Chapter Taxonomy and 5 Systematic Botany

Plants are the prime companions of Learning Objectives human beings in this universe. Plants The learner will be able to, are the source of food, energy, shelter, clothing, drugs, beverages, oxygen and • Differentiate systematic botany from taxonomy. the aesthetic environment. Taxonomic • Explain the ICN principles and to activity of human is not restricted to discuss the codes of nomenclature. living organisms alone. Human beings • Compare the national and learn to identify, describe, name and international herbaria. classify food, clothes, books, games, • Appreciate the role of morphology, vehicles and other objects that they come anatomy, cytology, DNA sequencing across in their life. Every human being in relation to Taxonomy, thus is a taxonomist from the cradle to • Describe diagnostic features of the grave. families Fabaceae, Solanaceae, and Taxonomy has witnessed various Liliaceae. phases in its early history to the present day modernization. The need for knowledge Chapter Outline on plants had been realized since human existence, a man started utilizing plants 5.1 Taxonomy and Systematics for food, shelter and as curative agent for 5.2 Taxonomic Hierarchy ailments. 5.3 Concept of species – Morphological, Biological and Phylogenetic Theophrastus (372 – 287 BC), the 5.4 International Code of Botanical Greek Philosopher known as “Father of Nomenclature Botany”. He named and described some 500 5.5 Type concept plants in his “De Historia Plantarum”. Later 5.6 Taxonomic Aids Dioscorides (62 – 127 AD), Greek physician, 5.7 Botanical Gardens described and illustrated in his famous 5.8 Herbarium – Preparation and uses “Materia medica” and described about 600 th 5.9 Classification of Plants medicinal plants. From 16 century onwards 5.10 Types of classification Europe has witnessed a major developments 5.11 Modern trends in taxonomy in the field of Taxonomy. Some of the key 5.12 Cladistics contributors include Andrea Caesalpino, John 5.13 Selected Families of Angiosperms Ray, Tournefort, Jean Bauhin and Gaspard Bauhin. Linnaeus ‘Species Plantarum' (1753)

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 124 02-06-2018 15:18:56 laid strong foundation for the binomial 5.1 Taxonomy and Systematics nomenclature. The word taxonomy is derived from Greek Taxonomy is no more classical words “taxis” (arrangement) and “nomos” morphology based discipline but (rules or laws). Davis and Heywood (1963) become a dynamic and transdisciplinary defined taxonomy as “the science dealing subject, making use of many branches of with the study of classification including botany such as Cell Biology, Physiology, the bases, principles, rules and procedures”. Biochemistry, Ecology, Pharmacology and Though there were earlier usages of also Modern Biotechnology, Molecular the term ‘systematics’, only during the Biology and Bioinformatics. It helps latter half of 20th century ‘Systematics’ to understand Biodiversity, Wildlife, was recognized as a formal field of study. Forest Management of natural resources Simpson (1961) defined systematics as for sustainable use of plants and eco “Scientific study of the kinds and diversity restoration.

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

of organisms and all relationships among tuberosus. These two species differ in their them”. Though there are two terms are morphology. Both of them are herbs but used in an interchangeable way, they differ Helianthus tuberosus is a perennial herb. from each other. Genus consist of multiple species which have similar characters but differ 5.2 Taxonomic Hierarchy from the species of another genus. Taxonomic hierarchy was introduced by Example: Helianthus, Tridax. Carolus Linnaeus. It is the arrangement Family comprises a number of genera of various taxonomic levels in descending which share some similarities among order starting from kingdom up to them. Example: Asteraceae. species. Order includes group of families Species is the lowest of classification which show less similarities among them. and shows the high level of similarities Class consists of group of orders which among the organisms. For example, share few similarities. Helianthus annuus and Helianthus

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 125 02-06-2018 15:18:56 Division is the next level of classification Kingdom is the highest level or rank that consists of number of classes. of the classification. Example: Plantae Example: Magnoliophyta.

Rank Ending Example

Kingdom - Plantae Phylum = Division -phyta Magnoliophyta Subphylum = Sub division -phytina Magnoliophytina Class -opsida Asteropsida Sub class -idea Asteridea Order -ales Asterales Suborder -ineae Asterineae Family -aceae Asteraceae Sub family -oideae Asteroideae Tribe -eae Heliantheae Genus - Helianthus Sub genus - Helianthus subg. Helianthus Series - Helianthus ser. Helianthus Species - Helianthus annuus

5.3 Concept of species-Morphological, 3. In sexually reproducing organisms, Biological and Phylogenetic they interbreed freely in nature, Species is the fundamental unit of taxonomic producing fertile offspring. classification. Greek philosopher Plato 4. In asexually reproducing organisms, proposed concept of “eidos” or species and they are identified by their believed that all objects are shadows of the morphological resemblance. “eidos”. According to Stebbins (1977) species 5. In case of fossil organisms, they are is the basic unit of evolutionary process. identified by the morphological and Species is a group of individual organisms anatomical resemblance. which have the following characters. Species concepts can be classified into 1. A population of organisms which two general groups. Concept emphasizing closely resemble each other more than process of evolution that maintains the the other population. species as a unit and that can result in 2. They descend from a common evolutionary divergence and speciation. ancestor.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 126 02-06-2018 15:18:56 Another concept emphasises the product and recommendations of the International of evolution in defining a species. Code of Botanical Nomenclature. ICBN deals with the names of existing (living) Types of Species and extinct (fossil) organisms. The There are different types of species and elementary rule of naming of plants they are as follows: was first proposed by Linnaeus in 1737 1. Process of evolution - Biological Species and 1751 in his Philosophia Botanica. 2. Product of evolution - Morphological In 1813 a detailed set of rules regarding Species and Phylogenetic Species plant nomenclature was given by A.P.de Candolle in his famous work “Theorie Morphological Species (Taxonomic elementaire de la botanique”. Then the species) present ICBN was evolved by following the same rules of Linnaeus, A.P. de Candolle When the individuals are similar to one and his son Alphonse de Candolle. another in one or more features and different from other such groups, they are called morphological species. These ICBN due to specific reasons and in species are defined and categorized with order to separate plant kingdom from no knowledge of phylogenetic history, gene other organisms, is redesignated as flow or detailed reproductive mechanisms. ICN. The International Botanical Congress held in Melbourne in July Biological Species (Isolation Species) 2011 brought this change. The ICN According to Ernest Mayr 1963,“ these stands for International Code of are groups of populations that interbreed Nomenclature for Algae, Fungi and and are reproductively isolated from other Plants. such groups in nature”. ICN Principles Phylogenetic Species International Code of Nomenclature is This concept was developed by Meglitsch based on the following six principles. (1954), Simpson (1961) and Wiley (1978). Wiley defined phylogenetic species as “an 1. Botanical nomenclature is independent of zoological and bacteriological evolutionary species is a single lineage of nomenclature. ancestor descendent populations which maintains its identity from other such 2. Application of names of taxonomic group is determined by means of lineages which has its own evolutionary nomenclatural types. tendencies and historical fate”. 3. Nomenclature of a taxonomic group is based on priority of publication. 5.4 International Code of Botanical 4. Each taxonomic group with a particular Nomenclature circumscription, position and rank can bear only one correct name, the Assigning name for a plant is known as earliest that is in accordance with the Nomenclature. This is based on the rules rules except in specified cases.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 127 02-06-2018 15:18:56 5. Scientific names of taxonomic groups require the use of an identifier from are treated as Latin regardless of their a “recognized repository”. There are derivation. two recognized repositories Index 6. The rules of nomenclature are fungorum and Myco Bank. retroactive unless expressly limited. 19th International Botanical Congress was held in Shenzhen in China in 2017. Codes of Nomenclature Changes accepted by International ICN has formulated a set of rules and Botanical Congress are yet to be published. recommendations dealing with the botanical name of plants. International Vernacular names (Common names) Botanical Congress is held at different Vernacular names are known as common places every six years. Proposals for names. They are very often descriptive nomenclatural changes and changes in and poetic references to plants. Common rules are discussed and implemented. name refer to more than one plant or many Changes are published in their website. plants may have same common name. 18th International Botanical Congress These names are regional or local and are held in 2011at Melbourne, Australia made not universal. Example: Albizia amara . L the following major changes. belongs to Mimosaceae is called as Usilai 1. The code now permits electronic in South Tamilnadu and Thurinji in North publication of names of new taxa. Tamilnadu. 2. Latin diagnosis or description is not mandatory and permits the use of Activity English or Latin for the publication of a Write common name and scientific new name (Art-39). name of 10 different plants around 3. “One fungus, one name” and “one fossil your home. one name” are important changes, the concept of anamorph and telomorph Scientific Names / Botanical Names (for fungi) and morphotaxa (for fossils) have been eliminated. (Previously, Each and every taxon as per the ICN sexual and asexual stages of the fungus/ (species, genus, family etc) can have only fossils were provided with different one correct scientific name. Scientific names). name of a species is always a binomial. These names are universally applied. Anamorph – Asexual reproductive Example: Oryza sativa L.is the scientific stage of fungus. name of paddy. Telomorph – Sexual reproductive stage of fungus. Polynomial Polynomial is a descriptive phrase of a 4. As an experiment with “registration plant. Example: Ranunculus calycibus of names” new fungal descriptions retroflexis pedunculis falcatis caule

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 128 02-06-2018 15:18:56 erecto folius compositis. It means butter Standard form of author’s abbreviations cup with reflexed sepals, curved flower has to be followed. stalks, erect stem and compound leaves. Standard form of Polynomial system did not hold good Author Abbreviation as it was cumbersome to remember and Linnaeus L. use. Polynomial system of naming a G.Bentham Benth. plant is replaced by a binomial system by William Hooker Hook. Linnaeus. Robert Brown R.Br. J.P.Lamarck Lamk. Binomial A.P.de Candolle DC. Binomial nomenclature was first Wallich Wall. introduced by Gaspard Bauhin and it Alphonse de Candolle A. DC. was implemented by Carolus Linnaeus. Scientific name of a species consists of 5.5 Type concept two words and according to binomial ICN’s second principle states that a nomenclature, the first one is called specimen must be associated with the genus name and second one is specific scientific name known as nomenclatural epithet. Example: Mangifera indica. type. A nomenclatural type is either Mangifera is a genus name and indica is a specimen or may be an illustration. specific epithet. This system is in vogue Example: Herbarium sheet for vascular even now. plants. There are different nomenclatural types. Author citation Holotype: A specimen or illustration This refers to valid name of the taxa originally cited by the author in accompanied by the author’s name who protologue. It is a definitive reference published the name validly. Example: source for identity. Citation of holotype Solanum nigrum L. There are two types of and submission of it is one of the criteria author citation. for valid publication of a botanical name. Single author: When a single author Isotype: Duplicate specimen of the proposed a valid name, the name holotype collected from same population by of the author alone is accompanied same person on same date with same field by his abbreviated name. Example: number. They are the reliable duplicates of Pithecellobium cinereum Benth. holotype and may be distributed to various Multiple authors: When two or more herbaria of various regions. authors are associated with a valid Lectotype: Specimen selected from publication of name, their names should be original material serves as a type, when noted with the help of Latin word et or &. no holotype was designated at the time of Example: Delphinium viscosum Hook. f. et publications or if holotype is missing or Thomson. destroyed.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 129 02-06-2018 15:18:56 Syntype: When more than one specimen Example: cited by the author in the protologue 1. a) Flowers cream-coloured; fruiting calyx without designating holotype. enclosing the berry ...... Physalis Neotype: Specimen derived from non- b) Flowers white or violet; fruiting calyx original collection selected as the type, not enclosing the berry ....2 when original specimen is missing or destroyed. 2. a) Corolla rotate; Paratype: Specimen cited in the protologue fruit a berry .....Solanum is other than holotype, isotype or syntype. b) Corolla funnel-form or salver-form; Epitype: Specimen or illustration serves fruit a capsule: ....3 as an interpretive type, when holotype, 3. a) Radical leaves present; flowers in neotype or lectotype is ambiguous. racemes; fruits without prickles ...Nicotiana 5.6 Taxonomic Aids b) Radical leaves Taxonomic aids are the tools for the absent; flowers solitary; fruits with prickles .....Datura taxonomic study. Some techniques, procedures and stored information Another type of key for identification that are useful in identification and is the Polyclave or Multi-entry key. It classification of organisms are called consists of a list of numerous character taxonomical aids. They are required states. The user selects all states that in almost all branches of biological match the specimen. Polyclave keys are studies for their proper identification implemented by a computer algorithm. and for finding their relationship with others. Some of the taxonomical aids 2. Flora are keys, flora, revisions, monograph, Flora is the document of all plant species in catalogues, herbarium, botanical a given geographic area. Flora consists of gardens etc. total number of plant species in an area and gives information about flowering season, 1. Keys fruiting season and distribution for the given Taxonomic keys are the tools for the geographic area. It also provides details identification of unfamiliar plants. These on rare and endemic species of that area. keys are based on characters which are Example: ‘Flora of Tamil Nadu’ Carnatic by stable and reliable. The most common type K.M.Matthew. Floras are categorized based of key is a dichotomous key. It consists of a on the scope and area covered. sequence of two contrasting statements. A Local Flora pair of contrasting statements is known as It covers the limited areas, usually couplet. Each statement is known as lead. state, country, city or mountain range. The plant is correctly identified with keys Example: ‘Flora of Thiruvannamalai by narrowing down the characters found District’ by R. Vijaysankar, K. Ravikumar in plant. and P. Ravichandran.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 130 02-06-2018 15:18:56 Regional Flora often confined to diagnostic characters, It includes large geographical area or distribution maps and a classification. a botanical region. Example: ‘Flora of Illustrations mostly in the form of line Tamil Nadu Carnatic’ by K.M.Matthew drawings are included both in monographs (1983), ‘Flora of Madras Presidency’ by and revisions. There are difficulties in J.S. Gamble and Fischer. identifying various members within a taxon. If there is inconsistency of the characters Continental Flora within the taxon’s geographic range then a This flora covers the entire continent. revision is needed. Taxonomic revisions are Example: ‘Flora of Europaea’ by D.A.Web. primarily based on original research work. Example: Malvaceae of India by T.K.Paul, Electronic Floras (e - floras) Venu. P. 2006 Strobilanthes (Acanthaceae) It is nothing but the digitized form of a in Peninsular India. flora published online. Example: ‘e – Flora China’. This provides the information and Catalogues also functions as an identification tool. Catalogues are the books of libraries rich in botanical titles. They have special value 3. Monograph in taxonomic studies. To refer a catalogue, A Monograph is a complete global account one should know full name of the author, of a taxon of any rank – family, genus exact title of the book, exact date of or species at a given time. This includes publication the particulars of edition. the existing taxonomic knowledge and Example: Catalogue of the Library of British all relevant information about the group Museum (of Natural History) Catalogue concerned such as Anatomy, Biochemistry, of the Library of the Massachusetts Palynology, chromosome number and Horticultural Society. phylogeny. It also includes extensive literature review, all nomenclatural 5.7 Botanical Gardens information, identification key to all In true sense all gardens are not botanical taxa, citation of specimens examined and gardens. Botanical gardens are centres distribution map. for collection of plants in their various Example: The Family Lentibulariaceae by stages of living. Gardens existed for Peter Tylor. growing ornamental plants for aesthetic value, religious and status reasons. The Revisions famous “hanging gardens” of Babylon Taxonomic revision is carried out for in Mesopotamia is an example. For the a family or genus. Usually taxonomic purpose of science and education the first revision is less comprehensive than a garden was maintained by Theophrastus monograph for a given geographical area. in his public lecture hall at Athens. Revisions normally incorporate keys First modern botanical garden was to identify the taxa, short descriptions, established by Luca Ghini (1490-1556) a professor of Botany at Pisa, Italy in 1544.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 131 02-06-2018 15:18:56 National Botanical Gardens

National AJCB Indian Botanical garden Botanical garden Lucknow Kolkata

Established in Established in 1948 1786 by Arboretum- Lt. Col. Robert Kyd 500 species of trees

JNTBGRI The National Trivandrum Orchidarium Kerala Yercaud Largest and 500 species Established in Established in oldest of Rose hybrids 1979 1963 Conserving Maintained by 15,000 tropical plant: Southern circle species of Genetic resources of BSI pplants 3,000 trees and 4,000 species 1,800 shrubs plants & Major Attraction- Major attraction- Insectivorous plants germ plasm collection & ex-situ conservationon Major Attraction- 300 species of The Great Banyan Tree plants

Major attraction- Bambusetum (69 species)

Figure 5.1: National Botanical Garden

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 132 02-06-2018 15:18:57 Botanical garden contains special plant collections such as cacti, succulent, green house, shade house, tropical, alpine and exotic plants. Worldwide there are about 1800 botanical gardens and arboreta. Role of Botanical Garden: Botanical Gardens play the following important roles. 1. Gardens with aesthetic value which attract a large number of visitors. For Figure 5.2: Royal Botanic garden, example, the Great Banyan Tree (Ficus Kew - England benghalensis) in the Indian Botanical Garden at Kolkata. Plant collections include Aquatic garden, Arboretum with 14,000 trees, 2. Gardens have a wide range of species Bonsai collection, Cacti collection, and supply taxonomic material for Carnivorous plant collection. botanical research. 3. Garden is used for self-instruction or demonstration purposes. 5.8 Herbarium – Preparation and uses 4. It can integrate information of diverse Herbaria are store houses of preserved fields like Anatomy, Embryology, plant collections. Plants are preserved in Phytochemistry, Cytology, Physiology the form of pressed and dried specimens and Ecology. mounted on a sheet of paper. Herbaria act 5. Act as a conservation centre for diversity, as a centre for research and function as rare and endangered species. sources of material for systematic work. 6. It offers annual list of available species Preparation of herbarium Specimen and a free exchange of seeds. Herbarium Specimen is defined as a 7. Botanical garden gives information pressed and dried plant sample that is about method of propagation, sale of permanently glued or strapped to a sheet plant material to the general public. of paper along with a documentation label. Preparation of herbarium specimen Royal Botanic garden, includes the following steps. Kew- England 1. Plant collection: Field collection, Liquid preserved collection, Living collection, Collection for molecular studies. 2. Documentation of field site data Royal Botanic garden Kew- England 3. Preparation of plant specimen is a non- departmental public body 4. Mounting herbarium specimen in the United Kingdom. It is the largest botanical garden in the world, 5. Herbarium labels. established in 1760, but officially opened 6. Protection of herbarium sheets against in the year 1841. mold and insects

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Plant Collection Plant specimen with fl ower or fruit is collected

Documentation of fi eld site data Certain data are to be recorded at the time of plant collection. It includes date, time, country, state, city, specifi c locality information, latitude, longitude, elevation and land mark information. Th ese data will be typed onto a herbarium label.

Preparation of plant specimen Plant specimen collected from the field is pressed immediately with the help of portable field plant press. plant specimen is transferred to a standard plant press (12” x 18”) which between two outer 12” x 18” frames and secured by two straps.

Mounting herbarium specimen Th e standard size of herbarium sheet is used for mounting the specimen (29cm x 41cm). specimens are affi xed to herbarium sheet with standard white glue or solution of Methyl cellulose.

Herbarium label Herbarium label size is generally 4-5’’ wide and 2-3’’tall. A typical label contains all in- formation like habit, habitat, vegetation type, land mark information, latitude, lon- gitude, image document, collection number, date of collection and name of the collector.

Protection of herbarium sheets against World’s smallest mold and insects Applycation of 2% Mercuric chloride, water – lily Nymphaea Naphthalene, DDT, carbon disulphide. Fu- thermarum was saved migation using formaldehyde. Presently deep from extinction when freezing(-20oC) method is followed through- out the world. it was grown from seed at Kew in 2009.

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Number of S.No Herbarium Year Established Acronym specimens 1. Museum National d’Histoire 1635 P ,PC 10,000,000 Naturelle, Paris, France 2. New York Botanical Garden, 1891 NY 72,00,000 Bronx, New York, U.S.A 3. Komarov Botanical Institute, 1823 LE 71,60,000 St.Petersburg (Leningrad), Russia 4. Royal Botanic Gardens, Kew, 1841 K 70,00,000 England, U.K

National Herbarium Number of S.No Herbarium Year Established Acronym specimens 1. Madras Herbarium 1955 MH 4,08,776 BSI campus, Coimbatore 2. Central National Herbarium 1795 CAL 2,00,000 West Bengal 3. Jawaharlal Nehru Tropical Botanical 1979 TBGT 30,500 Garden and Research Institute Thiruvananthapuram, Kerala 4. Presidency College Herbarium, 1844 PCM 15,000 Chennai.

Uses of Herbarium Kew Herbarium 1. Herbarium provides resource material Kew Garden is situated in South West London for systematic research and studies. that houses the “largest and most diverse 2. It is a place for orderly arrangement of botanical and mycological collections in voucher specimens. the world” founded in the year 1840. Living 3. Voucher specimen serves as a reference collection includes more than 30,000 different for comparing doubtful newly collected kinds of plants. While herbarium which is fresh specimens. one of the largest in the world has over seven 4. Voucher specimens play a role in studies like floristic diversity, environmental million preserved plant specimens. The library assessment, ecological mechanisms contains more than 7,50,000 volumes and the and survey of unexplored areas. illustrations and also a collection of more than 5. Herbarium provides opportunity for 1,75,000 prints, books, photographs, letters, documenting biodiversity and studies manuscripts, periodicals, maps and botanical related to the field of ecology and illustrations. conservation biology.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 135 02-06-2018 15:18:58 5.9 Classification of Plants International Botanic Garden Imagine walking into a library and New York Botanic garden, USA. looking for a Harry Potter story book. Royal Botanic Garden, Kew - England. As you walk into the library you notice Botanical Gardens of the New South that it is under renovation and all the Wales, Sydney. books are scattered. Will it not be hard Rio- de jenerio Botanic Garden, Brazil. to find the exact book you are looking for? It might take hours. So you decide to come the next day when all the books Botanical Survey of India are arranged according to the genres. One rack for adventure, another for Detective, On 13 February 1890, a survey was Fantasy, Horror, Encyclopaedia and so formally constituted and designated on. You automatically know Harry Potter as the Botanical Survey of India. After is in the fantasy section and it takes less independence, the need was felt for a than ten minutes for you to find it. That more comprehensive documentation is because the books have been classified of the country’s plant resources to and arranged according to a system. boost the economy. Padmashree Dr.E.K.Janaki Ammal was appointed Similarly there is a vast assemblage of as officer on special Duty on 14th Oct group of plants in the world. Is it possible 1952. Then reorganization plan was to study and understand all of these? No. finally approved by the Govt. of India Since it is difficult to study all these plants on 29 March 1954, with Calcutta as together, it is necessary to device some the headquarters of BSI. Jammu Tavi means to make this possible. Botanical Garden has been named Classification is essential to biology after Dr. E. K. Janaki Ammal. because there is a vast diversity of organisms to sort out and compare. Unless they are organized into manageable categories it will be difficult for identification. Biological classifications are the inventions of biologists based upon the best evidence available. The scientific basis for cataloguing and retrieving information about the tremendous diversity of flora is Figure 5.3: Dr. E.K. Janaki Ammal known as classification. Classification paves way for the arrangement of organisms into groups Activity on the basis of their similarities, dissimilarities and relationships. The Prepare herbarium of 5 common purpose of classification is to provide a weed plants found inside your school systematic arrangement expressing the campus /nearby garden /waste land. relationship between the organisms.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 136 02-06-2018 15:18:58 Taxonomists have assigned a method described 7,300 species and arranged in of classifying organisms which are called 24 classes mostly on the basis of number, ranks. These taxonomical ranks are union (adhesion and cohesion), length, hierarchical. The scheme of classification and distribution of stamens. The classes has to be flexible, allowing newly were further subdivided on the basis of discovered living organisms to be added carpel characteristics into orders. Hence where they fit best. the system of classification is also known as sexual system of classification. 5.9.1 Need for Classification 24 classes recognized by Linnaeus in • Understanding the classification of his Species Plantarum (1753) on the basis organisms can gives an insight in to of stamens. other fields and has significant practical value. No Classes Characters • Classification helps us to know about 1 Monandria stamen one different taxa, their phylogenetic 2 Diandria stamens two relationship and exact position. 3 Triandria stamens three • It helps to train the students of plant 4 Tetrandria stamens four sciences with regard to the diversity of Pentandria stamens five organisms and their relationship with 5 up to 24th class other biological branches. flowerless plants Cryptogamia

5.10 Types of classification This system of classification though artificial, was continued for more than Taxonomic entities are classified in three 100 years after the death of Linnaeus, ways. They are artificial classification, due to its simplicity and easy way of natural classification and phylogenetic identification of plants. classification. However the system could not hold 5.10.1 Artificial system of classification good due to the following reasons. Carolus Linnaeus 1. Totally unrelated plants were kept in (1707 -1778) was a single group, whereas closely related a great Swedish plants were placed in widely separated Botanist and said groups. Example: to be the “Father of Taxonomy.” a. Zingiberaceae of monocotyledons He outlined an and Anacardiaceae of dicotyledonous artificial system were placed under the class of classification Monandria since these possess in “Species single stamens. Plantarum” in b. Prunus was classified along with 1753, wherein Figure 5.4: Cactus because of the same number he listed and Carolus Linnaeus of stamens.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 137 02-06-2018 15:18:59 No attempts were made to classify Class I Dicotyledonae: Plants contain plants based on either natural or two cotyledons in their seed, leaves with phylogenetic relationships which exist reticulate venation, tap root system and among plant groups. tetramerous or pentamerous flowers come 5.10.2 Natural system under this class. It includes three sub- classes – Polypetalae, Gamopetalae and Botanists who came after Linnaeus realised Monochlamydeae. that no single character is more important than the other characters. Accordingly Sub-class 1. Polypetalae: Plants with an approach to a natural system of free petals and dichlamydeous flowers classification sprouted in France. The first come under polypetalae. It is further scheme of classification based on overall divided into three series – Thalamiflorae, similarities was presented by Antoine Disciflorae and Calyciflorae. Laurent de Jessieu in 1789. Series (i) Thalamiflorae: Plants Bentham and Hooker system of having flowers with dome or conical classification shaped thalamus and superior ovary are included in this series. It includes 6 orders and 34 families. Series (ii) Disciflorae: Flowers having prominent disc shaped thalamus with superior ovary come under this series. It includes 4 orders and 23 families. Series (iii) Calyciflorae: It includes plants having flowers with cup shaped thalamus Figure 5.5: George Bentham and and with inferior or sometimes with half J.D. Hooker. inferior ovary. Calyciflorae includes 5 orders and 27 families. A widely followed natural system of classification considered the best was Sub-class 2. Gamopetalae: Plants with proposed by two English botanist united petals, which are either partially George Bentham (1800 - 1884) and or completely fused to one another Joseph Dalton Hooker (1817–1911). The and dichlamydeous are placed under classification was published in a three Gamopetalae. It is further divided into volume work as “Genera Plantarum” three series – Inferae, Heteromerae and (1862–1883) describing 202 families Bicarpellatae. and 7569 genera and 97, 205 species. In this system the seeded plants were Series (i) Inferae: The flowers are classified into 3 major classes such as epigynous and with inferior ovary. Inferae Dicotyledonae, Gymnospermae and includes 3 orders and 9 families. Monocotyledonae.

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Class I Class II Class III Dicotyledonae Gymnospermae Monocotyledonae 3 families 7series and 34 families 1. Gnetaceae 2. Coniferae 3. Cycadaceae

Sub-classI Sub-class II Sub-class III Polypetalae Gamopetalae Monochlamydeae 8 series and 36 families Series (i) Thalamiflorae Series (i) Inferae 6 orders and 34 families 3 orders and 9 families

Series (ii) Disciflorae Series (ii) Heteromerae 4orders and 23 families 3 orders and 12 families

Series (iii) Calyciiflorae Series (iii) Bicarpellatae 5orders and 27 families 4 orders and 24 families

Figure 5.6: Bentham and Hooker system of classification

Series (ii) Heteromerae: The flowers Gymnospermae includes three families – are hypogynous, superior ovary and with Gnetaceae, Coniferae and Cycadaceae. more than two carpels. Heteromerae Class III Monocotyledonae: Plants includes 3 orders and 12 families. contain only one cotyledon in their seed, Series (iii) Bicarpellatae: The flowers leaves with parallel venation, fibrous root are hypogynous, superior ovary and with system and trimerous flowers come under two carpels.Bicarpellatae includes 4 orders this class. The Monocotyledonae has 7 series and 34 families. and 24 families. The Bentham and Hooker system of Sub-class 3. Monochlamydeae: Plants classification is still supposed to be the best with incomplete flowers either apetalous system of classification. It has been widely or with undifferenciated calyx and corolla practiced in colonial countries and herbaria are placed under Monochlamydeae. The of those countries were organised based on sepals and petals are not distinguished and this system and is still used as a key for the they are called perianth. Sometimes both identification of plants in some herbaria of the whorls are absent. Monochlamydeae the world due to the following reasons: includes 8 series and 36 families. • Description of plants is quite accurate Class II Gymnospermae: Plants that and reliable, because it is mainly based on contain naked seeds come under this class. personal studies from actual specimens

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 139 02-06-2018 15:18:59 and not mere comparisons of known facts. • As it is easy to follow, it is used as a key for the identification of plants in several herbaria of the world. Though it is a natural system, this system was not intended to be phylogenetic.

5.10.3 Phylogenetic system of Figure 5.7: Adolph Engler and Karl A classification Prantl The publication of the Origin of Species first 11 divisions are Thallophytes, twelfth (1859) by Charles Darwin has given division is Embryophyta Asiphonogama stimulus for the emergence of phylogenetic (plants with embryos but no pollen tubes; system of classification. Bryophytes and Pteridophytes) and the I Adolph Engler and Karl A Prantl thirteenth division is Embryophyta system of classification Siphonogama (plants with embryos and One of the earliest phylogenetic system of pollen tubes) which includes seed plants. classification of the entire plant Kingdom II Arthur Cronquist system of was jointly proposed by two German classification botanists Adolph Engler ( 1844 -1930) and Arthur Cronquist (1919 - 1992) an eminent Karl A Prantl (1849 - 1893). They published American taxonomist proposed their classification in a monumental work phylogenetic classification of flowering “Die Naturelichen Pflanzen Familien” in plants based on a wide range of taxonomic 23 volumes (1887- 1915) characters including anatomical and In this system of classification the plant phytochemical characters of phylogenetic kingdom was divided into 13 divisions. The importance. He has presented his

Division: Embryophyta (Siphonogama)

Sub-division:Gymnospermae Sub-division: Angiospermae

Class: Monocotyledonae Class: Dicotyledonae (includes 11 orders 45 families) (includes 44 orders)

Archichlamydeae Metachlamydeae (Apetalae) (Sympetalae) (i) Corolla polypetalous (i) Corolla Gamopetalous (ii) Perianth single or double (ii) Perianth in two whorls (iii) Includes 33 orders 201 families (iii) Includes 11 orders 57 families Figure 5.8: Outline of Engler and Prantl classification

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 140 02-06-2018 15:18:59 classification in 1968 in his book titled Cronquist classified the angiosperms “The evolution and classification of into two main classes Magnoliopsida flowering plants.” His classification (=dicotyledons) and Liliopsida is broadly based on the Principles of (= monocotyledons). There are phylogeny that finds acceptance with 6 subclasses, 64 orders, 320 families and major contemporary authors. about 165,000 species in Magnoliopsida, whereas in Liliopsida there are 5 sub classes, 19 orders, 66 families and about 50,000 species. Cronquist system of classification also could not persist for a long time because, the system is not very useful for identification and cannot be adopted in herbaria due to its high phylogenetic Figure 5.9: Arthur Cronquist nature.

Rosidae (5) )

Asteridae (6 4. Zingiberidae

3. Commelinidae 5. Lilidae Dilleniidae (4) Hamamelidae (2) s

Magnoliidae Caryophyllidae (3) 2. Arecidae (1) Sub-clas

1. Alismatidae Sub-class

Class: Magnoliopsida Class: Liliopsida

Figure 5.10: Diagramatic representation of the relationship between class Magnoliopsida and Liliopsida.

5.10.4 Angiosperm phylogeny group classification (APG I, APG II, APG III (APG) classification & APG IV) have been published in 1998, The most recent classification of 2003, 2009 and 2016 respectively. Each flowering plants based on phylogenetic version supplants the previous version. data was set in the last decade of Recognition of monophyletic group twentieth century. Four versions based on the information received of Angiosperm Phylogenetic group from various disciplines such as gross

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 141 02-06-2018 15:19:00 Morphology, Anatomy, Embryology, 26 families (ANA-grade + magnoliids Palynology, Karyology, Phytochemistry + Chloranthales) and more strongly on molecular data Amborellales with respect to DNA sequences of two Nymphaeales chloroplast genes (atpB and rbcL) and Austrobaileyales one nuclear gene (nuclear ribosomal ➢ Seeds always with two cotyledons. 18s DNA). ➢ Presence of ethereal oils. The most recent updated version, APG IV (2016) recognised 64 orders and ➢ Leaves are always simple net-veined. 416families. Of these, 416 families 259 are ➢ Each floral whorls with many parts. represented in India. ➢ Perianth usually spirally arranged The outline of APG IV classification is or parts in threes. given below. ➢ Stamens with broad filaments. ➢ Anthers tetrasporangiate.

Amborellales ➢ Pollen monosulcate. Nymphaeales ➢ Nectaries are rare. Austrobaileyales

EARLY Magnoliids ➢ Carpels usually free and.

ANGIOSPERMS Chloranthales ➢ Embryo very small. MONOCOTS Monocots Family: Liliaceae Monocots are classified into 11 orders Ceratophyllales and 77 families (basal monocots + lilioids Ranunculales Proteales + commelinids)

EUDICOTS Torchodendrales

Early Buxales ➢ Seeds with single cotyledon. eudicots diverging Gunnerales Dilleniales ➢ Primary root short-lived. Saxifragales ➢ Single adaxial prophyll. Rosids Super rosids Family: Fabaceae ➢ Ethereal oils rarely present. Berberidopsidales Santalales ➢ Mostly herbaceous, absence of

Super Caryophyllales vascular cambium. asterids Asterids Family: Solanaceae ➢ Vascular bundles are scattered in Figure 5.11: Simplified version of APG IV the stem. ( Source: Plant Gateway's The Global Flora, ➢ Leaf simple with parallel-veined. Vol. I January 2018 ) ➢ Floral parts usually in threes. ➢ Perianth often composed of tepals. Angiosperms are classified into three ➢ Pollen monosulcate. clades early angiosperms, monocots and eudicots. Early angiosperms ➢ Styles normally hollow and. are classified into 8 orders and ➢ Successive microsporogenesis.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 142 02-06-2018 15:19:00 Eudicots are divided into 45 orders into the Indian botanical curriculum. and 313 families (early diverging eudicots Classification reflects the state of our + super rosids + super asterids). knowledge at a given point of time. It will ➢ Seeds with always two cotyledons. continue to change as we acquire new ➢ Nodes trilacunar with three leaf traces. information. ➢ Stomata anomocytic. ➢ Ethereal oils rarely present. A significant number ➢ Woody or herbaceous plants. of major herbaria, including Kew are ➢ Leaves simple or compound, changing the order usually net-veined. of their collections in ➢ Flower parts mostly in twos, fours accordance with APG. or fives. The influential world checklist of ➢ Microsporogenesis simultaneous. selected plant families (also from kew) is being updated to the APG III system. ➢ Style solid and . A recent photographic survey ➢ Pollen tricolpate. of the plants of USA and Canada is APG system is an evolving system that organized according to the APG III might undergo change periodically based on system. the new sets of data from various disciplines In UK, the latest edition of the of Botany. It is the currently accepted system standard flora of the British Isles across the world and followed by all the written by Stace is based on the APG leading taxonomic institutions and practising III system. taxonomists. However, it is yet to percolate Families 202 303 386462 457413 416

Bentham and Engler and Arthur Cronquist APG I APG II APG III APG IV Hooker 1883 Prantl1915 1981 1998 2003 2009 2016 Figure 5.12: A timeline showing the history of classifying flowering plants into families. ( Source: Royal Botanic Gardens Kew State of World's Plant 2017 )

5.11 Modern trends in taxonomy Palynology, Phenology, Bio-chemistry, Taxonomists now accept that, the Numerical taxonomy and transplant morphological characters alone should not experiments. These have been found to be be considered in systematic classification useful in solving some of the taxonomical of plants. The complete knowledge of problems by providing additional taxonomy is possible with the principles of characters. It has changed the face of various disciplines like Cytology, Genetics, classification from alpha (classical) to omega Anatomy, Physiology, Geographical (modern kind). Thus the new systematic has distribution, Embryology, Ecology, evolved into a better taxonomy.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 143 02-06-2018 15:19:00 5.11.1 Chemotaxonomy Aims of biosystematics Various medicines, spices and preservatives The aims of biosystematics are as follows: obtained from plant have drawn the 1. To delimit the naturally occurring attention of Taxonomists. Study of biotic community of plant species. various chemicals available in plants help 2. To establish the evolution of a to solve certain taxonomical problems. group of taxa by understanding Chemotaxonomy is the scientific approach the evolutionary and phylogenetic of classification of plants on the basis of their trends. biochemical constituents. As proteins are 3. To involve any type of data gathering more closely controlled by genes and less based on modern concepts and not subjected to natural selection, it has been only on morphology and anatomy. used at all hierarchical levels of classification starting from the rank of ‘variety’ up to the 4. To recognize the various groups as rank of division in plants. Proteins, amino separate biosystematic categories acids, nucleic acids, peptides etc. are the most such as ecotypes, ecospecies, studied chemicals in chemotaxonomy. cenospecies and comparium. The chemical characters can be divided 5.11.3 Karyotaxonomy into three main categories. Chromosomes are the carriers of genetic 1. Easily visible characters like starch information. Increased knowledge about grains, silica etc. the chromosomes have been used for 2. Characters detected by chemical tests extensive biosystematic studies and like phenolics, oil, fats, waxes etc. resolving many taxonomic problems. 3. Proteins Utilization of the characters and Aims of chemotaxonomy phenomena of cytology for the explanation of taxonomic problem is known as 1. To develop taxonomic characters cytotaxonomy or karyotaxonomy. The which may improve existing system characters of chromosome such as number, of plant classification. size, morphology and behaviour during 2. To improve present day knowledge meiosis have proved to be of taxonomic of phylogeny of plants. value.

5.11.2 Biosystematics 5.11.4 Serotaxonomy (immunotaxonomy) Biosystematics is an “Experimental, Systematic serology or serotaxonomy had ecological and cytotaxonomy” through its origin towards the end of twentieth which life forms are studied and their century with the discovery of serological relationships are defined. The term reactions and development of the discipline biosystematics was introduced by Camp of immunology. The classification of very and Gilly in 1943. Many authors feel similar plants by means of differences in the Biosystematics is closer to Cytogenetics proteins they contain, to solve taxonomic and Ecology and much importance given problems is called serotaxonomy. not to classification but to evolution.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 144 02-06-2018 15:19:00 Smith (1976) defined it as “the study of Uses of molecular taxonomy the origins and properties of antisera.” 1. Molecular taxonomy helps in establishing the relationship of Importance of serotaxonomy different plant groups at DNA level. It determines the degree of similarity 2. It unlocks the treasure chest of between species, genera, families etc. by information on evolutionary history of comparing the reactions of antigens from various plant taxa with antibodies raised organisms. against the antigen of a given taxon. RFLP (Restriction Fragment Length Example: 1. The assignment of Polymorphism) Phaseolus aureus and P. mungo to the genus RFLPs is a molecular method of genetic Vigna is strongly supported by serological analysis that allows identification of taxa evidence by Chrispeels and Gartner. based on unique patterns of restriction sites in specific regions of DNA. It refers 5.11.5 Molecular taxonomy (molecular to differences between taxa in restriction systematics / molecular phylogenetics) sites and therefore the lengths of fragments Molecular Taxonomy is the branch of DNA following cleavage with restriction of phylogeny that analyses hereditary enzymes. molecular differences, mainly in DNA Amplified Fragment Length sequences, to gain information and to Polymorphism (AFLP) establish genetic relationship between the This method is similar to that of members of different taxonomic categories. identifying RFLPs in that a restriction The advent of DNA cloning and sequencing enzyme is used to cut DNA into numerous methods have contributed immensely to the smaller pieces, each of which terminates development of molecular taxonomy and in a characteristic nucleotide sequence population genetics over the years. These due to the action of restriction enzymes. modern methods have revolutionised the AFLP is largely used for population field of molecular taxonomy and population genetics studies, but has been used in genetics with improved analytical power studies of closely related species and even and precision. in some cases, for higher level cladistic The results of a molecular analysis. phylogenetic analysis are expressed in the form of a tree called phylogenetic Random Amplified Polymorphic DNA tree. Different molecular markers (RAPD) like allozymes, mitochondrial DNA, It is a method to identify genetic markers micro satellites, RFLP (Restriction using a randomly synthesized primer Fragment Length Polymorphism), RAPD that will anneal (recombine (DNA) in the (Random amplified polymorphic DNA), double stranded form) to complementary AFLPs (Amplified Fragment Length regions located in various locations of Polymorphism), single nucleotide isolated DNA. If another complementary polymorphism- SNP, microchips or arrays site is present on the opposing DNA are used in analysis. strand at a distance that is not too great

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 145 02-06-2018 15:19:00 (within the limits of PCR) then the in two genes of the chloroplast, matK reaction will amplify this region of DNA. and rbcL, and have been approved as the RAPDs like microsatellites may often barcode regions for plants. be used for genetic studies within species Sequence of unknown species can be but may also be successfully employed matched from submitted sequence in in phylogenetic studies to address GenBank using Blast (web-programme for relationships within a species or between searching the closely related sequence). closely related species. However RAPD Significance of DNA barcoding analysis has the major disadvantage that results are difficult to replicate and in that 1. DNA barcoding greatly helps in the homology of similar bands in different identification and classification of taxa may be nuclear. organism. 2. It aids in mapping the extent of Significance of Molecular Taxonomy biodiversity. 1. It helps to identify a very large number DNA barcoding techniques require a of species of plants and animals by the large database of sequences for comparison use of conserved molecular sequences. and prior knowledge of the barcoding region. 2. Using DNA data evolutionary patterns However, DNA barcoding is a helpful of biodiversity are now investigated. tool to determine the authenticity of 3. DNA taxonomy plays a vital role in botanical material in whole, cut or phytogeography, which ultimately powdered form. helps in genome mapping and biodiversity conservation. 5.11.7 Differences between classical and 4. DNA- based molecular markers used modern taxonomy for designing DNA based molecular Classical Taxonomy Modern Taxonomy probes, have also been developed under It is called old It is called the branch of molecular systematics. systematics or Alpha Neosystematics or (ἀ) taxonomy or Biosystematics or 5.11.6 DNA Barcoding Taxonomy Omega (Ω) taxonomy Have you seen how scanners are used in It is pre Darwinean It is post ­Darwinean supermarkets to distinguish the Universal Species is considered species is considered Product Code (UPC)? In the same way we as basic unit and is as dynamic entity and static ever changing can also distinguish one species from another. Classification is Classification is DNA barcoding is a taxonomic method that mainly based on based on morpho- uses a very short genetic sequence from morphological logical, reproduc- a standard part of a genome. The genetic characters tive characters and sequence used to identify a plant is known phylogenetic (evolu- as “DNA tags” or “DNA barcodes”. Paul tionary) relationship Hebert in 2003 proposed ‘DNA barcoding’ of the organism This system is based This system is based and he is considered as ‘Father of barcoding’. on the observation of on the observation of The gene region that is being used as a few samples/ large number of sam- an effective barcode in plants is present individuals ples/individuals

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 146 02-06-2018 15:19:00 5.12 Cladistics seed and so on; behavioural, like opening of Analysis of the taxonomic flowers nocturnal/diurnal; molecular like, data, and the types of DNA or protein sequence and more. characters that are used Cladistics accept only monophyletic in classification have groups. Paraphyletic and polyphyletic changed from time to taxa are occasionally considered when time. Plants have been classified based on such taxa conveniently treated as one the morphology before the advancement of group for practical purposes. Example: microscopes, which help in the inclusions dicots, sterculiaceae. Polyphyletic groups of sub microscopic and microscopic are rejected by cladistics. features. A closer study is necessary i. Monophyletic group; Taxa while classifying closely related plants. comprising all the descendants of a Discovery of new finer molecular analytical common ancestor. techniques coupled with advanced software C A D B and computers has ushered in a new era of modern or phylogenetic classification. The method of classifying organisms into monophyletic group of a common ancestor based on shared apomorphic characters is called cladistics (from Greek, klados- ii. Paraphyletic group; Taxon that branch). includes an ancestor but not all of the The outcome of a cladistic analysis is descendants of that ancestor. a cladogram, a tree-shaped diagram that A C B D represent the best hypothesis of phylogenetic relationships. Earlier generated cladograms CB, CBD were largely on the basis of morphological and ACB are characters, but now genetic sequencing data paraphyletic and computational softwares are commonly group used in phylogenetic analysis. iii. Polyphyletic group; Taxa that Cladistic analysis includes members from two different lineages. Cladistics is one of the primary methods of constructing phylogenies, or evolutionary C A D B W X Z Y histories. Cladistics uses shared, derived characters to group organisms into clades. These clades have atleast one shared, derived character found in their most recent common ancestor that is not found in other groups Need for cladistics hence they are considered more closely related 1. Cladistics is now the most commonly to each other. These shared characters can used and accepted method for creating be morphological such as, leaf, flower, fruit, phylogenetic system of classifications.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 147 02-06-2018 15:19:00 2. Cladistics produces a hypothesis about Phylogenetic and APG system in the relationship of organisms to predict course of time. Bentham and Hooker the morphological characteristics of system of classification is followed organism. in India till recently. Great variation 3. Cladistics helps to elucidate mechanism occurs not only in different families, of evolution. but also varies in genera and species which are included within the 5.13 Selected Families of Angiosperms family. Variation occurs in number, Dicot Families arrangement, adhesion and cohesion of the floral parts. We study a few Plant kingdom is so vast and varied. families for understanding the process For the purpose of study, they have and purpose of classification. been classified into Artificial, Natural,

5.13.1 Family: Fabaceae (Pea family) Systematic position Bentham and Hooker APG classification classification Kingdom: Plantae Kingdom: Plantae Clade Angiosperms Class: Dicotyledonae Clade Eudicots Sub-class: Polypetalae Clade Rosids Series: Calyciflorae Order: Fabales Order: Rosales Family: Fabaceae Family: Fabaceae

Diagnostic features General characters • Leaves simple or imparipinnately Distribution: Fabaceae includes about 741 compound or palmate, leaf base genera and more than 20,200 species. The pulvinate, leaflets stipellate. members are cosmopolitan in distribution but abundant in tropical and subtropical • Flowers Zygomorphic regions. • Corolla: Papilionaceous, descendingly Habit: All types of habits are imbricate aestivation, posterior petal represented in this family. Mostly outermost, herbs (Indigofera, Crotalaria), prostrate • Petals clawed. (Indigofera enneaphylla) erect (Crotalaria • Stamens : Monadelphous, diadelphous verrucosa), shrubs (Cajanus cajan), small trees (Sesbania), climbers (Clitoria), large • Ovary stipitate (a short stalk as the tree (Pongamia, Dalbergia, Erythrina, base), monocarpellary, unilocular with Butea), woody climber (Mucuna), marginal placentation. hydrophyte (Aeschynomene aspera) • Fruit a legume or lomentum. commonly called pith plant.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 148 02-06-2018 15:19:01 Root: Tap are partly fused and are called keel root system, petals or carina which encloses the roots are stamens and pistil. nodulated, Androecium: Stamens 10, have tubercles diadelphous, usually 9+1 (Clitoria containing ternatea). The odd stamen is posterior nitrogen – fixing Root nodule in position. In Aeschynomene aspera, the bacteria (Rhizobium leguminosarum) stamens are fused to form two bundles each Stem: Aerial, herbaceous, woody containing five stamens (5)+5. Stamens (Dalbergia) twining or climbing Clitoria. are monadelphous and dimorphic Leaf: Leaf simple or unifoliate ie. 5 stamens have longer filaments and (Desmodium gangeticum) bifoliate (Zornia other 5 stamens have shorter filaments diphylla,), Trifoliate (Lablab purpureus), thus the stamens are found at two levels unipinnate or simple pinnate (Clitoria), and the shape of anthers also varies alternate, stipulate, leaf base, pulvinate, in (Crotalaria verrucosa). (5 anthers stipulus 2, free. Leaves showing reticulate are long and lanceolate, and the other venation terminal leaflet modifies into a 5 anthers are short and blunt). Anthers tendril in Pisum sativum. are dithecous, basifixed and dehiscing Inflorescence: Raceme (Crotalaria longitudinally. verrucosa), panicle (Dalbergia latifolia) Gynoecium: Monocarpellary, axillary solitary (Clitoria ternatea) unilocular, ovary superior, with two Flowers: Bracteate, bracteolate alternating rows of ovules on marginal (Sesbania), pedicellate, complete, bisexual, placentation. Style simple and bent, stigma pentamerous, heterochlamydeous, flattened or feathery. zygomorphic hypogynous or sometimes Fruit: The characteristic fruit of perigynous. Fabaceae is a legume (Pisum sativum), Calyx: Sepals 5, green, synsepalous, sometimes indehiscent and rarely a more or less united in a tube and persistant, lomentum (Desmodium). valvate or imbricate, odd sepal is anterior In Arachis hypogea the fruit is in position. geocarpic (fruits develops and matures from underground). After fertilization Corolla: Petals 5, apopetalous, the stipe of the ovary becomes unequal and papilionaceous, vexillary meristematic and grows down into the or descendingly imbricate aestivation soil. This ovary gets buried into the soil all petals have claw at the base. The and develops into fruit. outer most petal is large called standard Seed: Endospermic or non- petal or vexillum, Lateral 2 petals are endospermic (Pisum sativum), mostly lanceolate and curved. They are called reniformed. wing petals or alae. Anterior two petals

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 149 02-06-2018 15:19:01 Botanical description of Clitoria ternatea (Sangu pushpam)

Standard petal Stigma Stamen Style Ovary Calyx Stipe

L.S of flower

Anther Filament

Habit Single stamen Sepal Standard petal

Androecium

Wing petal Calyx

Keel petal Stigma Corolla Style

Ovule Ovary Locule Stipe Gynoecium C.S.of Ovary

Floral formula

Br.,Brl.,%, , K(5),C5,A(9)+1,G1 Floral diagram Figure 5.13: Clitoria ternatea

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 150 02-06-2018 15:19:02 Habit: Twining climber Corolla: Petals 5, white or blue Root: Branched tap root system having apopetalous, irregular papilionaceous nodules. corolla showing, descendingly imbricate Stem: Aerial, weak stem and a twiner aestivation. Leaf: Imparipinnately compound, Androecium: Stamens 10, diadelphous alternate, stipulate showing reticulate (9)+1 nine stamens fused to form a bundle venation. Leaflets are stipellate. Petiolate and the tenth stamen is free. Anthers and stipels are pulvinated. are dithecous, basifixed, introse and dechiscing by longitudinal slits. Inflorescence: Solitary and axillary Gynoecium: Monocarpellary, uni- Flower: Bracteate, bracteolate, bracteoles locular, with many ovules on mariginal usually large, pedicellate, ­heterochlamydeous, ­placentation, ovary superior, style simple complete, bisexual, pentamerous, zygomor- and incurved with feathery stigma. phic and hypogynous. Fruit: Legume Calyx: Sepals 5, synsepalous, green showing valvate aestivation. Odd sepal is Seed: Non-endospermous, reniform. Dt0.Dtn0.'.""."M .E .C .I anterior in position. Floral Formula: *7+ 7 *;+-3 3

Tendril

Standard petal Flower Stigma Stamen Style

Ovary

Calyx Stipe Jcdkv N0U0qh"hnqygt"

Standard Anther petal Filament Sepal Wing petal Single stamen

Keel patal

Ecn{z" Eqtqnnc" Cpftqgekwo

Stigma

Style

Ovary Ovule Stipe Locule I{pqgekwo E0U0qh"Qxct{

Hnqtcn"hqtownc Dt0.Dtn0.'.""."M .E .C .I *7+ 7 *;+-3 3 Hnqtcn"fkcitco

Figure 5.14: Pisum sativum

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 151 02-06-2018 15:19:02 Economic Importance of the family Fabaceae

Economic Binomial Useful Uses importance part Pulses Cajanus cajan Seeds Sources of protein and starch of our food. (Pigeon Pea) Phaseolus vulgaris (French bean) Cicer arietinum (Chick pea / Channa / க�ொண்翈க்கடை) Vigna mungo (black gram / உ쿁ꏍ鏁) Vigna radiata (green gram / பா殿ப்ய쟁) Vigna unguiculata (cow pea / தட்翈ப்ய쟁) Glycine max (soya bean) Macrotyloma uniflorum (Horse gram / க�ொ쿍쿁) Food plants Lablab purpureus Tender Vegetable (field bean) fruits Sesbania grandiflora (agathi, Leaves Greens vegetable humming bird) Cyamopsis tetragonoloba Tender Vegetable (cluster bean) fruits Oil Plants Arachis hypogea (Ground nut) Seeds Oil extracted from the seeds is edible and used for cooking. Pongamia pinnata (Pungam) Seeds Pongam oil has medicinal value and is used in the preparation of soap. Timber Dalbergia latifolia Timber Timber is used for making furniture, cab- Plants (rose wood) inet articles and as building materials. Pterocarpus santalinus (red sandalwood) P.dalbergioides (Padauk) P.marsupium (வேங்க) Medicinal Crotalaria albida Roots Used as purgative Plants Psoralea corylifolia Seeds used in leprosy and leucoderma (கார்போக அ쎿殿) Glycirrhiza glabra Roots Immuno modulater (Licorice root / அ鎿ம鏁ர믍) Mucuna pruriens Seeds Neurological remedy (ꯂனைக்க쮿) Fibre Plants Crotalaria juncea Stem Used for making ropes. (sunhemp / சணப்ப) fibres Sesbania sesban (aegyptiaca) (Bast)

Continued 152

TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 152 02-06-2018 15:19:03 Economic Binomial Useful Uses importance part Pith Plant Aeschynomene aspera Stem Used for packing, handicraft and fishing pith floats Dye Indigofera tinctoria (Avuri) Leaves Indigo dye obtained from leaves is used Plants to colour printing and in paints. Blue dye is obtained Clitoria ternatea Flowers and seeds Natural dye Butea monosperma Flowers Green Indigofera tinctoria Entire Used as green manure because of the Manuring Tephrosea purpurea plant presence of nitrogen fixing bacteria in Gliricidia sepium the lateral roots.

Ornamental Butea frondosa Entire Grown as ornamental plants. Plants (Flame of the forest), plant Clitoria ternatea, Lathyrus odoratus (Sweet pea) and Lupinus hirsutus (Lupin)

Diabetes Remedy

The aerial parts ofGalega officinalis The seeds of Abrus precatorius are (Fabaceae) contains Metformin (dimeth- used in necklaces and rosaries, but are yl biguanide). It is now reputed to be the extremely poisonous and can be fatal if most widely prescribed agent in the treat- ingested. ment of diabetes all over the world.

INTERNATIONAL YEAR OF PULSES

The Food and Agriculture Organization The attractive seeds of Adenanthera (FAO) of the United Nations has been pavonina (Family: Caesalpineacece) nominated to declare 2016 as the year have been used as units of weight for for pulses, to make people more aware the measures of gold throughout India. of the nutritional value of pulses,

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 153 02-06-2018 15:19:04 Arachis hypogea Crotalaria verrucosa Indigofera tinctoria Aeschynomene aspera Figure 5.15: Selected plants belongs to the Family Fabaceae 5.13.2 Family: Solanaceae (Potato Family / Night shade family) Systematic Position Bentham and Hooker system APG system of classification of classification Kingdom: Plantae Kingdom: Plantae Clade : Angiosperms Class: Dicotyledonae Clade: Eudicot Subclass: Gamopetalae Clade: Asterids Series: Bicarpellatae Clade: Solanales Order: Polemoniales Family: Solanaceae Family: Solanaceae

Diagnostic Features family with about 1500 species. Plants • Leaves alternate, exstipulate are worldwide in distribution but more • Flowers actinomorphic, pentamerous abundant in South America. • Calyx often persistence / accrescent Habit: Mostly annual herbs, shrubs, small trees (Solanum violaceum) lianas • Stamens 5, epipetalous, poricidal in with prickles (Solanum trilobatum) many dehiscence with stellate trichomes; rarely vines • Carpels 2, ovary superior, 2 chambered, (Lycium sinensis) obliquely placed, falsely four chambered Root: Branched tap root system. placenta swollen, ovule numerous. Stem: Herbaceous or woody; erect or • Fruits berry or capsule, vascular twining, or creeping; sometimes modified bundles with both outer and inner into tubers (Solanum tuberosum) often phloem (Bicollateral vascular bundle) with bicollateral vascular bundles. General Characters Leaves: Alternate, simple, rarely Distribution: pinnately compound(Solanum tuberosum Family Solanaceae includes about 88 and (Lycopersicon esculentum) exstipulate, genera and about 2650 species, of these opposite or sub-opposite in upper part, Solanum is the largest genus of the unicostate reticulate venation.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 154 02-06-2018 15:19:07 Inflorescence: Generally axillary or Botanical description of Datura metel terminal cymose (Solanum) or solitary Habit: Large, erect and stout herb. flowers (Datura stramonium). Extra Root: Branched tap root system. axillary scorpiod cyme called rhiphidium Stem: Stem is hollow, green and (Solanum nigrum) solitary and axillary herbaceous with strong odour. (Datura and Nicotiana) umbellate cyme (Withania somnifera). Leaf: Simple, alternate, petiolate, entire or deeply lobed, glabrous exstipulate Flowers: Bracteate (Petunia), or showing unicostate reticulate venation. ebracteate (Withania) pedicellate, Inflorescence: Solitary and axillary bisexual, heterochlamydeous, cyme. actinomorphic or weakly zygomorphic due to oblique position of ovary pentamerous, Flower: Flowers are large, greenish white, hypogynous. bracteate, ebracteolate, pedicellate, complete, heterochlamydeous, pentamerous, regular, Calyx: Sepals 5, rarely 4 or 6, Synsepalous, actinomorphic, bisexual and hypogynous. valvale peristaent, often accrescent Calyx: Sepals 5, green synsepalous (enlarging to envelop the fruit) occasionally showing valvate aestivation. Calyx is enclosing the fruit ( Physalis, Withania) mostly persistant, odd sepal is posterior Corolla: Petals 5, sympetalous, in position. rotate, tubular (Solanum) or bell- shaped Corolla: petals 5, greenish white, (Atropa) or infundibuliform (Petunia) sympetalous, plicate (folded like a fan) usually alternate with sepals; rarely showing twisted aestivation, funnel bilipped and zygomorphic (Schizanthus) shaped with wide mouth and 10 lobed. usually valvate, sometimes convolute Androecium: Stamens 5, free from (Datura). one another, epipetalous, alternipetalous Androecium: Stamens 5, epipetalous, and are inserted in the middle of the filaments usually unequal in length, corolla tube. Anthers are basifixed, stamens only 2 in Schizanthus, 4 and dithecous, with long filament, introse and didynamous in (Salpiglossis) Anthers longitudinally dehiscent. dithecous, dehisce longitudinally or Gynoecium: Ovary bicarpellary, poricidal. syncarpous superior. Basically biloculear Gynoecium: Bicarpellary, syncarpous but tetralocular due to the formation of obliquely placed, ovary superior, bilocular false septum. Carpels are obliquely placed but looks tetralocular due to the formation and ovules on swollen axile placentation. of false septa, numerous ovules in each Style simple long and filiform, stigma two locule on axile placentation. lobed. Fruit: A capsule or berry. In Fruit: Spinescent capsule opening by Lycopersicon esculentum, Capsicum, the four apical valves with persistent calyx. fruit is a berry and in species of Datura Seed: Endospermous.

and Petunia, the fruit is a capsule. Floral Formula: Dt0.Gdtn0.""".""".M*7+.E*7+.C7.I*4+ Seed: Endospermous.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 155 02-06-2018 15:19:07 Leaf Stamen Corolla Stamen Corolla Calyx Calyx

Habit Flower entire

Corolla Stigma

Sepal Anther Style Ovule Swollen Epipetalous placenta stamens Ovary C.S. of Ovary

Calyx Corolla cut open Gynoecium

Valve Spiny Seed outgrowth Spiny Persistent outgrowth calyx Persistent calyx Fruit: Spinescent Fruit - After capsule dehiscence

Floral formula Floral Diagram Br.,Ebrl., , ,K(5),C(5),A5,G(2) Figure 5.16: Datura metel

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 156 02-06-2018 15:19:08 Economic importance Economic importance of the family solanaceae S.No Economic Binomial Useful part Uses importance 1. Food plant Solanum tuberosum Underground Used as vegetables and also (potato) stem tubers used for the production of starch. Lycopersicon esculentum Ripened fruits Used as delicious vegetable (tomato) and eaten raw. Solanum melongena Tender fruits Cooked and eaten as (brinjal) vegetable. Capsicum annuum (bell Fruits Used as vegetables and peppers & chilli papers) powdered chilli is the dried C. frutescens (뮿ளகா뿍) pulverized fruit which is used as spice to add pungency or piquancy and flavour to dishes . Physalis peruviana (cape Fruit Used as delicious fruit. gooseberry / ச�ொடக埁 தக்க쾿) 2. Medicinal Atropa belladonna Roots A powerful alkaloid plant (deadly nightshade) ‘atropine’ obtained from root is used in belladona plasters, tinctures etc. for relieving pain and also for dialating pupils of eyes for eye –testing. Datura stramonium Leaves and Stramonium drug obtained (ஊமத்த) roots from the leaves and roots of this is used to treat asthma and whooping cough. Solanum trilobatum Leaves, flowers Used to treat cough. (鏂鏁வளை) and berries Withania somnifera Roots Used in curing cough and (Ashwagandha / rheumatism. அ믁க்கரா) Continued

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 157 02-06-2018 15:19:08 Economic importance of the family solanaceae S.No Economic Binomial Useful part Uses importance 3. Tobacco Nicotiana tabaccum Leaves are Used in cigarette, beedi, (tobacco / ꯁகை뾿லை) dried and hukkah, pipes as well as made into for chewing and snuffing, tobacco. alkaloids like nicotine, nornicotine and anabasin are present in tobacco. 4. Ornamental Cestrum diurnum Plant Grown in garden as plants (Day Jasmine) ornamental plants for their aesthetic nature. Cestrum nocturnum (Night Jasmine) Do tomatoes come from a tree? Nicotiana alata Petunia hybrida, Schizanthus pinnatus Brugmansia species

(Angel trumpet) Solanum betaceum (Tree tomato)

Extra - Axillary scorpioid cyme

Corolla Stamen Fruit Corolla

Stamen

Solanum trilobatum Atropa belladonna Habit Inflorescence Entire flower

Stigma Apical pore Anther lobe Corolla Style Connective Epipetalous Sepal stamens Ovary Filament Calyx Corolla cut open Stamen Gynoecium

Persistent calyx Ovary wall Berry Placenta Ovule

Fruit C.S.of ovary

Floral formula

Withania somnifera Schizanthus pinnatus Ebr.,Ebrl., , ,K(5),C(5),A5,G(2) Floral diagram

Figure 5.17: Selected plants belongs to Figure 5.58 Solanum nigrum the Family Solanace Figure 5.18: Solanum americanum

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 158 02-06-2018 15:19:10 5.13.3 Monocot Family Family: Liliaceae (Lily Family) Systematic position Bentham and Hooker APG Classification Classification Kingdom: Plantae Kingdom: Plantae Clade: Angiosperms Class: Monocotyledons Clade: Monocots Series: Coronarieae Order: Liliales Order: Liliales Family: Liliaceae Family: Liliaceae

Diagnostic Features • Perennial herbs often with bulbous Note: Liliaceae of Bentham and stem / rhizomes Hooker included Allium, Gloriosa, Smilax, Asparagus, Scilla, Aloe, • Radical leaves Dracaena etc. Now under APG, it • Perianth showy includes only Lilium and Tulipa. • Stamens six All others are placed under different • Ovary superior­­ families. General Characters Distribution: Liliaceae are fairly large Leaf: Leaves are radical (Lilium) or family comprising about 15 genera and 550 cauline (Dracaena), usually alternate, species. Members of this family are widely opposite (Gloriosa), sometimes fleshy distributed over most part of the world. and hollow, reduced to scales (Ruscus and Habit: Mostly perennial herbs Asparagus). The venation is parallel but persisting by means of a sympodial in species of Smilax it is reticulate. Leaves rhizome (Polygonatum), by a bulb are usually exstipulate, but in Smilax, two (Lilium) corm (Colchicum), shrubby or tendrils arise from the base of the leaf, tree like (Yucca and Dracaena). Woody which are considered modified stipules. climbers, climbing with the help of Inflorescence: Flowers are usually stipular tendrils in Smilax. Trees in borne in simple or branched racemes Xanthorrhoea, succulents in Aloe. (Asphodelus) spikes in Aloe, huge terminal Root: Adventitious and fibrous, and panicle in Yucca, solitary and axillary in typically contractile. Gloriosa, solitary and terminal in Tulipa. Stem: Stems usually bulbous, Flowers: Flowers are often showy, rhizomatous in some, aerial, erect pedicellate, bracteate, usually ebracteolate (Dracaena) or climbing (Smilax) in except Dianella and Lilium, bisexual, Ruscus the ultimate branches are modified actinomorphic, trimerous, hypogynous, into phylloclades, In Asparagus stem is rarely unisexual (Smilax) and are dioecious, modified into cladodes and the leaves are rarely tetramerous (Maianthemum), slightly reduced to scales. zygomorphic (Lilium) and hypogynous.

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 159 02-06-2018 15:19:11 Perianth: Tepals 6 biseriate arranged Botanical description of Allium cepa in two whorls of 3 each, apotepalous or (In APG classification, Allium cepa is rarely syntepalous as in Aloe. Usually placed under the family Amaryllidaceae) petaloid or sometimes sepaloid, odd tepal of the outer whorl is anterior in position, Habit: Perennial herb with bulb. valvate or imbricate, tepals more than six Root: Fibrous adventitious root system in Paris quadrifolia. Stem: Underground bulb Androecium: Stamens 6, arranged in 2 whorls of 3 each: rarely stamens are Leaf: a cluster of radical leaves emerges 3 (Ruscus),4 in Maianthemum, or up to from the underground bulb, cylindrical 12, apostamenous, opposite to the tepals, and fleshy having sheathy leaf bases with sometimes epitepalous; filaments distinct parallel venation. or connate, anthers dithecous, basifixed Inflorescence: Scapigerous i.e. the or versatile, extrose, or intrese, dehiscing inflorescence axis (peduncle) arising from usually by vertical slit and sometimes the ground bearing a cluster of flowers by terminal pores; rarely synstamenous at its apex. Pedicels are of equal length, (Ruscus). arising from the apex of the peduncle Gynoecium: Tricarpallary, which brings all flowers at the same level. syncarpous, the odd carpel usually Flower: Small, white, bracteate, anterior, ovary superior, trilocular, with ebrcteolate, pedicellate, complete, trimerous, 2 rows of numerous ovules on axile actinomorphic and hypogynous. Flowers placextation; rarely unilocular with are protandrous. parietal placentation, style usually one; Perianth: Tepals 6, white,arranged stigmas 1 or 3; rarely the ovary is inferior in two whorls of three each, syntepalous (Haemodorum), nectar – secreting septal showing valvate aestivation. glands are present in the ovary. Androecium: Stamens 6, arranged Fruit: Fruit usually a septicidal in two whorls of three each, epitepalous, or loculicidal capsule or a berry as in apostamenous /free and opposite to tepals. Asparagus & Smilax. Anthers dithecous, basifixed, introse, and dehiscing longitudinally. Activity Gynoecium: Tricarpellary and Can you identify this? syncarpous. Ovary superior, trilocular a. Name the family with two ovules in each locule on axile b. Write the binomial placentation. Style simple, slender with c. List the economic uses simple stigma. Fruit: A loculicidal capsule. Seed: Endospermous Floral Formula:

Br.,Ebrl., , ,P(3+3)+A3+3,G(3)

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 160 02-06-2018 15:19:11 Inflorescence Pedicel Bract Flower Peduncle

Cylindrical fleshy leaf Bract Peduncle

Inflorescence

Epitepalous stamen

Filament

Ovary Perianth Bulbose stem Pedicel

Habit Flower entire

Stigma Style Locule Anther Ovule Stigma Ovary Style Ovary Carpel Peduncle L.s of flower Gynoecium C.S. of ovary

Floral formula

Br.,Ebrl., , ,P(3+3)+A3+3,G(3)

Floral diagram Figure 5.19: Allium cepa

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 161 02-06-2018 15:19:11 Economic Importance of the family liliaceae Economic S.No. Binomial Useful part Uses importance 1. Food plant Allium cepa Bulbs Used as vegetable, stimulative, diuretic, expectorant with bactericidal properties. Allium sativum Bulbs Used as condiment and also good for heart. Asparagus officinalis Fleshy shoots Used as vegetables. A. racemosus Tuberous Used as vegetables. roots 2. Medicinal Aloe barbadense Leaves Leaves are the source of plant resinous drug, used as a purgative.

Aloe vera Leaves Gelatinous glycoside called aloin from succulent leaves are used in soothing lotions, piles and inflammations, hemorrhoidal salves and shampoos. Asparagus racemosus Roots Medicinal oil is prepared from the root is used for nervous and rheumatic complaints and also in skin diseases. Colchichum luteum Roots Used in the treatment of gout and rheumatism. Gloriosa superba Tubers Tubers helpful in promoting labour pains in women. Scilla hyacinthiana Bulbs Used as heart stimulant. Smilax glabra and Roots Used in the treatment of S.ovalifolia venereal diseases. 3. Fibre Phormium tenax Fibre Used for cordage, fishing yielding net, mattings, twines plant 4. Raticides Urginea indica Bulbs Used for killing rats Insecticides Veratrum album Bulbs Used as insecticide.

Continued

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 162 02-06-2018 15:19:11 Economic S.No. Binomial Useful part Uses importance 5. Polyploidy Colchicum luteum is Corm Colchicine (alkaloid) used to induce polyploidy. 6. Ornamental Agapanthus Plant Some of the well known plants africanus garden ornamentals. (Africian Lilly) Hemerocallis fulva (Orange Day Lilly) Gloriosa superba (Malabar glory lilly) Lilium candidum Lilium giganteum Ruscus aculeatus (Butchers Broom) Tulipa suaveolens Yucca alcifolia and Y.gloriosa

In Yucca the cross- pollination carried out by special moth, Pronuba yuccasella. Fully opened flowers emit perfumes and are visited by the female Lilium nilgiriensis Smilax moth, especially during nights. This moth collects a lot of pollen grains from one flower and visits another flower. Life history of this moth is intimately associated with the pollination mechanism in Yucca. Tulipa Ruscus

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 163 02-06-2018 15:19:14 State Flower of Tamil Nadu Gloriosa superba

Anthers extrose Ascrambling or and versatile. climbing plant.

leaves subopposite, the leaf tip is modified into The flower petals, wavy on tendril. the edges, tend to start yellow near the vine, then become a flaming red closerto the outer edges.

The plant contain the alkaloid colchicine. It is widely used as an experimental tool in the study of cell division

Petals have wavy edges and are strongly turned Fruit is a fleshy capsule. backwards.

The name of Gloriosa superba is composed of two greek words Gloriosa means full of glory, superba means superb. This plant was placed earlier in Liliaceae.

Summary scope for botanical research, conservation Taxonomy deals with the identification, naming of rare species and propagation of many and classification of plants. But systematics species. Botanical survey of India explores deals with evolutionary relationship between and documents biodiversity all over India. It the organisms in addition to taxonomy. has 11 regional centres in India. Herbarium Taxonomic hierarchy was introduced by preparation includes plant collection, Carolus Linnaeus. It includes ranks. Species documentation of field data, preparation of is the fundamental unit of taxonomic plant specimens and mounting and labeling. classification. Species concept can be classified There are several national and international into two groups based on the process of herbaria. National herbaria include MH, evolution and product of evolution. There PCM, CAL etc. Kew herbarium is the world’s are three types of species, morphological, largest one. biological and phylogenetic species. Type Classification is the basis for cataloguing and concept emphasizes that a specimen must retrieving information about the tremendous be associated with the scientific name which diversity of flora. It helps us to know about is known as nomenclatural type. There are different varieties, their phylogenetic relationship different types and they are holotype, isotype, and exact position. Some important systems of lectotype etc. Taxonomic aids are the tools classification are fall in to three types; artificial, for the taxonomic study such as keys, flora, natural and phylogenetic. Carolus Linnaeus revisions, catalogues, botanical gardens and outlined an artificial system of classification in herbaria. Botanical gardens serve different “Species Plantarum” in 1753. The first scheme purposes. They have aesthetic value, offers of classification based on overall similarities

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 164 02-06-2018 15:19:15 was presented by Antoine Laurent De Jessieu mitochondrial DNA, microsatellites, RAPDs, in 1789. A widely followed natural system of AFLPs, single nucleotide polymorphism- classification was proposed by George Bentham SNP, microchips or arrays are used in analysis. (1800 - 1884) and Joseph Dalton Hooker. This Molecular Taxonomy unlocks the treasure system was not intended to be phylogenetic. chest of information on evolutionary history of One of the earliest phylogenetic systems of organisms.It plays a vital role in phytogeography, classification was jointly proposed by Adolf which ultimately helps in genome mapping Engler and Karl A Prantl in a monumental work and biodiversity conservation. DNA barcoding “Die Naturelichen Pflanzen Familien”. Arthur is a taxonomic method that uses a very short Cronquist proposed phylogenetic classification genetic sequence from a standard part of a of flowering plants based on a wide range of genome. It helps in identification of organisms. taxonomic characters including anatomical and phytochemical of phylogenetic importance in Evaluation his book titled “The evolution and classification 1. Specimen derived from non-original of flowering plants.”Angiosperm phylogeny collection serves as group (APG) classification is the most recent the nomenclatural type, when original classification of flowering plants based on specimen is missing. It phylogenetic data. APG system is an evolving is known as and currently accepted system across the world a. Holotype b. and followed by all the leading taxonomic Neotype institutions and practising taxonomists. c. Isotype d. Cladistics is the methodology, used to Paratype classify organisms into monophyletic groups, 2. Phylogenetic classification is the most favoured classification because it reflects consisting of all the descents of the common a. Comparative Anatomy ancestors. The outcome of a cladistic analysis is b. Number of flowers produced a cladogram and is construed to represent the c. Comparative cytology best hypothesis of phylogenetic relationships. d. Evolutionary relationships Chemotaxonomy is the scientific approach 3. The taxonomy which involves the of classification of plants on the basis of similarities and dissimilarities among their biochemical constituents in them. the immune system of different taxa is Utilization of the characters of chromosome termed as for the taxonomic inference is known as a. Chemotaxonomy karyotaxonomy. The application of serology b. Molecular systematics in solving taxonomic problems is called c. Serotaxonomy serotaxonomy. Molecular Taxonomy is the d. Numerical taxonomy branch of phylogeny that analyses hereditary 4. Which of the following is a flowering plant molecular differences, mainly in DNA nuclear with nodules containing filamentous and chloroplast sequences, to gain information nitrogen fixing micro - organisms? and to establish genetic relationship between a. Crotalaria juncea the members of different taxonomic categories. b. Cycas revoluta Different molecular markers like allozymes, c. Cicer arietinum d. Casuarina equisetifolia

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 165 02-06-2018 15:19:15 5. Flowers are zygomorphic in 8. How does molecular markers work a. Ceropegia b. Thevetia to unlock the evolutionary history of c. Datura d. Solanum organisms? 6. What is the role of national gardens in 9. Give the floral characters of Clitoria conserving biodiversity – discuss ternatea. 7. Where will you place the plants which 10. How will you distinguish Solanaceae contain two cotyledons with cup shaped members from Liliaceae members? thalamus?

ICT Corner C h a r a c t e r o f fl o w e r

Look inside the Flower.

Steps • Scan the QR code or go to google play store • Type online labs and install it. • Select biology and select Character of flower • Click theory to know the basic about Character of flower • Register yourself with mail-id and create password to access online lab simulations Activity • Select simulation and dissect the different flowers • Record your observations

Step 2 Step 4

Step 1 Step 3 URL:

https://play.google.com/store/apps/details?id=in.edu.olabs.olabs&hl=en * Pictures are indicative only

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TN_GOVT_BOTANY_XI_Page 124-166 CH05.indd 166 02-06-2018 15:19:17