3. • A leaf is an organ of a
vascular plant, as defined in
botanical terms, and in
particular in plant
morphology. Foliage is a
mass noun that refers to
leaves as a feature of plants.
• Typically a leaf is a thin,
flattened organ borne above
ground and specialized for
photosynthesis.

4. • Leaves are the powerhouse of plants. In most
plants, leaves are the major site of food
production for the plant.
• Sometimes leaves are divided into two or
more sections called leaflets.
– Leaves with a single undivided blade are called
simple, those with two or more leaflets are called
compound.

6. oLower epidermis – outmost tissue on the
lower side of the leaf; protects the leaf
oUpper epidermis – outmost tissue on the
upper side of the leaf; protects the leaf
oMesophyll – all of the middle tissue of the
leaf
 Palisade layer
 Spongy layer

7. o Vascular Bundles –
supply support for the
leaf; contain the xylem
and the phloem
 Xylem – found in the
vein; transports
minerals and water
from roots to shoots
 Phloem – found in the
vein; transports sugar &
other products of
photosynthesis from
leaves to other parts of
the plant

8. • Cuticle
– Waxy substance that
covers the leaves &
stems
– Waterproof layer that
keeps water in plants
• Stomata
- opening between the
guard cells; allows for gas
exchange and some water
 Guard cells -
specialized cells
surround the stomata
and are shaped like two
cupped hands.

10. • External Anatomy
o Petiole – a thin stalk that connects the blade of
the leaf to the plant’s stem
o Blade – a thin flat part; extends of the end of the
petiole
o Midrib – main vein; continuation of petiole
o Leaf tip- leaf apex of the outer end of the leaf
o Leaf Base – expanded area where leaf attached

11. • Simple leaf = undivided blade with a single
axillary bud at the base of its petiole.

12. • Compound leaf = blade divided into leaflets,
leaflets lack an axillary bud but each compound
leaf has a single bud at the base of its petiole

13. • Palmately Compound - is one in which all the leaflets arise
from a common point at the tip of the petiole.
• Pinnately Compound - a row of leaflets forms on either side
of an extension of the petiole called the rachis

14. • Opposite – A pair of leaves is attached at a node. They are at
the same level(node)
• Alternate – A single leaf is attached at a node. They are the
different level(node)
• Whorled – Three of more leaves are attached at a node.

16. acicular
hastate
falcate
obovate

17. • Crenate
– If a leaf has a Crenate
margin, then the
edge of the leaf has
blunt, rounded teeth.
• Entire
– A leaf that is smooth
all the way around
has an Entire margin

18. • Serrate
– A Serrate margin is
when a leaf has
sharp, "saw-like"
teeth.
• Dentate
– A Dentate margin is
when a leaf has
triangular, "tooth-
like" edges.

19. • Incised
– If a leaf has an
Incised margin, it has
deep, irregular teeth.
• Lobed
– When a leaf has a
Lobed margin, the
leaf has deep,
rounded edges.

20. • Sinuate
– A Sinuate margin
describes the sinuous,
slightly wavy line along
the edge of a leaf.
• Undulate
– When a leaf has an
Undulate margin, it has
extremely wavy lines
along the edge.

21. • Denticulate
– With fine dentition
• Ciliate
– With fine hairs

22. • Acute
-Ending in a sharp,
but not prolonged
point
• Acuminate
-Long-pointed,
prolonged into a
narrow, tapering
point in a concave
manner

23. • Cuspidate
-With a sharp,
elongated, rigid tip;
tipped with a cusp
• Emarginate
-Indented,with a
shallow notch at the
tip

24. • Aristate
-having an awn.
• Mucronate
-ending in a
mucro or sharp
point.

25. • Obtuse
-not sharp or
pointed; blunt.
• Truncate
- having a square
or broad end.

26. • Acuminate
-Gradually narrowing
at the base.
• Acute
-Becoming Gradually
Pointed
• Rounded
-A curved base with
margins that form a
smooth arc.

27. • Oblique
-an asymmetrical base
with unequal size lobes,
attached to the midvein
at different levels.
• Cordate
-is a heart-shaped.
• Sagittate
-a base with pointed
lobes directed
downwards.

28. • Hastate
-a base with pointed
lobes directed
outwards.
• Truncate
-a broad straight
base, abruptly ending at
right angles to the
midvein