Samacheer Class 11 Bio Botany - Taxonomy and Systematic Botany

Botanical Gardens play the following important roles.
* Gardens with an aesthetic value attract a large number of visitors. For example, the Great Banyan Tree (Ficus benghalensis) in the Indian Botanical Garden at Kolkata
* Gardens have a wide range of species and supply taxonomic material for botanical research.
* Garden is used for self-instruction or demonstration purposes.

* Two cotyledonous plants are kept under Dicotyledonou
* Cup-shaped thalamus is a unique feature of the series Thalamiflorae of subclass
Polypetalae:
* Class
* Dicot
* Subclass
* Polypetalae
* Series
* Thalamiflorae

Molecular taxonomy using molecular markers like RAPD’s etc helps in establishing the relationship between the members of different taxonomic groups at the DNA level. Thus it helps to unlock the evolutionary history of organisms.

JSolanaceae (Dicot) Morphology
Liliaceae (Monocot) Morphology
Bulbous stem / rhizome / corm absent but stem tuber present eg. Solarium tuberosum
Bulbous Stem – Lilium
Rhizome -Polygonatum
Corm – Colchicum Occur
Radical leaves Cariscup } Absent from roots
Radical leaves present eg. Lilium
Leaves alternate & exstipulate
Slipules absent exstipulate fleshy and hollow
Flowers – Pentamerous
Flowers – Trimerous
Calyx_ – Persistent -Solanum melongena
Calyx, Corolla – Absent
Corolla of various shapes present
Perranth is only present
Stamens – 5 – Epipetalous
Stamens – 6 – In a whorl of three each apostamenous
Carpels:
* Ovary superior
* bicarpellary, bilocular
Carpels oblipuely placed bicarpellary later become tetra carpellary due to the formation of false septa
Ovary superior tricarpellary trilocular
Fruits – Berry / capsule
Fruits – Loculierdal capsula
Anatomy:
Bi-collateral Vascular Bundles occur
Cambium present Secondary growth present
Anatomy:
Conjoint collateral Vascular bundles
Cambium absent
No secondary growth
Part – B
11th Bio Botany Guide Taxonomy and Systematic Botany Additional Important Questions and Answers
Choose the correct answer:

c) B D A C
VIII. Find out the true and false statements from the following and on that basis find the correct answer:

Gynoecium of Pisum sativum:
* Mono Carpellary
* Unilocular
* Ovules on marginal placentation
* Feathery stigma
Gynoecium of Datura metal:
* Bicarpellary
* Tetralocular
* Ovules on axile placentation
* Bilobed stigma

* Tools aiding Taxonomical study are known as Taxonomical Aids
* There are many types of these Aids keys, Flora, Revisions Monograph, Catalogues,
* Herbarium and Botanical garden
Types:
* Local Flora – Covers limited area sate, Country, City mountain, etc Eg. Flora of Thiruvannamalai District
* Regional Flora – Include large geographical area Eg. Flora of Tamilnadu Carnatic by K.M. Mathew
* Continental Flora – Cover entire continent Eg. Flora of Europaea by D.A. Web
* Electronic Flora – Digital format of flora published online Eg. E Flora of China

• Population of organism closely resemble each other
• Descend from common ancestor
• They sexually interbreed freely producing fertile offspring
• They have morphological resemblance in asexually reproducing organism
• In fossil organisms they are identified by their morphological & anatomical resemblance

ICN’s second principle is that a specimen must be associated with a scientific name known as nomenclatural type (specimen, or its illustration)
Eg. Herbarium sheet: –
There are 7 types
* Holotype:
The original Protologue of the author is a definite source of identity
Citation & submission of it is one of the criteria for valid publication of a botanical name
* Isotype: Duplicate of Holotypes
* Same person on the same date with same field number
* Reliable duplicates of holotype – to be distributed to various herbaria of various region
* Lectotype: Specimen selected from original material may serve as Lectotype when holotype is missing or destroyed
* Syntype: When the author cites more than one specimen in his Protologue without designating Holotype.
* Neotype: Specimen from the non-original collection when original
* Paratype: holotype missing or destroyed: specimen other than Holo, Iso, or Syntype
* Epitope: Specimen or illustration serves as an interpretive type when all the above types are ambiguous.

Species is the lowest taxon in classification. It is defined as the group of individuals which are closely resembling each other and interbreed among themselves producing fertile offspring.

• Commonly used & accepted for phylogenetic classifications.
• Produces a hypothesis about the relationship of organisms to predict the morphological characteristics of an organism.
• Help to elucidate the mechanism of evolution.

* Introduced by Gaspard Barhin
* Implemented by Carolus Linnaeus
* Scientific name of a plant consists of 2 words.
* First one is Genus name
* Second one is Species name.
* Genus Species
Eg: Mangifera – Genus – indica – Species

APG Classification
Bentham & Hooker’s Classifications
Kingdom
Plantae
Kingdom
Plantae
Clade
Angiosperm
Class
Dicotyledonae
Clade
Eudicots
Sub class
Polypetatae
Clade
Rosids
Series
Calyaflorae
Order
Fabales
Order
Rosales
Family
Fabaceae
Family
Fabaceae

• Most recent classification of flowering plants
• Done in last decade of 20th century
• All these provide data with respect to DNA seqences of 2 chloroplast genes (extrachromosomal) (atp B and r bcL) and one nuclear gene (nuclear ribosomal 18 s DNA).

Taxonomy:
* The discipline of classifying organisms into taxa
* Governs the practices of naming, describing, identifying and specimen preservation.
* Classification + Nomenclature = Taxonomy
Systematics:
* Broad field of biology that studies the diversification of species
* Governs the evolutionary history and phylogenetic relationship in addition to taxonomy
* Taxonomy + Phylogeny = Systematics

• Collection of collected, pressed and dried plant specimens preserved, then mounted on a sheet of paper is referred to as Herbarium.
• It also refers to the Institution where many such Herbaria are preserved.
• Eg. Royal Botanical garden Kew London.

1. Biosystematics: Biosystematics is an “Experimental, ecological and cytotaxonomy” through which life forms are studied and their relationships are defined.
2. Aims of Biosystematics: The aims of biosystematics are as follows:
* To delimit the naturally occurring biotic community of plant species.
* To establish the evolution of a group of taxa by understanding the evolutionary and phylogenetic trends.
* To involve any type of data gathering based on modem concepts and not only on morphology and anatomy.
* To recognize the various groups as separate biosystematics categories such as ecotypes, ecospecies, cenospecies, and comparium.

Linnaeus classification is mostly based on sexual characters like number, union, length and distribution of stamens and also on carpel characters. Hence it is called sexual system of classification.

International Herbarium
Herbarium
Year Established
Acronym
Number of specimens
1.Museum National d’Historie Naturelle, Paris, France
1635
P,PC
10,000,000
2. New York Botanical Garden, Bronx, New York, U.S.A
1891
NY
72,00,000
3. Komarov Botanical Institute, St.Petersburg (Leningrad), Russia
1823
LE
71,60,000
4. Royal Botanic Gardens, Kew, England, U.K
1841
K
70,00,000

Herb
Indigofera, crotalaria
Prostrate herbs
Indigofera enneaphylla
Erect herb
Crotalaria verrucosa
Shrubs
Cajanus cajan
Small trees
Sesbania
Climbers Large trees
Clitoria sp Pongamia, Dalbergia
Woody climber
Mucuna
Hydrophyte
Aeschyno mene aspera

• Provides resource material for systematic research & studies
• A place for the orderly arrangement of voucher specimens
• Voucher specimen serves as a reference for comparing doubtful Newly collected fresh specimen
• Voucher specimens play a role in
• Studies like floristic diversity
• Environmental assessment
• Ecological mechanisms &
• Survey of unexplored area
• provides an opportunity for documenting biodiversity and studies related to the field of ecology & conservation biology.

• Increased knowledge of chromosomes Have been used for extensive biosystematic studies & resolving many taxonomic problems.
• Cytological especially chromosomal characters such as number, size, morphology and behaviour during meiosis are of taxonomic value.

1. Diadelphous – Stamens (9) + 1-9 Stamens united 1 free
2. Diadelphous – (5) + (5) – Stamens in 2 bundles of 5 each.
3. Monoadelphous but dimorphic – Out of 10 stamens 5 are with longer flaments longer anther 5 are with shorter Flaments and short anthers known as Dimorphic

• Study of various chemicals available in plants help to solve the certain taxonomical problem
• Chemotaxonomy scientific approach of classification of plants on the basis of their biochemical constituents
• Proteins – (more controlled by genes less subjected to natural selection)
• So used at all hierarchical level of classification starling from variety to division.
• Other chemicals studied are – Amino acids, nucleic acids – peptides

Regional Flora from continental flora.
* Regional Flora: Flora covering a large geographical area or a botanical region Ex: flora of Madras Presidency.
* Continental Flora: Flora covering the entire continent. Ex: flora of Europaea.

• Conserved molecular sequences helped to identify
• DNA data help in – investigation of evolutionary patterns
• DNA taxonomy – play vital role in, understanding
• phytogeography – help in genome mapping & bio deversity Conservation
• DNA based Molecular markers – used for designing DNA based molecular probes

Family Fabaceae
Family Solanaceae
Family Liliaceae
Butea frondosa (Flame of the forest) Clitoria tematea (sangu – flower)
Cestrium diumum – day Tulipa suaveolens — Tulip Jasmine)
Petunia hybrida Agapanthus african us garden petunia (African only
Five Marks

• A scanner like the UPC of supermarket things, – DNA barcoding is a taxonomical device to distinguish one species from another.
• A very short genetic sequence from a standard part of a genome is used as a DNA tag or barcode to identify a plant
• Paul Hebert proposed it and so-known as the Father of barcoding.

• Helps in the identification and classification organism
• Aids in the mapping the extend of bio-diversity
• Eventhough it require a large data base of sequences for comparison & prior knowledge of the barcoding region, it is helpful tool to determine the authenticity of botanical material in whole, cut or powdered form.

• In Arachis hypogea after fartilization, the stipe of ovary become meristematic and grows down into the soil.
• The ovary gets buried into the soil and so we call the fmit as groundnut.

Stipule
Stipel
Pulvinus
The compound leaf has a stipule a green scale like structure from which the leaf originate
It is a small scaly structure at the base of the leaflet of compound leaf
The R achis and petcole of the leaf, and leaf lets have swollen, this condition is known as Pulvinus

Habit – Twining climber
Root – Branched tap root system
Stem – Aerial weak stem, twiner
Leaf – Imparipmnately compound, Petcolate, Alternate, stipulate,
Leaf lets stipellate, stipels are pulvinate reticulate venation
Inflorescence – Solitary and Axillary
Flower -Zygomorphic Bracteate, Bracteolate (large) Bisexual complete
Dichlamydeous – Pedicellate, Pentarnerous & Hypogynous
Calyx – 5 sepals synsepalous valvate aestivation odd sepal anterior in position
Corolla – 5 petals apopetalous
1 standard petal -(Vexillum)
2 wing petals -(aiea)
2 keel petal(carina) – united at the base in descendingly imbricate aestivation
Androecium – 10 stamens diadeiphous
(9) + 1 (i.e.) nine united one free in 2 + bundleš
Anther – Dithecous, basifixed introse and devisce by Longitudinal Division
Gynoecium – Made up of ovary style & stigma
Ovary – Superior with a prominent stipe monocarpellary, unilocular with many ovules on marginal placentation
Style – simple incurved
Stigma – feathery
Fruit – Legume
Seed – non endospermous reniform

Phylloclade
Cladodo
(aerial sterm or branch modification)
Eg. Ruscus
Branch is modified. leaves reduced to scales
(aerial sterm modification)
Eg Asparagus
Aerial sterm is modified, leaves reduced to scales

Habit – Large erect, stout, herb
Root – Branched tap root system
Stem – Hollow, herbaceous strong odour
Leaf – Simple, alternate, petiolate, entire or deeply lobed glabrous, exstipulate unicostate reticulate venation
Inflorescence – Solitary & Axillary cyme
Flower – Actinomorphic, (Regular) Bracteate, Bracteolate, Bisexual Complete Dichlamydeous Pentamerous, sessile & hypogynous
Calyx – 5 sepals synsepalous
Valvate aestivation persistant
Corolla – 5 petals synpetalous plicate 10 lobed Twisted aestivation funneishaped
Androecium – 5 stamens – epipetalous altemi petalous.
Anther – dithecous, basifixed, introse longitudinal dehiseence
Gynoecium – Superior – bicarpellary bilocular,
Ovary – syncarpous basically bilocular later become tetralocular due to the formation of false septa Carpels obliquely placed ovules on swollen axile placentation
Style – simple long flu form
Stigma – bibbed
Fruit – Spinesent capsule opening by four apical valves persistent calyx
Seed – Endospermous

The aims of chemotaxonomy:
* To develop taxonomic characters which may improve the existing system of plant classification.
* To improve present-day knowledge of the phylogeny of plants.

Habit – Perrennial herb with bulb
Root – Fibrous adventitious root system
Stem – Underground bulb
Leaf – Radical leaves cylindrical fleshy with sheathing leaf bases & parallel venation
Inflorescence – scafrigerous, pedicels of equal length arising from apex of peduncle
Flower – Small white
Actinomorphic,
Bracteate, eBracteolate Bisexual Complete
Monochiamydeous.
Trimerous – hypogynous
Flowers – Protandrous
Perianth – 6 Tetals in 2 whorls of 3 each syntepalous Valvate acstivatíon
Androecium – 6 stamens in a whorls of 3 each epipelatous
apostamenous
Anther – Dithecous basifixed, introse and longitudinal dehiscence
Gynoecium
Ovary – Superior, tricarpellary trilocular 2 ovules in each locule on axile
placentation
Style – simple, slender
Sligma – simple
Fruit – loculicidal capsule.