Venation and its types

Definition of venation
types of venation
daigram

1. Venation
Morphology Of Leaf

2. What is Venation ?
The arrangement of the veins and veinlets in
the lamina of a leaf is called Venation.
There are two types of Venation
1)Parallel Venation
2)ReticullateVenation

3. Parallel Venation :
In this type of venation many veins , about equal in size
, run parallel to each other from the base to the apex
of the leaf or from the midrib outward to the margin
of the leaf.
Kinds of parallel venation
a) Unicostate:If there is one midrib in the lamina it is
called unicostatevenation.
b) Multicostate:If many midribs are present in the
lamina of the leaf it is called Multicostate

4. Types of Multicostate Parallel
Venation:
Multicostate
is further classified in to two types
•Convergent:If in Multicostate parallel
venation the midrib converge towards apex it
is called as multicostateConvergent.
•Divergent: If the midribs diverge towards the
margin of the leaf as in Fan-Palms.

5. Types of Reticulate Venation :
Reticulate Venation: In this type of venation there
may be one or more midribs from which smaller
veins branch off and form a conspicuous network.
It has following kinds;
a) Unicostate:If the leaf has single midrib from
which lateral branches arise which run toward
the margin of the leaf example , mango , peepal,
guava.

6. Cont.…
•b) Multicostae: If many midribs present all
about equal in size arising from one point at
the base of lamina.

7. Types of Multicostate Reticulate
Venation:
Multicostate has further two kinds;
a) Convergent:when midrib arises from the
base of the leaf and converge towards the
apex is called convergent venation.
b) Divergent:When midrib arises from the base
of the leaf and diverge towards the margin of
the leaf e.g. Castor oil plant.

8. Daigram: