Structure of the flower

Floral structure, inflorescence, fruits, palynology, fertilization

1. Calyx
Corolla
Gynoecium
Androecium

2. •A flower, sometimes known as a bloom or
blossom, is the reproductive structure found
in flowering plants (plants of the division
Magnoliophyta, also called angiosperms). The
stalk of the flower is called the pedicel and is
swollen at the tip forming the receptacle.

3. Sepals, petals and stamens
arranged at the base of
the ovary in a convex
receptacle (superior
ovary)
The sepals, petals,
stamens and ovary
lie in the same
plane.
The sepals, petals and
stamens are placed
above the ovary
(inferior ovary)

4. Calyx
The outermost whorl consisting of units called sepals.
Types Based on Fusion
Polysepalous: free sepals or in other words, the sepals are not fused.
Gamosepalous: fused sepals, either wholly or at the base only.
Corolla
The next whorl, composed of units called petals,
which are colored to attract insects that help
the process of pollination.
Types Based on Fusion
Polypetalous: Flowers having free petals.
Gamopetalous: Flowers have fused or united petals.

5. 1. Achlamydeous without perianth.

1. Chlamydeous with perianth
2. Monochlamydeous only one whorl

2. Diplochlamydeous two whorls
3. Homochlamydeous: (tepals).
Undifferentiated into calyx nor corolla
3.Heterochlamydeous
Differentiated into calyx and corolla

6. 1. Units meet without overlapping …….…………...…..Valvate
1. Units overlapped……………………………………......……Imbricate
2. Units overlapped all in the same direction…….Contorted
2. Units overlapped not in the same direction
3. Each unit overlapping the one posterior to
it…..................................................Ascending
3. Each unit overlapping the one anterior to
it..................................................Descending
3. Two units out, two in and one unit over- and under-
lapping………………………………….….….. Quincuncial

7. Aestivation

8. Androecial Types Based on Fusion of Parts
Apostemonous:
With separate stamens.
Monadelphous:
With one group of stamens connate by filaments.
Diadelphous:
With two groups of stamens connate by filaments.
Polydelphous:
With several groups of stamens connate by filaments.

11. Gynoecial Types Based on Fusion
Apocarpous:
With carpels separate.
Syncarpous:
With stigmas, styles, and ovaries
completely fused.

12. Style Types Based on Insertion
Gynobasic:
Attached at base of ovary in central depression.
Terminal:
attached at the end of the ovary.
Style Types Based on Branching
Simple: one style from one carpel.
Single: one style from more than one carpel.
Free: branched style.
Stigma Types Based on Shape
Capitate: Head-like. Lobed: Divided into lobes.
Plumose: Feathery

13. 1. Ovary more than one locule,…………………..……..Axile
1. Ovary one locule
2. One ovule
3. Placenta at the base of the ovary…………...…..Basal
3. Placenta at the top of the ovary……...........…..Apical
2. Many ovules
4. Placenta on ventral suture of the ovary…....Marginal
4. Ovules on ovary peripheral walls………...…Parietal
4. Ovules on the central placenta……....….Free central

15. Orthotropous or Atropous.
Straight body; funicular attachment
is at one end and micropyle at other.
Campylotropous.
Curved body on one side; micropyle
is near medially attached funiculus.
Anatropous.
Completely inverted; funiculus is
attached basally near adjoining micropyle area.

16. Perfect or bisexual
Flowers having both carpels and stamens.
Imperfect or unisexual
Flowers lack one of the reproductive organ.
Monoecious
Unisexual flowers are found on the same individual plant but in
different locations.
Dioecious
Unisexual flower is found only on
separate individuals.

17. Actinomorphic (Regular)
If the perianth is bisected through the
central axis from any point, symmetrical
halves are produced.
Zygomorphic (Irregular)
When flowers are bisected and produce
only one line that produces symmetrical
halves.

18. A.Racemose
Main axis not arrested or terminated by a flower:- Racemose, Indefinite, Acropetal, Ascending or Centripetal.
1. Simple, with main axis unbranched:-
2. Flowers pedicellate
3. Of somewhat equal length on a
comparatively elongated axis…..…..Raceme
3. The lower ones longer than the
upper and the main axis short……..Corymb
3. Of nearly equal length on an
undeveloped main axis…………..…Umbel

19. 2. Flowers sessile
4. On a comparatively elongated
main axis……………………………..…….Spike
4. A pendulous spike….…………...……….…….Catkin
4. A fleshy spike…………….……….………..….Spadix
4. The main axis condensed………………..…Capituum
1. Compound, with main axis branched once or more
5. Branched racemose…………….Panicle (Compound Raceme)
5. Corymbs corymbose ……………..Compound Corymb
5. Umbels is an umbel…………..…....Compound Umbel
5. Spikes spicate……………………......Compound Spike

20. B. Cymose
Main axis arrested and terminated by a flower:- Cymose, Definite, Basipetal, Decending or Centrifugal.
1. A cyme with only one branch…………………………...
….....Monochasial
2. Branching regularly to one side
only………………………………..…....Helicoid
2. Branching alternately to either
side……………………………...…..…Scorpioid
1. A cyme with two branches……………...…………..……
Dichasial
1. A cyme with more-than two
branches……………………...……...Polychasial

21. C. Special type
1. A pair of opposite cymes seemingly
confluent round the main
axis……………………………….……..Verticillaster
1. Flowers unisexual borne on the
inside of an hollowed out axis or
receptacle, opening to the outside
by an opening guarded by incurved
hairs……………………………….…Hypanthodium
1. A cymose inflorescence reduced to look like
a single flower ; flowers unisexual and naked,
with a single female flower in the centre
surrounded by several male flowers, arising
from the bottom of a cup-like
involucre………………………………...…Cyathium

23. 1.Fruit derived from several flowers...MULTIPLE FRUIT
“Composite”
1. Fruit derived from a single flower
2. Derived from more than one pistil ..............AGGREGATE FRUIT
2. Derived from a single pistil ...................................SIMPLE FRUIT
3. Fruit fleshy, usually indehiscent (not splitting)
4. Flesh of fruit derived from a hypanthium that
surrounds the papery carpels ...........................POME
4. Flesh of fruit derived from the ovary wall
5. Pericarp with an outer fleshy layer and an inner
bony layer (the stone) .................. DRUPE
5. Pericarp without an inner bony layer, more or
less fleshy throughout .............................BERRY

24. 3. Fruit dry at maturity
7. Fruit indehiscent (not splitting open)
8. With one/more wings ....................SAMARA
8. Without wings
9. From a compound pistil
10. Shell hard and bony...........NUT
10. Shell not bony….…..CYPSELLA
9. From a simple pistil, shell not bony
11. Pericarp fused to the
seed ..................... CARYOPSIS
11. Pericarp separable from
the seed ....................ACHENE

25. 7. Fruit dehiscent (splitting open)
12. From a simple pistil (1 carpel)
13. Splitting on two sutures .....................LEGUME
13. Splitting on one suture ......................FOLLICLE
12. From a compound pistil (carpels 2 or more, united)
14. Carpels separating from each other but each
retaining its seed....................SCHIZOCARP
14. Carpels splitting, releasing 1 or more seeds
15. Fruit 2-celled, the two valves splitting
away from a persistent, thin partition
or septum (replum)……….SILIQUE
(SILICULE if short)
15. Fruit 1-several-celled, the partition not
persistent if fruit
2-celled ........................ CAPSULE

26. 1. Perianth absent (naked flower)………..…………..Achlamydeae
1. Perianth present………………..……..…………...….….Chlamydeae
2. One whorl present………………….….…….Monochlamydeae
2. Two whorls present……………..……….…...Diplochlamydeae
3. Perianth undifferentiated…………...Homochlamydeae
3. Perianth differentiated into
clayx and corolla…………………..Heterochlamydeae
4. Petals united, stamens≤ 5,
epipetalous, single style……......Sympetalae
4. Not so…………..……………...…….Archichlamydeae

27. •The study of the different features of pollen grains is
known as Palynology.
•The process of liberation of pollen grains from the anther is
known as Anthesis.
•The mechanism of transference of pollen grains from the
anther to the stigma is known as Pollination.
•while the union of nuclei from pollen grains and ovules is
called Fertilization.

28. A. Pollination takes place internally when the flowers are
closed………………………………….…………..……. Cleistogamy
•AA. Pollination takes place when the flowers are
open……………………………………..……..…….…. Chasmogamy
B. Deposition of pollen on the stigma of the same
flower……………………………....……..Autogamy

(Self
pollination)
C. Pollen deposited directly from the anthers on
to the receptive stigma……….. Direct
CC. Pollen deposited on the stigma by an
external agent…………........….. Indirect

29. BB. Deposition of pollen on the stigma of
another flower……….…..………Allogamy

(Cross pollination)
D. Pollination by another flower of the
same inflorescence on the
same plant…….…………… Geitonogamy
DD. Pollination by pollen from another
plant…………………….……. Xenogamy

30. •A. Anemophyly: Pollination by wind.
•B. Hydrophily: Pollination by the agency of water.
•C. Zoophily: Pollination by the agency of the
animals.
1. Ornithophily: Pollination by birds.
2. Chiropteriphily: Pollination by bats.
3. Melacophily: Pollination by slugs and snails.
4. Entomophily: Pollination by insects.

31. 1. Monads:
Each pollen grain is independent from all others
2. Dyads:
The 4 cells resulting from the meiotic division of one pollen mother
cell are separated into two bicellular masses of pollen grains

3. Tetrads:
All 4 cells resulting from the division of one pmc, remain adhering to
each other (Linear, T-shaped, Square, Tetrahedral).
4. Polyads:
The pollen grains of the same pollen chamber are grouped together into
masses of definite shape, nurnber and arrangement
5. Pollinia:
All pollen grains in the some pollen chamber are united together into one
mass
A. Composition of pollen grains

32. B. Sporoderm stratification

33. C. Exine sculpture
(a)Smooth
Has no ornamentation
(b) Granulose
Minute and sparse granules
(c) Rugulose or worty
Coarse and dense granules or worts
(d) Reticulate
Covered by a reticulum (or network)
(f) Echinate or spiny:
With a number of sharp spines

34. 1. Number:
Mono-aperturate
Bi-aperturate
Tri-aperturate
Hexa-aperturate
Poly-aperturate.
2. Positions
(a) Polar
(b) Equatorial or zono-aperturate
dizono-aperturate.
(c) Global or panto-aperturate
3. Character
(a) Pores
(b) Colpi
(c) Colporate
For example:
Trizonocolpate = The pollen grain has 3 fusiform apertures distributed at equal distances
around the equatorial line.
Polypantoporate = grains have numerous pores scattered allover its exine.

35. Formation of male gametophyte

36. Formation of female gametophyte

37. Double fertilization