The document describes nodal anatomy and phyllotaxy, explaining the structure of shoots, nodes, and leaf traces, as well as the transport of water and nutrients in plants. It details types of phyllotaxy, including alternate, opposite, and whorled arrangements of leaves, along with specific examples and subcategories for each type. The concepts emphasize the importance of leaf arrangement in relation to plant growth and development.

2. NODAL ANATOMY

3. NODALANATOMY
 Shoots consists of stems bearing
leaves.
 The point where the leaf attached to
the stem called Node. ( site of
attachment of leaves to the stem )
 The distance between two nodes on
the shoot is called Vegetative
Internodes.

4. LEAF TRACES
 Leaves must have access to a source of water and
essential minerals.
 This transport of substances takes place in primary
vascular connections between the stem vascular system
and the base of leaves called Leaf traces.
 Leaf traces are composed of protoxylem, metaxylem,
protophloem and metaphloem.

5.  Typically contains transfer cells in both primary xylem
and primary phloem.

6. LEAF GAP
 The continuity of the cylinder of primary vascular tissue
is broken immediately above the position of outward
divergence of leaf trace, leaving a discontinuity is called
Leaf Gap.
 Since, these leaf gaps doesn’t affect vascular system.
 Lateral connectivity between tissues on top and bottom of
the leaf gap is formed, since vascular system connectivity
is breaked due to leaf gaps.

8. PHYLLOTAXY

9. PHYLLOTAXY
 “Phyllotaxis” or “Phyllotaxy” is the arrangement of
leaves on a stem.
 The word phyllotaxy is derived from ancient Greek word.
( Phyllo means leaf and taxis means arrangements )
 Phyllotaxy in mature plants is directly related to the
position & size of leaf primordia produced on apical
meristems of varying size and shape.

10. TYPES OF PHYLLOTAXY
 Based on the number of leaves and arrangement of leaves
from the nodes, the phyllotaxy has various types.
I. Alternate
II. Opposite
III. Whorled

11. Alternate Phyllotaxy
 When only one leaf develops at each node. Eg: Brassica
campestris
 Based on the position of leaves at after particular number
of leaves, alternate phyllotaxy is further subdivided into
two.
a) Distichous
b) Tristichous

12. A) Distichous:
 When 3rd leaf comes over the first one. Eg; Grasses.
B) Tristichous:
 When 4th leaf comes over the first one. Eg; Cypres.

13. Opposite Phyllotaxy
 When a pair of leaves are present just opposite to each
other at each node, eg; Calotropis.
 There are two types in opposite phyllotaxy.
A. Opposite Deccusate
B. Opposite Superposed
A) Oppposite Decussate:
 When two successive pairs of leaves occur at right angle
to each other, eg; Psidium gujava.

14. B) Opposite Superposed:
 When all pairs of leaves occur in same plane. Eg;
Combretum.

15. Whorled Phyllotaxy
 When more than two leaves are arranged in the form of
whorl at each node, the phyllotaxy is called Whorled. Eg;
Hydrilla verticillata, Nerium etc.,