all round the inner surface of the partition walls as in waterlily.

INFLORESCENCE

The branch system of the floral region bearing a group of flowers is called INFLORESCENCE. The term inflorescence refers to the arrangement of flowers on plant.

TYPES OF INFLORESCENCE

The flowers may be solitary or grouped into clusters, Such clusters vary in shape and arrangement. On the basis of arrangement of flowers, inflorescence is classified into

1-RECEMOSE

1- In this case, the main axis of inflorescence does not end in a flower.
2- Main axis continues to grow and gives off flowers laterally.
3- The lower or outer flowers are always older and open earlier than the upper or inner ones.
4- Order of opening of flowers is called centripetal.

EXAMPLES
Mustard, Gold mohr, Mulberry, birch etc.

KINDS OF RECEMOSE INFLORESCENCE

Recemose inflorescence has following main types on the basis of nature and shape of the peduncle:

I- PEDUNCLE ELONGATED
It is further subdivided into following types;

1. RECEME
The main axis in this case is elongated and it bears laterally a number of flowers which are all stalk e.g. radish, mustard, dwarf gold mohur etc.

2. SPIKE
In this case the flowers are sessile e.g. Adhatoda, Achyrnthes etc.

3. CATKIN
This is a spike with a long and pendulous axis which bears unisexual flowers e.g. Musberry, Acalypha, Birch and Oak etc.

4. SPADIX
This is also a spike with a fleshy axis which is enclosed by one or more large bracts called spathes e.g. Banana, Palms etc.

II- PEDUNCLE SHORTENED
It is further divided into following types;

1. CORYMB
Here the main axis is comparatively short, and the lower flowers have much longer stalk than the upper ones. Hence all the flowers are brought more or less to the same level e.g. candytuft, wall flowers etc.

2. UMBEL
Here the primary axis is short and it bears at its tips a group of flowers which have pedicles of more or less equal length so that the flowers are seen to spread out from a common point. In the umbel there is always a whorl of bracts forming an involucre, and each flower develops from the axil of a bract, e.g. Carrycumin, Coriander etc.

III- PEDUNCLE FLATTENED
The best example is seen in sunflower family, here the inflorescence is called the head as the capitulum.

HEAD OR CAPITULUM
1. A dense cluster of sessile or sub-sessile flowers, on a compound receptacle is called capitulum.
2. Main axis is almost flat, bearing sessile flowers.
3. Outer flowers are older and open earlier.
4. The florets are commonly of two types
I- RAY FLORETS
II- DESC FLORETS
EXAMPLES
Capitulum is characteristic feature of sunflower family e.g. sunflower, marigold; zinnia, cosmos etc.

IV- SPIKELET INFLORESCENCE
It is a kind of racemose inflorescence. There are three bracts at its base called glumes. The lower two without flowers are called empty glumes. The third glume has flower in its axil and called Lemma. Just opposite to lemma, there is small bractcole called Palea. Flowers are covered by their respective lemma and palea. This type of inflorescence is characteristic feature of family Poaceae (Grass Family).

2-CYMOSE

1- Here the main axis ends in a flower and similarly the lateral axis also ends in a flower.
2- The growth of each axis is checked due to presence of flower on its tip.
3- The terminal flowers are always older and open earlier than the lateral ones.
4- The order of opening of flowers is centrifugal.

EXAMPLES
Jasmine, Teak, Night Jasmine, Ixora.

KIND OF CYMOSE INFLORESCENCE

I- UNIPAROUS (MONOCHASIAL) CYME
Main axis soon ends into a flower and produces only one lateral branch at a time ending in a flower. The succeeding lateral branches again follow the same mode of producing flowers. If the succeeding branches are produced on alternate side, it is called Scorpiold cyme (cotton, forget-me-not). Whereas, if the succeeding branches are produced on same side, it is called Helicoid (sundew).

II- BIPAROUS (DICHASIAL) CYME
Main axis soon terminate into a flower and produces two flowers. This mode is followed by each succeeding flowers (Pink, Night- Jasmine).

POLLINATION

It is the process of transference of pollen grains to the stigma of the flower.

TYPES OF POLLINATION

Pollination is of two types.
1- Self pollination or Autogamy.
2- Cross Pollination or Allogamy.

(A)SELF POLLINATION
It is the transfer of pollen grains from the anther of a flower to the stigma of the same flower.

METHODS OF SELF POLLINATION
In self pollination, only one flower is concerned to produce the offspring. Irrespective whether the flower is unisexual or bisexual self pollination can take place by two methods

I-HOMOGAMY
In homogamy the anther and the stigma of a unisexual flower mature at the same time. In rare cases it may takes place by insects or wind.

II- CLEISTOGAMY
In cleistogamy the flower never open. They remain closed and the pollination takes place in the closed flower such as in pansy (viola), balsam (impatiens), oxalis, etc.

B)CROSS POLLINATION
It is transfer of pollen grain from the flower of one plant to the stigma of flower of another plant of the same species.

METHODS OF CROSS POLLINATION
It takes place by external agencies. These agents are insects, animals, birds, wind and water.

I- ENTOMYPHILY
The pollination takes place by insects. It is of general occurrence in plants.

II ANEMOPHILY
The pollination is brought about by wind.

III HYDROPHILY
The pollination takes place in aquatic plants particularly the submerged ones, through the medium of water e.g. Hydrilla and vallisneria

IV ZOOPHILY
The pollination is carried out by birds, squirrels, snails etc. Examples are Bombax and Erythrina.

Fahim Patel

By Fahim Patel

Fahim Patel is the Content Manager of guesspapers.net. A graduate from Karachi University, he has intensive experience in content production.

Comments

comments

Leave a Reply

Your email address will not be published. Required fields are marked *


*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>