The document details the morphology and types of leaves in plants, including their structure, function, and various classifications such as foliage leaves, cotyledonary leaves, and stipules. It discusses aspects of leaf attachment to stems, including terms like cauline and radical insertion, as well as leaf arrangements known as phyllotaxis. Furthermore, the document addresses leaf venation patterns, duration of leaves, and special modifications for survival or reproduction.

1. LEAF
Fatima Zahra

2. LEAF
• A principal appendage
o Of the stem
o On branches of a plant
• Arise from nodes
• Bear lateral buds in their
axils
• Chief photosynthetic organ
• Developed in acropetal
succession
• Exogenous in origin

3. LEAF MORPHOLOGY
Each leaf consists of
 A green, flattened portion,
the lamina
 A petiole, that raises the
lamina to expose it to the
sunlight
 A leaf base, the part of the
leaf through which it is
attached to the stem
Leaf base

4. Chief Types of Leaves
 Foliage Leaves :
ordinary green leaves which carry out photosynthesis
 Cotyledonary Leaves :
 found in seeds and serve as food storage
 Absorb food from endosperms for the growing
embryo
 Scale Leaves :
 Small undeveloped leaves
 Usually sessile
 Rarely green
 Their function is usually protection

5. Chief Types of Leaves
Cotyledonary
Leaves
Foliage Leaf Scale Leaves

6. Chief Types of Leaves
 Bracts and Bracteoles :
 Leaves of flowering shoots
are known as bracts
 They may be
• Scale like or
• Green
 Bear one or more flowers
in their
 axils

7. Chief Types of Leaves
 Floral Leaves :
Specialized leaves which form the
parts of flower. They are
 Sepals
 Petals
 Stamens
 Carpels
They are arranged on thalamus.

8. Stipules
The paired outgrowth
developed at the base of leaves.
A leaf may be
 Stipulate
When stipule is present as in
Rosa indica
 Exstipulate
When stipule is absent as in
Ipomea
Ipomea
Rosa indica

9. Kinds of Stipules
 Scaly Stipules :
 Leafy Stipules :
 Free Lateral Stipules
:
 Petiolar or Adnate
Stipules :
 Axillary Stipules :
 Orcheate Stipules :
 Tendriller Stipules :
 Spinous Stipules:
as in peepal
as in pea
as in cotton
as in rose
as in Victoria
as in polygonum
as in smilax
as in Zizypus jujbe

10. 1. Scaly Stipules
 Small
 Membranous
 Scaly
 Protect young leaves in
bud
 They drop off as the bud
open.
 As in peepal

11. 2. Leafy Stipules
 Large
 Green
 Leaf like
 Manufacture food for
plants
 As in pea

12. 3. Free Lateral Stipules
 Small
 Green
 Standing freely at the base of
leaves one on each side
 As in cotton

13. 4. Petiolar or Adnate Stipules
 Fused laterally with the
petiole
 grow along its some
distance
 Giving winged appearance
 As in Rose.

14. 5. Axillary Stipules
 Stipules are fuse to form a single
stipule
 Lie between stem and petiole
 As in Victoria

15. 6. Orcheate Stipules
 The large stipules fuse
along their margins to
form a hollow tube
orchea
 They surrounds the
stem from node up to
certain height of
internode.
 As in polygonum

16. 7. Tendriller Stipules
 Stipules are modified
into tendrils
 As in Smilax

17. 8. Spinous Stipules
 Stipules are modified into
spines which act as
protective organs
 As in Zizypus jujube.

18. Insertion
Attachment of leaves to the stem or branches is called
insertion.
 Cauline :
If the leaves arise on main stem
 Ramal and Cauline :
If the leaves arise both on main stem and its branches,
e.g., in sunflower.
 Radical :
When leaves arise from a reduced stem e.g., in radish
and onion
Such leaves usually forms a rosette.

19. Insertion
Cauline
Radical
Ramal and
Cauline

20. Phyllotaxis
 The arrangement of leaves on stem is called
phyllotaxis
 Helps to avoid overcrowding of the leaves so that
all leaves get maximum light for photosynthesis
 The phyllotaxis may be:
 Alternate: e.g., Hibiscus rosa-sinensis
 Opposite:
a. Opposite decussate: e.g., Calotropis, Ocimum
b. Opposite superposed: e.g., Guava
 Whorled: e.g., Oleander, Alstonia,

21. Phyllotaxis
Alternate
Hibiscus rosa-
sinensis
Opposite superposed
Guava
Opposite
decussate
Calotropis
(Ak)
Whorled
1. Astonia 2.
Oleander

22. Venation
 Parallal Venation
 Found in monocots e.g., grasses, cereals, onion,
banana
a. Unicostate: If there is a single mid rib in the lamina
b. Multicostate: If more than one midribs are present in
the lamina
 Reticulate Venation
 Found in dicots
a. Unicostate: e.g., in Mango, Peepal etc.
b. Multicostate: e.g., in Castor oil

23. Venation
Unicostate Multicostate Unicostate Multicostate
Parallal Venation Reticulate Venation

24. Duration Of Leaves
 Caducuous:
If the leaves fall very early, as in Opentia
 Deciduous:
If the leaf fall at the end of growing season, as in
Dulbergia sissoo
 Persistent:
If the leaf remain functional on the plant for more
than one season, and the plant is called as
evergreen, as in mango etc.

25. Presence and Absence of
Petiole
 Petiolate:
When a leaf stalk or petiole is present, as in peepal
 Sessile:
When the petiole is absent. As in poppy.
 Sub-Sessile:
When the petiole is extremely small, as in Calotropis.
 Winged:
When the petiole has a small blade on its either side and
has a wing like shape. As in Citrus
 Peltate:
When the petiole is inserted at or near the centre of
lamina, as in lotus

26. Presence and Absence of
Petiole
Petiolate
Sub-Sessile
Sessile
Winged
Peltate

27. Kinds of Leaf
 Simple leaf:
When the leaf lamina is all in one piece e.g., in peepal
 Compound leaf:
 Pinnate Compound leaf
• Peripinnate: if the leaflets are even e.g., Cassia fistula
• Imperipinnate: when leaflets are odd e.g., Rosa indica
 Palmate Compound leaf
• Unifoliate: e.g., Citrus
• Bifoliate: e.g., Bauhinia yunnanensis
• Trifoliate: e.g., Oxalis
• Multifoliate: e.g., Alstonia

28. Kinds of Leaf
Peepal Rose
Cassia fistula
Bauhinia yunnanensis
Citrus
Astonia
Oxalis

29. Special Modification of
Leaves
 Leaf-Tendrils: as in grapes and
sweet pea
 Leaf-Spines: as in Berry
 Leaf-Pitcher: as in pitcher plant
 Leaf-Blade: as in bladder wort
 Phyllods: as in Australian
Acacias

30. Modifications
Leaf-
Tendrills Leaf-
Blades
Leaf-Pitcher
Leaf-Spines Phyllods