MODIFIED LEAVES SUCH AS LEAF TENDRILS,HOOKS,PITCHER,BLADDER AND SPINY LEAVES

2. Topic :Modifications of leaf
Present by : HASNAIN SARWAR
Roll No.: “4128”

3. What is leaf?
d r . a a r i f
CHARACTERISTICSOFLEAF:
- Leaf is a thin,expanded,green
structure.
- The green colour of the leaf is due to
the presence ofchlorophyll pigmen.
- Itis borne on the stem at thenode.
- An axillary bud is often present inthe
axil of each leaf.
- Ithas limited growth.
- Theyalsocarrytheprocessof
transpiration.
Leaves are green flat structures borne on the stem or
on the branches.

4. Modifications of
leaves(types)
1. Leaf tendril
2. Leaf spines
3. Leaf bladder
4. Leaf pitcher
5. Phyllodes

5. What is modification of leaf?
 The primary function of leaf are photosynthesis and
transpiration
 But in many plants the leaves are modified to perform
some additional functions these are called modified
leaves.

6. MODIFICATIONSOF LEAVES:
d r . a a r i f
1-LEAFTENDRILS:
- Incertain plants having weakstem,
entire leaf or a part of it gets
modified into anelongated, thin,
cylindrical, coiled, wiry,sensitive
structure known as tendril.
- These tendrils help the plantto
climb up on some support.
- Inwild pea (Lathyrus), entireleafis
tendrillar,
- in sweet pea (Pisum sativum)
terminal leaflets are tendrillar,
- in Gloriosa only theleaf apex
modifies into tendril,and
- in Smilax, stipulesbecome tendrillar.

8. MODIFICATIONSOF LEAVES:
d r . a a r i f
2-LEAFSPINES:
- . Leaves of certain plants become
wholly or partially modified for
defensive purpose into sharp,
pointed structures known as spines
- Sometimes only a part of leaf such
as stipules, get modified intospines,
to protect plants from grazing
animals, e.g., Zizyphus and Acacia.
- Inbarberry the leaf itself becomes
modified into a spine; while the leaves
of the axillary bud are normal.

10. MODIFICATIONSOF LEAVES:
d r . a a r i f
3-LEAFHOOKS:
In this the leaves are modified into hooks
and help the plant to climb the support.
- InBignonia unguis-cati (Cat's nail),
the terminalthreeleaflets get
modified into three stiff curved &
pointed hooks which look likecat's
nail.
- They cling to bark of tree (support)
and help the plant for climbing

11. M o r MODIFICATAIONSOF LEAVES
p h o l o g y o f L e a f
d r . a a r i f
4-PHYLLODE:
- Insome plants, petiole becomes flat,
green and leaf like and performs
photo synthesis.Thisis known as
phyllode.
- There are about 300 species of
Australian Acacia, all showing the
phyllode.

12. 5-Insect Catching Leaves
 In insectivorous plants, the leaves are especially
adapted to catch and digest insects to fulfil their
nitrogen requirement. Some of the adaptations are
given below.
 Leaf pitcher:n the pitcher plant (Nepenthes) the leaf
becomes modified into a pitcher. There is a slender stalk
which coils like a tendril holding the pitcher vertical and
the basal portion is flattened like a leaf. The pitcher is
provided with a lid which covers the mouth. The
function of the pitcher is to capture and digest insects.

14.  Leaf bladder:Utricularia is another
insectivorous plant which grows in water.
It bears highly dissected submerged
leaves. Some of the segments of the leaf
are modified into bladders.
 These bladders serve as floats for the
aquatic plants and for trapping the
insects.