MADE BY:- Himanshu Bhatt
*
Contain
Morphology
The Root
Modification Of Root
Functions Of Root
Rootless Plant
Plants that are all Roots
*
*
* Plant morphology (morphe-form+logos-study) is
a branch of Botany which deals with the study
of forms and features of different plant organs
like roots, stems, leaves, flowers, seeds, fruits
etc., including there development
*
* The root is that green cylindrical part of a
plant which is given rise by radicle , the first to
come out as a descending organ during
germination of a seed
*
* Root Cap
* Meristematic zone
* Zone of Elongation
* Root Hair
* Zone of Mature Cells
*
* Root cap is a thimble- shaped or cap like
protective structure present at the tip of root
apex covering the root meristem.
* It is a parenchymatous and multicellular .
* The root cap secrets mucilage that lubricates
the passage of root through the soil.
* The soft and tender root would be unable to
penetrate the hard soil if the root cap is absent
.
*
* It is a small region(about 1mm in length) positioned
subterminally behind the root cap.
*
Meristematics zone or zone of cell division consists
of isodimetric meristematics cells arranged closely
or compactly and therefor, represents the growing
point or zone of the root.
* The Meristematic zone
continuously produces new
cells that are added outwards to the root cap and
inward to the basal region of the root resulting in
the longitudinal growth of the root
*
* Lying
just behind the meristematic zone, the
zone of elongation is about 4-8mm in length
and is made up of newly produced cells by
growing point.
* The cell of this zone lose the power of division
but elongate rapidly thus increasing the length
of the root.
* The cell of this zone possess the power of
absorption of water and mineral salts from the
soil.
*
* Root hair zone is also called zone maturation
or differentiation as the cells of this zone
undergo maturation and differentiation into
different type of primary tissues of the root,
e.g., epiblema, cortex, endodermis, pericycle,
phloem, xylem, etc.,.
*
* In aquatic plants root hair are usually absent.
* Mycorrhizal roots lack root hair.
* The number of root hairs are over 35,000 per
square cm of root surface and many billions
per plant.
*
* Laying behind the root hair zone, the zone of
mature cells constitutes the bulk of the root.
* The outermost layer of it consists of thick
walled or impermeable cell do not undergoing
any further change.
* The important function of this zone is to help
anchoring the plant firmly in the soil and to
give rise to lateral roots from the
interior(pericycle).
*
* Tap Root System
* Adventitious Root System
*
* Given birth by radicle of the embryo.
* Always underground.
* Consist of single primary root.
* Primary root produces distinct secondary roots,
tertiary roots, and rootlets in acropetal
succession.
* Primary root is persistent.
* It ay be surface feeder or deep feeder.
*
* Given birth by any part of the plants other
then radicle of the embryo.
* May be underground or aerial.
* Consist of roots forming a cluster.
* Primary root absent and there is no any type
of distinction.
* Primary root though develops but is shortlived.
* If underground it is usually surface feeder.
*
The tap root modify for the storage of food
called storage or fleshy roots. The primary root
is swollen due to stored food in it and the
secondary root remain thin.eg., carrot(Daucus
carota), shalzum(Brassica rapa), chukander(Beta
vulgaris)
*
STORAGE OR FLESHY
TAP ROOTS
RESPIRATORY ROOTS
*
* The secondary , tertiary or some time the
primary root in leguminaceous plants bear
small nodule-like swellings.
* These swellings are called root nodules or
tubercles that contain nitrogen-fixing
bacteria (namely, Rhizobium
leguminosarum).
* The bacteria pick up the free nitrogen
occurring in the soil atmosphere and convert it
into organic compounds of nitrogen.
* This relationship is beneficial for both the
bacteria and leguminous plant and therefor, is
called mutualistic symbiosis( or reciprocal
symbiosis).
*
* Normally the adventitious
root are fibrous and
surface feeder( eg., cereals, grasses) but in
some cases they get modified to perform
special functions like storage food, mechanical
support and vital activities .The modification
of adventitious roots are as follow………………
*
Fleshy adventitious roots:- like tap roots
sometimes the adventitious roots swollen and
become thick due to storage of food. Depending
upon there shape and place of swelling s, these
roots are classified in to following categories:1. Tuberous(single root tubers) roots
eg., sweet potato(ipomoea batata)
2. Fasciculated roots
eg., Asparagus, Dahlia
*
1. Prop roots
Prop roots arise from large horizontal
branches of the tree.
They hang down in vertical position.
After entering into the soil, these root give
piller like appearance and do not terminate
into fibrous root system.
Eg., Banyan tree(ficus benghalensis)
*
2. Stilt roots
Stilt roots develop from the basal nodes or
the stem near the soil.
They develop obliquely from the stem.
After entering into the soil, they terminate
into the fibrous root system.
Eg., Pandanus, Zea mays etc.,.
*
BANYAN TREE
1.Primary functions
Anchorage
Absorption of water and minerals
Preventions of soil erosion
2. Secondary functions
Storage of food
Providing mechanical support
Help in floating
Help to climb
*
* Many hydrophytic plants e.g., Utricularia,
Wolffia, Myriophylleum etc., Do not develop
any roots as they need little absorption of
water & minerals salts that is fulfilled by the
general surface of the plants itself.
* Aldrovanda is also rootless angiosperm.
*
CONTENT
Stem
Buds
Forms of stem
Modification of stem
Function of stem
*
* Stem can be define as that ascending
part of
the main axis(shoot axis) of plant which
develop form the plumule of the embryo and is
usually negatively geotropic and positively
phototropic.
*
* Stem grows in length by means of terminal buds.
* It is clearly differentiated into nodes and
internodes.
* When young, the stem is green and
photosynthesizes.
* When mature, the stem bears flowers and fruits.
* It may bears hair on external surface which are
commonly multicelluar.
*
* A buds represents a condensed immature or
embryonic shoot possessing a growing point
enveloped by closely place immature leaves.
However, a buds can be defined as a compact
young shoot consisting shoot stem overlapped
by crowded immature leaves surrounding the
growing point.
*
1.On the basis of there nature
vegetative
Floral
Mixed
2. On the basis there position
Terminal
Lateral
Adventitious
*
* Areal stem
Reduced stem:-
Here the stem is very much
reduced to a small disc which lies above the
base of the root and is non photosynthetic.
E.g., radish(raphanus sativus ) etc.
Weak stem:- Here the areal stem are delicate
thin, weak and thus are unable to erect. e.g.,
lableb , pasiflora etc.
*
* Underground stem:- Underground subterranean
stem are those that lies below the surface of
the soil. They are not aerial, non green, store
food and contribute in perennation. E.g.,
Banana( musa paradisiaca) .
*
1. Prostrate or sub-aerial week stem
Trailers(=stragglers)., the main stem and its
branches of some sub-aerial weak stem trails
or spread horizontally along the ground without
producing roots at intervals.
Creepers :- are those prostrate or sub-aerial
weak stem whose main stem and its branches
trails or spread horizontally along the ground
producing root at interval.
*
* Upright weak stem modification
Twiners :- These stem are long flexible and twin
around and upright – support like rope by a special
type of growth movement (eg. Convolvulus arvensis
). The twiners can be considered as of sinistrorse type and of dextrose-type.
Cilimbers:- contrary to the twiners that twin on
the support by their own growth movement, the
climber require the help of certain clasping of
clinging structure(eg., Tendrils, Spines, Thorns,
Hooks).
eg., Smilax, Piper, Bignonia etc.
*
* Underground stem modification
Sobole is an underground- runner. It does not swell
as it does not store any food material and remains
thin. Eg., Agropyron, Imberata(Ulau grass).
Sucker
 It is underground modify thin stem.
 It may be said as runner like and underground
runner .
 It is apex of the sucker that grows into an aerial
shoot.
*
Rhizome
 Rhizome is well developed and well branched
underground modify stem.
 Food material is stored in entire stem and
branches.
 Rhizome is placed generally obliquely or
horizontally in soil.
 Roots are produced all along rhizome. Eg,.
Ginger.
*
* Primary functions
 stem bears and supports foliage, flower and
fruits.
Leave manufacture the food which is
translocated through the phloem of the stem
to root, fruit and storage organ.
*
Modification of stem for: a)storage (b) support (c)protection (d)spread and
vegetative propagation
* Secondary functions
Stem store food in their parenchyma
cells
and underground modified form. Eg.,
Potato(solanum tuberosum), Ginger(zingiber
officinale), Banana(musa paradisiaca).
The underground stems like those of
dryopteris, mentha etc. functions as orgons of
perennation to overcome unfavourable
conditions.
*
CONTENT
Leaf
Kind of leaves
Types of leaves
Phyllotaxy
Leaf modification
Function of leaf
*
* Leaf is a green
lateral
flattened outgrowth borne
on the node of a steam or
its branches and is
characteristically
photosynthetic. Leaves
originated from the shoot
meristem as leaf primordia
and gradually enlarge . They
are the most important
vegetative organ of the
plant as they synthesize
food in them.
*
* Cotyleadonary leaves:- these are the
embryonic leaves(cotyledons) emerging at the
time of seed germination. Two cotyledonary
leaves are present in dicots while only one in
monocots.
*
* These leaves contain flower or inflorescence in
there axil and are called bract leaves. Usually
they are small and green but exceptionally in
some plants are large and bright coloured.
*
* Photosynthetic normal leaves borne on
areal
stem or its branches are called foliage leaves.
The word leaf is normally used to refer to the
foliage leaves.
*
* Leaf base(=hypopodium):-
it is lower most part of the
leaf borne onto node of the
stem. Usually the leaf base
is border to get sufficient
base base for attachment
onto the node.
*
* Petiole(mesopodium) stock of the leaf that
connect the lamina with the stem or its
branches is called petiole. The upper part of
the petiole remains embedded in lamina in the
form of midrib while its lower parts is attached
with the stem in the form of leaf base.
*
* Lamina(=epipodium) lamina is the terminal,
thin, flattened, green and conspicuous part of
a leaf and is specialized to manufacture food.
Each leaf possesses its own shape, to margin,
one apex and two surface.
*
* Venation refers to the arrangement of veins
and veinlets in the lamina . Veins and veinlets,
in addition to the forming the structural frame
work of lamina or blade.
*
* Reticulate venation :- the vaniation is
reticulate when veinlets is are irregularly
distributed and for a network or reticulum in
the lamina. It is the characteristic feature of
dycotyldons.
*
* Parallel venation:- it is also called sriate
venation. In it, all the veins are run parallel to
each other and do not any network. Parallel
venation is the characteristics of the
monocotyledons.
*
* Simple leaf
The lamina of the simple leaf do not divided
into distinct lobes or leaflets.
An axillary bud occur In the axil of simple
leaf.
Simple leaf develop in acropetal succession on
the stem.
This may borne on the stem in one or more
planes.
*
* The lamina is distinctly divided into two or
more leaflets borne either at the tip of the
petole or laterally on the rachis.
* An axillary bud may be present in the axil of
the whole leaf but never in the axil of leaflets.
* Leaflets are always borne in the one plnae.
*
* Pinnate compound leaf:- In this type of
compound leaf, the leaflets are borne laterally
on an elongated axis which may be the midrib
or lateral vein of a simple leaf.
*
* Palm of hand like outline
* Leaflet originated from common point
*
* Phyllotaxy is refers to the arrangement of leaf
on the stem or its branches.
* Type of phyllotaxy
 Alternate:- Only one leaf is borne on each
node and the leaf of adjacent nodes roughly
lie toward the opposite side thus giving a spiral
arrangement.
Opposite:- In opposite phyllotaxy, two leaf
are borne on each node lying always opposite
to each other.
*
Whorled
or verticillate :- In whorled
phyllotaxy, the three or more then three leaf
are borne on a single node is whrol or circle.
*
* Though the main function of leaves is the
photosynthesis , a leaf or its parts is
occasionally modified into specialized
structures to perform some other functions.
Which are as follow :-
*
* Tendrils are wire like sensitive structure that
help the plants in climbing by coiling around a
support. They are usually unbranched.
*
* In some plants, the leaves or the parts of
leaves are transformed into spines that
protect the plant from grazing animals and
reduce the rate of transpiration particularly in
xerophytic plants.
*
* Leaves or lamina of
some insectivorous
plants get modified into
pitcher to trap insects
e.g., Nepenthes,
Dischidia etc.,
*
* Primary function of leaves:Photosynthesis:-it is the most significant single
function of a leaf by which the latter synthesizes
food material for plant.
Transpiration :- leaves are the main seat of
transpiration which create force or tension in the
water column to cause ascent of sap.i.e.,
translocation of water or minerals from soil to the
top of the plants via Xylem channel.
Exchange of gases:- leaves exchange gases from
and to the atmosphere mainly through stomata
present on them.
*
* The branch on which the flower are arised is
called peduncle, it develop in axile of leaf or
on the terminal branch of the plant .The term
pidcel is use to the stalk of each individual
flower, attached to the peduncle. The specfic
mode of arrangement of a group of flower on
the peduncle is called inflorescence.
*
* The inflorescences are classified on the basis of
position in the shoot system into the following
fourtypes:
1. Terminal inflorescence: A strictly terminal
inflorescence, terminates the growth of the
branch.
2. Axillary inflorescence: It is terminal on a
short axillary branch, which is reduced to an
inflorescence.
*
3. Intercalary inflorescence: These are terminal
clusters that have been left behind by continuing
apical growth of the main axis, which form
alternately fertile and sterile sections.
Example: Callistemon (Bottle brush)
4. Cauliflory: The development of inflorescences on
older branches.
Example: Theobroma cacao (Cocoa plant),
Arctocarpus (Jackfruit), Cannon ball tree.
*
* On the basis of sequence of development of
flowers on the peduncle the inflorescences are
of thefollowing kinds:
1. Racemose (Indefinite or indeterminate)
2. Cymose (definite or determinate)
*
*
Different types of racemose inflorescence(a) simple raceme (b) spike
(c) catkin (d) spadix(e) corymb (f) umbel (g) capitulum (h) panicle
S.No Character
Racemose Cymose
01.
Peduncle
It does not end in single
flower instead grows
continuously.
02.
Position of Flower are arised laterally Flower actually arised terminally
flower on in all sids on the
in one side only.
peduncle peduncle.
03.
Arrangem- The flower are arranged
ent of
in an acropetal manner.
flower
The flower are arranged in a
basipetal manner.
04.
pollanation
A pollyinator can not pollinate
many flower in one visit though
flower are grouped more
frequently
*
A single visit by a
pollinator can pllinate a
large no. of flower.
It ends up into a single flower.
CONTAINT
flower
calyx
corolla
androecium
gynoecium
*
* Flower is the most beautiful
part of angiospermic plant and
arise latterally or terminally
and the axile of leaf which
itself arises from the node. It is
the reproductive unit in
angiosperm.
*
* Actinomorphic flower:- when flower is radially
symmetrical, it is termed as actinomorphic.
* Zygomorphic flower:- when flower is bilaterally
symmetrical , it is termed as zygomorphic
flower.
* Hermaphrodite or monoclinous flower:-a flower
is called bisexual when it contain both male
and female reproductive organs.e.g.;china rose
mustard etc.
*
* Cyclic and acyclic flower:-when the floral part of
flower arranged in a whorl, the flower is caled
cyclic, and if floral part are arranged spirally and
not in whorl, the flower is called acyclic.
* Complete or incomplete flower:-when the flower of
aplant have same size ,colour ,and arranged of
various floral whorl/organs, then flower are called
regular and if any flower of plant shows
dissimilarity in any of it’s part of trait , then the
flower is called incomplete.
*
*
* It form the outermost covering of a
dichlamydous flower. The unit of calyx are
called sepals.each sepls is green ,coloured
leaflike structure in most of the cases.
* When the sepals of flower are free from each
other , the condition is called polysepalous.
* When the sepals of flower are fused with is
other, the condition is called gamosepalous.
*
* It occurs next to calyx in a dichlamydous
flower. It is a colorful structure other then
green, thus help in insect pollination to the
flower. The unit of corolla is called petals .
* When all petals of flower are fused , the
condition is called gamopetalous.
* When all petals of flower are free from each
other , the situation is called polypetalous.
*
* Aestivation: The mode of arrangement of
sepals or petals in floral bud with respect to
the other members of the same whorl is known
as aestivation.
*
(i) Valvate: The sepals/peta ls close to each
other without overlapping or may be in contact
with each other.
(ii) Twisted: Overlapping is regular, i.e., one
margin of the sepal/petal overlap the next
member and the other margin is overlapped by
the previous.
*
(iii) Imbricate: Out of five sepals/petals one is
completely internal being overlapped on both
margins and one is completely external with the
rest of the members arranged as in twisted
aestivation.
(iv) Quincuncial: Out of five sepals/petals two
are completely internal, two external and one
has one margin external and theother margin
internal.
*
(v) Vexillary: Out of five sepals/petals the
posterior one is the largest and external almost
completely covering two lateral members which
in turn overlap the two small anterior
sepals/petals
*
* Types of aestivation in corolla :
(a) Valvate (b) Twisted (c) Imbricate
(d) Vexillary
* It is a collective term given to group of
stamens or male reproductive organs present in
flower. Each stamen has two part a long
filament and a terminally situated bag shaped
anther. Most of the anther of angiospermic
plant are dithecous, i.e., have two lobes but
some have only one lobe, i.e.,
monothecous,e.g. China rose.
*
* Anthology is known as the study of flower.
* The term staminode is given to non-functional
stamens.
* A stamen is a modified leaf (microsporophyll)
*
* The pollen grains are produced in pollen-sacs. A
sterile stamen is called staminode.
* Stamens of flower may be united with other
members such as petals or among themselves.
* When stamens are attached to the petals, they
are epipetalous as in brinjal, or epiphyllous
when attached to the perianth as in the flowers
of lily.
*
* The stamens in a flower may either remain free
(polyandrous) or may be united in varying degrees.
* The stamens may be united into one bunch or one
bundle (monoadelphous) as in china rose, or two
bundles (diadelphous) as in pea, or into more than
two bundles (polyadelphous) as in citrus.
* There may be a variation in the length of filaments
within a flower, as in Salvia and mustard.