This document discusses the use of anatomical features of plants for resolving taxonomic problems and elucidating phylogenetic relationships. It describes various anatomical features that have been studied, including trichomes, stomata, leaf anatomy, nodal anatomy, cellular contents, wood anatomy, and flower anatomy. Specific examples are given of how studies of these anatomical features have helped classify plants and solve taxonomic controversies by distinguishing between genera, species, and sometimes families. The document advocates that anatomical studies provide important evidence that can be used alongside other data for systematic and phylogenetic studies of plants.

1. Presented by…
Patel Hasti G.
M.Sc. Sem 2
Botany CBO 405
Roll No 207
Department of Life Sciences
H.N.G.U. Patan

2. Content :
 Introduction
 Vegetative organ:
1] Trichomes as criteria and it’s types
2] Stomata as criteria and it’s types
3] Leaf anatomy
4] Nodal anatomy
5] Cellular content
6] Wood anatomy
• Reproductive organ :
1] flower anatomy

3. Introduction
 Anatomical feature of vegetative as well as
reproductive organs have been studied to help in
studies on particularly for resolving controversial
taxonomic problems.
 In fact, such studies have been successfully
employed for the solution of taxonomic problem
and to the elucidation of phylogenetic relationship.
 In several cases, anatomical studies have helped in
identifying the fragmetary material which lacked
flowers and fruits in the herbarium specimen.

4. Cont…
 Several internal feature of the plants have been
found important in systematic studies.
 A few are discussed here after dividing them into
two broad categories,
1. Anatomy of vegetative organ
2.Anatomy of reproductive organ

5. 1.Vegetative organ :
A] Tricomes as criteria
 Heintzelman and Howard (1944) supported the
segregation of two genera ottoschulzia and poraqueiba
of Icacinaceae on the basis of the evidence from
trichomes.
 Controversy about the link between typheceae and
sparganiaceae could be resolved on the basis of
presence of sessile or glandular trichomes.
 Inamdar (1967)confirms the position of Nyctanthes
within family oliaceae on the basis of structure and
ontogeny of trichomes.

6. Types of Trichomes:
A B C D E
Sr no Types of trichomes examples
A Star shape Goccypium herbaceum
(malvaceae)
B Unicellular Raphanus sativus
C Multicellular Helianthus anus (asteraceae)
D Multicellular branched Withania somnifera ( solanaceae)
E Glandular Ocimum sentcum (lamiaceae)

7. B] Stomata as criteria:
 Vesque (1889) classified stomata into four categories
which he named after in which these were found.
 Von cotthem (1970) proposed a detailed account of
classification of stomata based on the number and
position of subsidiaries
 Krisnamurthy and Kannabiran (1970)have successfully
used structure of stomata for identification of
fragmentary material in the pharmacognostical studies.
 Pant and Mehra (1965) and Bir and coworker (1971)
supported the division of Rubiaceae into three
subfamilies Rubioideae, cinchonoideae and
Guettaroideae.

8. Cont…
 Kothari and Sah ( 1974,75 ) while studying taxonomic
and phylogenetic significance of stomata in the
Papilionaceae proposed that tribes like Sophoreae
Podalyrieae and Gensteae should be considered more
primitive due to presence of anomoperigenous and
anisomesoperigenous stomata then Dalbergieae and
Phaseoleae.
 The ontogenic studies on stomata of Caricaceae and
Cucurbitaceae suggest close relationship between
them due to presence of anisomesoperigenous and
aperiginous stomata in both these family.

9. Types of stomata:

10. C] Leaf Anatomy :
 Carlquist (1961) has rightly stated that “The leaf is
perhaps anatomically most varied organ of
angiosperms and its anatomical variations often concur
closely with generic and specific and occasionally
familial lines.”
 the leaf anatomy is one of the most reliable characters
useful in grass systematics .
 govindrajalu (1969) was able to formulate a key to
distinguish various species of cyperus on the basis of
leaf anatomy.
 Ayensu (1974) has shown the Vellozia and Barbacenia of
velloziaceae can be distinguished from each other by
the form of sclerenchyma in the leaves.

11. Cont…
 A considerable amount of studies on leaf anatomy in
relation to taxonomy have been made by Wunderlich
(1950), Hagerup (1953), Fahn (1954), tomlinson (1959)
Culter ( 1965) and Metcalf (1968).
Cyperus brevifolius cyperus rotendus Cyperus pepyrus

12. D] Nodal Anatomy :
 Sinnott (1914) recognised three fundamental types of
nodal anatomy in Dicotylelons A] unilacunar, B]
trilacunar and C] multilacunar.
 Morsden and Bailey (1955) discovered to fourth type of
nodal anatomy unilacunar two trace.
 A comparative study of nodal anatomy may also be
valuable for showing relationships of genera or even
species.
 Bailey and Howard (1941) proposed that on the basis of
nodal structure the subfamily Icacinoideae of
Icacinaceae may be divided into two difference sections,
one section characterized by having trilacunar nodes
and other by having unilacunar nodes.

14. E] Cellular Contents :
 Many types of chemical deposits such as plastids,
starches, proteins, tannins and crystals and other
mineral deposits occur in plant tissues.
 The distribution pattern of the cells containing
chloroplast and other types of plastids is of systematic
value.
 Reichert (1913) has shown that a care study of starch
grains of particular groups may reveal generic species
and even variable criteria.
 Deposition of silica, calcium oxalate, calcium carbonate
and other chemical substances is characteristic of
certain taxa and they have been found of systematic
value.

15. Cont…
 Epidermal cells containing large silica bodies are of
systematic use both at generic and specific level in
Zingiberaceae, Musaceae , and areceae .
 Robarth (1900) found calcium oxalate cryctals is useful
in comparing species of Eichhornia. In some cases
crystoliths are also helpful in linking related families
e.g. Mpraceae, Urticaceae, and canmabinaceae.
• The presence and absence of tanninifarous cells in the
cells in the root cortex of related families respectively is
useful systematic criterion.

16. F] Wood Anatomy :
 Carlqueist(1961) stated that the well established
trends of xylem evolution should be taken into
account by any systematist interested in
formulating relationships or evolutionary status of
angiosperm taxa.
 The various features which have been used as
follows:
i] Vessels :
 Vessels found solitary are considered as primitive
than those aggregated in groups such as pore
multipales, pore clusters and pore chains.

17. Cont…
 Similarly non porous
wood is no more
primitive in which
vessels are not found
than porous wood and
diffuse porous wood is
more primitive than
ring porous wood.

18. ii]Wood Parenchayma
Apotracheal Paratracheal
Diffuse Banded Terminal Vasicentric Abaxial
Aliform Confluent

20. iii] Rays :
 Feature like rays abundance,
ray dimension, width and
cellular composition, degree
of wall thickness of ray cells,
pitting in ray parenchyma and
homogenous and
heterogenous nature have
been variously used for
taxonomic and phylogenetic
studies.
 It is believed that
heterogenous rays are
primitive than homogenous
rays.

21. iv] Storied Structured:
 The term refers to the arrangement of cells or tissues in
horizontal series as seen in tangential section.
 Storied structures are considered advanced over the
ones with non stratified cells.
Wood anatomy has also played an important role in
solving certain taxonomic problem. A few them are
mentioned here :
1] Engler and Prantl(1889) proposed amintiferae as least
specialised group but Hutchinson(1959), Cronquist
(1968), and Takhtajan(1969) consider Magnoliales as
most primitive group.

22. Cont…
2] Hutchison(1959) placed Annonaceae in separate order
Annonales whereas Takhtajan (1969) placed it under
order Magnoliales. Purkayastha (1980) studied wood
anatomy of the family and found that annonaceae have
much advanced type of wood than magnoliales and
thus he supported Hutchinson in this respect.
3] Studies of Purkayastha (1980) on calcium oxalate
crystals found in wood of family Sapotaceae reveal that
the two genera of the family, Manilkara and Mimusops
cannot be morphologically distinguished but they can
be separated on the basis of chembered crystalliferous
strands of calcium oxalate.

23. 2] Reproductive organ
7] flower anatomy:
A flower has typical vascular ground plan, i.e.
sepals receive three distinct vascular traces , petals
and stamens received a single traces and carpels
three traces each.
During the course of evolution and specialization
of flower, the vascular plan has undergone
reduction, amplification cohesion and adnation of
vascular bundles.
Floral anatomy has played important role in solving
taxonomic problem may be the cases of Trapa and
Ruppia.

24. cont…
 Role of floral anatomy in phylogenetic problems has
also been found valuable and hence advocated e.g. the
fact that families like menispermaceae ,
calycanthaceae, and anonaceae have originated from
ranunculaceae is supported by the organization of
floral vasculature.
 Similarly, the general vascular plan of flower and the
course of placental bundles particularly in
caryophyllaceae and the polimoniaceae suggest that the
latter have been derived from the caryophyllaceous
stock.
 Studies have floral anatomy of family solanaceae and
scrophulariaceae suggest that the two families show
great affinity in the presence of anatomically pariatel
placentation and in the uniformity of vasculature of the
gynoecium

26. References :
A Text Book f Botany – Plant Anatomy and Economic
Botany Volume-III
By: S N Pandey
A Chadha
Anatomy of Seed Plants
By : V Singh
P C Pande
D K Jain
www. Systematic plant anatomy .com