Downloaded from https:// www.studiestoday.com

Chapter and 5 Systematic Botany

Plants are the prime companions of Learning Objectives human beings in this universe. 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, , Taxonomy has witnessed various Solanaceae, , phases in its early history to the present day and Liliaceae. 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 – Morphological, Biological and Phylogenetic Theophrastus (372 – 287 BC), the 5.4 International Code of Greek Philosopher known as “Father of Botanical 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 Botanicalhttps://www.studiestoday.com Gardens described and illustrated in his famous 5.8 Herbarium – Preparation and uses “Materia medica” and described about 600 5.9 Classification of Plants medicinal plants. From 16th century onwards 5.10 Types of classification Europe has witnessed a major developments 5.11 Modern trends in the field of Taxonomy. Some of the key in taxonomy contributors include Andrea Caesalpino, John 5.12 Cladistics Ray, Tournefort, Jean Bauhin and Gaspard 5.13 Selected Families Bauhin. Linnaeus ‘Species Plantarum' (1753) of Angiosperms

160

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 160 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

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 Though there were earlier usages of and also Modern Biotechnology, the term ‘systematics’, only during the Molecular Biology and Bioinformatics. It latter half of 20th century ‘Systematics’ helps 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. 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 https://www.studiestoday.comLinnaeus. 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: . 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

161

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 161 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

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 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”. Accordinghttps://www.studiestoday.com 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.

162

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 162 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

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 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 https://www.studiestoday.comwhich 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.

163

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 163 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

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 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, 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. https://www.studiestoday.comThese 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

164

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 164 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

erecto folius compositis. It means butter Standard form of author’s abbreviations cup with reflexed sepals, curved 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 Pithecellobiumhttps://www.studiestoday.com 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.

165

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 165 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

Syntype: When more than one specimen Example: cited by the author in the protologue 1. a)  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 andhttps://www.studiestoday.com 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.

166

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 166 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

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 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 or exact title of the book, exact date of species at a given time. This includes the publication the particulars of edition. existing taxonomic knowledge and all Example: Catalogue of the Library of British 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 https://www.studiestoday.comvalue, religious and status reasons. The Revisions famous “hanging gardens” of Babylon in Mesopotamia is an example. For the Taxonomic revision is carried out for purpose of science and education the first a family or genus. Usually taxonomic garden was maintained by Theophrastus revision is less comprehensive than a in his public lecture hall at Athens. monograph for a given geographical area. 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.

167

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 167 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

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- https://www.studiestoday.comBambusetum (69 species)

Figure 5.1: National Botanical Garden

168

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 168 02-06-2018 15:04:27 Downloaded from https:// www.studiestoday.com

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 Royal Botanichttps://www.studiestoday.com garden Kew- England collection, Collection for molecular is a non- departmental public body studies. in the United Kingdom. It is the 2. Documentation of field site data largest botanical garden in the world, 3. Preparation of plant specimen established in 1760, but officially opened 4. Mounting herbarium specimen in the year 1841. 5. Herbarium labels. 6. Protection of herbarium sheets against mold and insects

169

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 169 02-06-2018 15:04:28 Downloaded from https:// www.studiestoday.com

Preparation of herbarium Specimen

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, longitude, image document, collection number, date of collection and name of the collector. https://www.studiestoday.comWorld’s smallest water – lily Nymphaea Protection of herbarium sheets against thermarum was saved mold and insects Applycation of 2% Mercuric chloride, f r o m Naphthalene, DDT, carbon disulphide. Fu- extinction when it was migation using formaldehyde. Presently deep grown from seed at Kew freezing(-20oC) method is followed through- out the world. in 2009.

170

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 170 02-06-2018 15:04:28 Downloaded from https:// www.studiestoday.com

International Herbarium

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. Voucherhttps://www.studiestoday.com 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.

171

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 171 02-06-2018 15:04:29 Downloaded from https:// www.studiestoday.com

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 https://www.studiestoday.comabout 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.

172

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 172 02-06-2018 15:04:29 Downloaded from https:// www.studiestoday.com

Taxonomists have assigned a method 24 classes recognized by Linnaeus in his of classifying organisms which are called Species Plantarum (1753) on the basis of ranks. These taxonomical ranks are stamens. hierarchical. The scheme of classification has to be flexible, allowing newly No Classes Characters discovered living organisms to be added 1 Monandria stamen one where they fit best. 2 Diandria stamens two 5.9.1 Need for Classification 3 Triandria stamens three 4 Tetrandria stamens four • Understanding the classification of 5 Pentandria stamens five organisms can gives an insight in to other 6 Hexandria stamens six fields and has significant practical value. 7 Heptandria stamens seven • Classification helps us to know about 8 Octandria stamens eight different taxa, their phylogenetic 9 Ennandria stamens nine relationship and exact position. 10 Decandria stamens ten • It helps to train the students of plant 11 Dodecandria stamens 11-19 sciences with regard to the diversity of 12 Icosandria stamens 20 or more, organisms and their relationship with on the calyx other biological branches. 13 Polyandria stamens 20 or more, on the receptacle 5.10 Types of classification 14 Didynamia stamens didynamous; Taxonomic entities are classified in three 2 short, 2 long ways. They are artificial classification, 15 Tetradynamia stamens tetradyna- natural classification and phylogenetic mous; 4 long, 2 short classification. 16 Monadelphia stamens monadelphous; united 5.10.1 Artificial system of classification in 1 group Carolus Linnaeus (1707 -1778) was a great 17 Diadelphia stamens diadelphous; Swedish Botanist and said to be the “Father united in 2 groups of Taxonomy.” 18 Polyadelphia stamens He outlined an polyadelphous; united artificial system in 3 or more groups of classification 19 Syngenesia stamens syngenesious; in https://www.studiestoday.com“Species united by anthers only Plantarum” in 20 Gynandria stamens united with 1753, wherein he the gynoecium listed and described 21 Monoecia plants monoecious 7,300 species and 22 Dioecia plants dioecious arranged in 24 23 Polygamia plants polygamous classes mostly 24 Cryptogamia flowerless plants on the basis of Figure 5.4: number, union Carolus Linnaeus

173

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 173 02-06-2018 15:04:29 Downloaded from https:// www.studiestoday.com

(adhesion and cohesion), length, and Bentham and Hooker system of distribution of stamens. The classes were classification further subdivided on the basis of carpel characteristics into orders. Hence the system of classification is also known as sexual system of classification. This system of classification though artificial, was continued for more than 100 years after the death of Linnaeus, due to its simplicity and easy way of identification of plants. However the system could not hold Figure 5.5: George Bentham and good due to the following reasons. J.D. Hooker. 1. Totally unrelated plants were kept in A widely followed natural system of a single group, whereas closely related classification considered the best was plants were placed in widely separated proposed by two English botanist groups. Example: George Bentham (1800 - 1884) and Joseph Dalton Hooker (1817–1911). The a. of classification was published in a three and Anacardiaceae of dicotyledonous volume work as “Genera Plantarum” were placed under the class (1862–1883) describing 202 families Monandria since these possess and 7569 genera and 97, 205 species. single stamens. In this system the seeded plants were b. Prunus was classified along with classified into 3 major classes such as Cactus because of the same number Dicotyledonae, Gymnospermae and of stamens. Monocotyledonae. 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 https://www.studiestoday.comMonochlamydeae. 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 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.

174

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 174 02-06-2018 15:04:29 Downloaded from https:// www.studiestoday.com

Seed plants

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 (i) Thalamiflorae: Plants and dichlamydeous are placed under having flowers with dome or conical Gamopetalae. It is further divided into shaped thalamus and superior ovary are three series – Inferae, Heteromerae and included in this series. It includes 6 orders Bicarpellatae. and 34 families. Series (i) Inferae: The flowers are Series (ii) Disciflorae: Flowers having epigynous and with inferior ovary. Inferae prominent disc shaped thalamus with includes 3 orders and 9 families. superior ovary come under this series. It Series (ii) Heteromerae: The flowers includes 4 orders and 23 families. are hypogynous, superior ovary and with Serieshttps://www.studiestoday.com (iii) Calyciflorae: It includes plants more than two carpels. Heteromerae having flowers with cup shaped thalamus includes 3 orders and 12 families. and with inferior or sometimes with half Series (iii) Bicarpellatae: The flowers inferior ovary. Calyciflorae includes 5 orders are hypogynous, superior ovary and with and 27 families. two carpels.Bicarpellatae includes 4 orders Sub-class 2. Gamopetalae: Plants with and 24 families. united petals, which are either partially Sub-class 3. Monochlamydeae: Plants or completely fused to one another with incomplete flowers either apetalous

175

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 175 02-06-2018 15:04:29 Downloaded from https:// www.studiestoday.com

or with undifferenciated calyx and corolla and not mere comparisons of known are placed under Monochlamydeae. The facts. sepals and petals are not distinguished and • As it is easy to follow, it is used as a key they are called perianth. Sometimes both for the identification of plants in several the whorls are absent. Monochlamydeae herbaria of the world. includes 8 series and 36 families. Though it is a natural system, Class II Gymnospermae: Plants that this system was not intended to be contain naked seeds come under this class. phylogenetic. Gymnospermae includes three families – Gnetaceae, Coniferae and Cycadaceae. 5.10.3 Phylogenetic system of classification Class III Monocotyledonae: Plants contain only one cotyledon in their seed, The publication of the Origin of Species leaves with parallel venation, fibrous root (1859) by Charles Darwin has given system and trimerous flowers come under stimulus for the emergence of phylogenetic this class. The Monocotyledonae has system of classification. 7 series and 34 families. I Adolph Engler and Karl A Prantl The Bentham and Hooker system of system of classification classification is still supposed to be the best One of the earliest phylogenetic system of system of classification. It has been widely classification of the entire plant Kingdom practiced in colonial countries and herbaria was jointly proposed by two German of those countries were organised based on botanists Adolph Engler ( 1844 -1930) and this system and is still used as a key for the Karl A Prantl (1849 - 1893). They published identification of plants in some herbaria of their classification in a monumental work the world due to the following reasons: “Die Naturelichen Pflanzen Familien” in • Description of plants is quite accurate 23 volumes (1887- 1915) and reliable, because it is mainly based on In this system of classification the plant personal studies from actual specimens kingdom was divided into 13 divisions. The

Division: Embryophyta (Siphonogama)

Sub-division:Gymnospermae Sub-division: Angiospermae https://www.studiestoday.com 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 5.7: Outline of Engler and Prantl classification

176

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 176 02-06-2018 15:04:29 Downloaded from https:// www.studiestoday.com

characters including anatomical and phytochemical characters of phylogenetic importance. He has presented his classification in 1968 in his book titled “The evolution and classification of flowering plants.” His classification is broadly based on the Principles of phylogeny that finds acceptance with major contemporary authors. Figure 5.8: Adolph Engler and Karl A Prantl

first 11 divisions are Thallophytes, twelfth division is Embryophyta Asiphonogama (plants with embryos but no pollen tubes; Bryophytes and Pteridophytes) and the thirteenth division is Embryophyta Siphonogama (plants with embryos and pollen tubes) which includes seed plants. II Arthur Cronquist system of classification Figure 5.9: Arthur Cronquist Arthur Cronquist (1919 - 1992) an eminent Cronquist classified the angiosperms American taxonomist proposed into two main classes Magnoliopsida phylogenetic classification of flowering (=dicotyledons) and Liliopsida plants based on a wide range of taxonomic

Rosidae (5) )

Asteridae (6 4. Zingiberidae

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

https://www.studiestoday.comMagnoliidae 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.

177

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 177 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

(= monocotyledons). There are Amborellales 6 subclasses, 64 orders, 320 families and Nymphaeales about 165,000 species in Magnoliopsida, Austrobaileyales

EARLY Magnoliids whereas in Liliopsida there are 5 sub

ANGIOSPERMS Chloranthales classes, 19 orders, 66 families and about MONOCOTS Monocots Musaceae 50,000 species. Family: Liliaceae Ceratophyllales Cronquist system of classification Ranunculales also could not persist for a long time Proteales

EUDICOTS Torchodendrales

because, the system is not very useful Early Buxales diverging for identification and cannot be adopted Gunnerales Dilleniales in herbaria due to its high phylogenetic Saxifragales nature. Super rosids Fabaceae Family: Euphorbiaceae 5.10.4 Angiosperm phylogeny group Berberidopsidales Santalales

(APG) classification Super Caryophyllales Asterids The most recent classification of Apocynaceae Family: Solanaceae flowering plants based on phylogenetic Figure 5.11: Simplified version of APG IV data was set in the last decade of ( Source: Plant Gateway's The Global Flora, twentieth century. Four versions of Vol. I January 2018 ) Angiosperm Phylogenetic Group Angiosperms are classified into three classification (APG I, APG II, APG III clades early angiosperms, monocots & APG IV) have been published in 1998, and eudicots. Early angiosperms are classified into 8 orders and 2003, 2009 and 2016 respectively. Each 26 families (ANA-grade + magnoliids version supplants the previous version. + Chloranthales) Recognition of monophyletic group Amborellales based on the information received Nymphaeales from various disciplines such as gross Austrobaileyales morphology, anatomy, embryology, ➢ Seeds always with two cotyledons. palynology, karyology, phytochemistry and more strongly on molecular data ➢ Presence of ethereal oils. with respect to DNA sequences of two ➢ Leaves are always simple net-veined. chloroplast genes (atpB and rbcL) and ➢ Each floral whorls with many parts. one nuclearhttps://www.studiestoday.com gene (nuclear ribosomal ➢ Perianth usually spirally arranged 18s DNA). or parts in threes. The most recent updated version, ➢ Stamens with broad filaments. APG IV (2016) recognised 64 orders and ➢ Anthers tetrasporangiate. 416families. Of these, 416 families 259 are ➢ Pollen monosulcate. represented in India. ➢ Nectaries are rare. The outline of APG IV classification is given below. ➢ Carpels usually free and. ➢ Embryo very small.

178

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 178 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

Monocots are classified into 11 orders ➢ Seeds with always two cotyledons. and 77 families (basal monocots + lilioids ➢ Nodes trilacunar with three leaf traces. + ) ➢ Stomata anomocytic. ➢ Seeds with single cotyledon. ➢ Ethereal oils rarely present. ➢ Primary root short-lived. ➢ Woody or herbaceous plants. ➢ Single adaxial prophyll. ➢ Leaves simple or compound, usually ➢ Ethereal oils rarely present. net-veined. ➢ Mostly herbaceous, absence of ➢ Flower parts mostly in twos, fours vascular cambium. or fives. ➢ Vascular bundles are scattered in the ➢ Microsporogenesis simultaneous. stem. ➢ Style solid and . ➢ Leaf simple with parallel-veined. ➢ Pollen tricolpate. ➢ Floral parts usually in threes. APG system is an evolving system that ➢ Perianth often composed of tepals. might undergo change periodically based on ➢ Pollen monosulcate. the new sets of data from various disciplines ➢ Styles normally hollow and. of Botany. It is the currently accepted system across the world and followed by ➢ Successive microsporogenesis. all the leading taxonomic institutions and Eudicots are divided into 45 orders and practising taxonomists. However, it is 313 families (early diverging eudicots + yet to percolate into the Indian botanical super rosids + super asterids). curriculum.

Changes in earlier taxonomic understanding. The newly proposed APG classification system has brought many changes in our earlier understanding on the concept of primitive families. Some of them are given below: • The real Ranalean families, especially the arborescent ones are no more the primitive families. But as per APG classification system, Amborellaceae, Nymphaceae, Austrobaileyaceae, Magnoliaceae and Chloranthaceae form the early angiosperms. • Monocots are recognised as a monophyletic group and hence terminology is retained. • Dicots are polyphyletic group and as a result the use of the term dicotyledons as a grouphttps://www.studiestoday.com becomes outdated. • Liliaceae (Sensu lato) is split into 14 families. • Molluginaceae and Gisekiaceae are recognised separately from Aizoaceae. • Euphorbiaceae (s.l.) is split in to , Picrodendraceae and Putranjivaceae. • Asclepiadaceae are merged with Apocynaceae (s.l.) • Many genera that were conventionally treated under Verbenaceae such as Clerodendron, Tectona and Vitex are transferred to Lamiaceae based on the modified circumscription of these families.

179

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 179 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

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 ) Classification reflects the state of our taxonomy is possible with the principles of knowledge at a given point of time. It will various disciplines like Cytology, Genetics, continue to change as we acquire new Anatomy, Physiology, Geographical information. Distribution, Embryology, Ecology, Palynology, Phenology, Bio-Chemistry, A significant number Numerical Taxonomy and Transplant of major herbaria, Experiments. These have been found to be including Kew are useful in solving some of the taxonomical changing the order of problems by providing additional their collections in accordance with APG. characters. It has changed the face of classification from alpha (classical) to omega The influential world checklist (modern kind). Thus the new systematic has of selected plant families (also from evolved into a better taxonomy. kew) is being updated to the APG III system. 5.11.1 Chemotaxonomy A recent photographic survey Various medicines, spices and preservatives of the plants of USA and Canada is obtained from plant have drawn the attention of Taxonomists. Study of organized according to the APG III various chemicals available in plants help system. to solve certain taxonomical problems. In UK, the latest edition of the Chemotaxonomy is the scientific approach standard flora of the British Isles of classification of plants on the basis of their written by Stace is based on the APG biochemical constituents. As proteins are III system. more closely controlled by genes and less https://www.studiestoday.comsubjected to natural selection, it has been used at all hierarchical levels of classification starting from the rank of ‘variety’ up to the 5.11 Modern trends in taxonomy rank of division in plants. Proteins, amino Taxonomists now accept that, the acids, nucleic acids, peptides etc. are the most morphological characters alone should not studied chemicals in chemotaxonomy. be considered in systematic classification The chemical characters can be divided of plants. The complete knowledge of into three main categories.

180

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 180 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

1. Easily visible characters like starch 5.11.3 Karyotaxonomy grains, silica etc. Chromosomes are the carriers of genetic 2. Characters detected by chemical tests information. Increased knowledge about like phenolics, oil, fats, waxes etc. the chromosomes have been used for 3. Proteins extensive biosystematic studies and resolving many taxonomic problems. Aims of chemotaxonomy Utilization of the characters and 1. To develop taxonomic characters phenomena of cytology for the explanation which may improve existing system of taxonomic problem is known as of plant classification. cytotaxonomy or karyotaxonomy. The 2. To improve present day knowledge characters of chromosome such as number, of phylogeny of plants. size, morphology and behaviour during meiosis have proved to be of taxonomic 5.11.2 Biosystematics value. Biosystematics is an “Experimental, ecological and cytotaxonomy” through 5.11.4 Serotaxonomy (immunotaxonomy) which life forms are studied and their Systematic serology or serotaxonomy had relationships are defined. The term its origin towards the end of twentieth biosystematics was introduced by Camp century with the discovery of serological and Gilly in 1943. Many authors feel reactions and development of the discipline Biosystematics is closer to Cytogenetics of immunology. The classification of very and Ecology and much importance given similar plants by means of differences in the not to classification but to evolution. proteins they contain, to solve taxonomic problems is called serotaxonomy. Aims of biosystematics Smith (1976) defined it as “the study of The aims of biosystematics are as follows: the origins and properties of antisera.” 1. To delimit the naturally occurring biotic community of plant species. Importance of serotaxonomy It determines the degree of similarity 2. To establish the evolution of a between species, genera, families etc. by group of taxa by understanding comparing the reactions of antigens from the evolutionary and phylogenetic various plant taxa with antibodies raised trends. against the antigen of a given taxon. 3. Tohttps://www.studiestoday.com involve any type of data Example: 1. The assignment of gathering based on modern Phaseolus aureus and P. mungo to the genus concepts and not only on Vigna is strongly supported by serological morphology and anatomy. evidence by Chrispeels and Gartner. 4. To recognize the various groups as separate biosystematic categories 5.11.5 Molecular taxonomy (molecular such as ecotypes, ecospecies, systematics / molecular phylogenetics) cenospecies and comparium. Molecular Taxonomy is the branch of phylogeny that analyses hereditary

181

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 181 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

molecular differences, mainly in DNA population genetics over the years. These sequences, to gain information and to modern methods have revolutionised the establish genetic relationship between the field of molecular taxonomy and population members of different taxonomic categories. genetics with improved analytical power The advent of DNA cloning and sequencing and precision. methods have contributed immensely to the The results of a molecular development of molecular taxonomy and phylogenetic analysis are expressed in

Molecular Markers Allozyme electrophoresis is a method which can identify genetic variation at the level of enzymes that are directly encoded by DNA. Mitochondrial DNA markers are non- nuclear DNA located within organelles in the cytoplasm called mitochondria. The entire genome undergoes transcription as one single unit. They are not subjected to recombination and thus they are homologous markers. Microsatellite is a simple DNA sequence which is repeated several times across various points in the DNA of an organism. These (usually 2-5) repeats are highly variable and these loci can be used as markers. (Example: TGTGTG, in which two base pairs repeat, the region are termed tandem repeat.) Single nucleotide polymorphisms arise due to single nucleotide substitutions (transitions/transversions) or single nucleotide insertions/deletions. SNPs are the most abundant polymorphisms in the genome (coding and non-coding) of any organism. These single nucleotide variants can be detected using PCR, microchip arrays or fluorescence technology. DNA microarray or DNA chip consists of small glass microscope slides, silicon chip or nylon membranes with many immobilized DNA fragments arranged in a standard pattern. A DNA microarray can be utilized as a medium for matching a reporter probe of known sequence against the DNA isolated from the target sample which is of unknown origin. Species-specific DNA sequences could be incorporated to a DNA microarray and this could be used for identification purposes. Arbitrary markers are sometimes used to target a segment of DNA of unknown function. The widely used methods of amplifying unknown regions are RAPD and AFLP DNA.https://www.studiestoday.com Specific Nuclear DNA markers: Variable Number of Tandem Repeat is a segment of DNA that is repeated tens or even hundreds to thousands of times in nuclear genome. They repeat in tandem; vary in number in different loci and differently in individuals. There are two main classes of repetitive and highly polymorphic DNA viz. minisatellite DNA referring to genetic loci with repeats of length 9-65 bp and microsatellite DNA with repeats of 2-8 bp (1-6) long. Microsatellites are much more numerous in the genome of vertebrates than minisatellites.

182

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 182 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

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 Uses of molecular taxonomy (within the limits of PCR) then the reaction will amplify this region of DNA. 1. Molecular taxonomy helps in establishing the relationship of RAPDs like microsatellites may often be used for genetic studies within species different plant groups at DNA level. but may also be successfully employed 2. It unlocks the treasure chest of in phylogenetic studies to address information on evolutionary history of relationships within a species or between organisms. closely related species. However RAPD RFLP (Restriction Fragment Length analysis has the major disadvantage that Polymorphism) results are difficult to replicate and in that RFLPs is a molecular method of genetic the homology of similar bands in different analysis that allows identification of taxa taxa may be nuclear. based on unique patterns of restriction Significance of Molecular Taxonomy sites in specific regions of DNA. It refers 1. It helps to identify a very large number to differences between taxa in restriction of species of plants and animals by the sites and therefore the lengths of fragments use of conserved molecular sequences. of DNA following cleavage with restriction enzymes. 2. Using DNA data evolutionary patterns of biodiversity are now investigated. Amplified Fragment Length 3. DNA taxonomy plays a vital role in Polymorphism (AFLP) phytogeography, which ultimately This method is similar to that of helps in genome mapping and identifying RFLPs in that a restriction biodiversity conservation. enzyme is used to cut DNA into numeroushttps://www.studiestoday.com smaller pieces, each of which 4. DNA- based molecular markers used terminates in a characteristic nucleotide for designing DNA based molecular sequence due to the action of restriction probes, have also been developed under enzymes. the branch of molecular systematics. AFLP is largely used for population 5.11.6 DNA Barcoding genetics studies, but has been used in studies of closely related species and even Have you seen how scanners are used in in some cases, for higher level cladistic supermarkets to distinguish the Universal analysis. Product Code (UPC)? In the same way we

183

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 183 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

can also distinguish one species from another. 5.11.7 Differences between classical and DNA barcoding is a taxonomic method that modern taxonomy uses a very short genetic sequence from Classical Taxonomy Modern Taxonomy a standard part of a genome. The genetic It is called old It is called sequence used to identify a plant is known systematics or Alpha Neosystematics or as “DNA tags” or “DNA barcodes”. Paul (ἀ) taxonomy or Biosystematics or Hebert in 2003 proposed ‘DNA barcoding’ Taxonomy Omega (Ω) taxonomy and he is considered as ‘Father of barcoding’. It is pre Darwinean It is post ­Darwinean The gene region that is being used as Species is considered species is considered an effective barcode in plants is present as basic unit and is as dynamic entity and in two genes of the chloroplast, matK static ever changing Classification is Classification is and rbcL, and have been approved as the mainly based on based on morpho- barcode regions for plants. morphological logical, reproduc- Sequence of unknown species can be characters tive characters and matched from submitted sequence in phylogenetic (evolu- GenBank using Blast (web-programme for tionary) relationship of the organism searching the closely related sequence). This system is based This system is based Significance of DNA barcoding on the observation of on the observation of 1. DNA barcoding greatly helps in a few samples/ large number of sam- individuals ples/individuals identification and classification of organism. 5.12 Cladistics 2. It aids in mapping the extent of Analysis of the taxonomic biodiversity. data, and the types of DNA barcoding techniques require a characters that are used in large database of sequences for comparison classification have changed and prior knowledge of the barcoding region. from time to time. Plants However, DNA barcoding is a helpful have been classified based tool to determine the authenticity of on the morphology before botanical material in whole, cut or the advancement of microscopes, which powdered form. help in the inclusions of sub microscopic List of conferences of International and microscopic features. A closer study Barcodehttps://www.studiestoday.com was held is necessary while classifying closely S.No. Year Place related plants. Discovery of new finer 1. 2005 London, United Kingdom molecular analytical techniques coupled 2. 2007 Taipei, Taiwan with advanced software and computers 3. 2009 Mexico City, Mexico 4. 2011 Adelaide, Australia has ushered in a new era of modern or 5. 2013 Yunnan, China phylogenetic classification. 6. 2015 Guelph, Canada The method of classifying organisms into 7. 20-24 Skukuza, South Africa Nov' 2017 monophyletic group of a common ancestor

184

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 184 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

based on shared apomorphic characters is ii. Paraphyletic group; Taxon that called cladistics (from Greek, klados-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 be morphological such as, leaf, flower, fruit, creating phylogenetic system of seed and so on; behavioural, like opening of classifications. flowers nocturnal/diurnal; molecular like, 2. Cladistics produces a hypothesis about DNA or protein sequence and more. the relationship of organisms to predict the morphological characteristics of Cladistics accept only monophyletic organism. groups. Paraphyletic and polyphyletic 3. Cladistics helps to elucidate mechanism taxa are occasionally considered when of evolution. such taxa conveniently treated as one group for practical purposes. Example: 5.13 Selected Families of Angiosperms dicots, sterculiaceae. Polyphyletic groups are rejected by cladistics. Dicot Families i. Monophyletic group; Taxa Plant kingdom is so vast and varied. comprisinghttps://www.studiestoday.com all the descendants of a For the purpose of study, they have common ancestor. been classified into Artificial, Natural, Phylogenetic and APG system in C A D B course of time. Bentham and Hooker system of classification is followed in India till recently. Great variation occurs not only in different families, but also varies in genera and species

185 Downloaded from https:// www.studiestoday.com

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 185 02-06-2018 15:04:30 Downloaded from https:// www.studiestoday.com

which are included within the of the floral parts. We study a few family. Variation occurs in number, families for understanding the process arrangement, adhesion and cohesion and purpose of classification. 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 trees (Sesbania), climbers (Clitoria), large tree (Pongamia, Dalbergia, Erythrina, • Leaves simple or imparipinnately compound or palmate, leaf base Butea), woody climber (Mucuna), pulvinate, leaflets stipellate. hydrophyte (Aeschynomene aspera) commonly called pith plant. • Flowers Zygomorphic Root: Tap • Corolla: Papilionaceous, descendingly root system, imbricate aestivation, posterior roots are outermost, nodulated, • Petals clawed. have tubercles • Stamens: Monadelphous, diadelphous containing Root nodule • Ovary stipitate (a short stalk as the nitrogen – fixing base), monocarpellary, unilocular with bacteria (Rhizobium leguminosarum) marginal placentation. Stem: Aerial, herbaceous, woody • Fruit a legume or lomentum. (Dalbergia) twining or climbing Clitoria. General characters Leaf: Leaf simple or unifoliate (Desmodium gangeticum) bifoliate (Zornia Distribution: Fabaceae includes about 741 genera andhttps://www.studiestoday.com more than 20,200 species. The diphylla,), Trifoliate (Lablab purpureus), members are cosmopolitan in distribution unipinnate or simple pinnate (Clitoria), but abundant in tropical and subtropical alternate, stipulate, leaf base, pulvinate, regions. stipulus 2, free. Leaves showing reticulate Habit: All types of habits are venation terminal leaflet modifies into a represented in this family. Mostly herbs tendril in Pisum sativum. (Indigofera, Crotalaria), prostrate Inflorescence: Raceme (Crotalaria (Indigofera enneaphylla) erect (Crotalaria verrucosa), panicle (Dalbergia latifolia) verrucosa), shrubs (Cajanus cajan), small axillary solitary (Clitoria ternatea)

186

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 186 02-06-2018 15:04:31 Downloaded from https:// www.studiestoday.com

Flowers: Bracteate, bracteolate Fruit: The characteristic fruit of (Sesbania), pedicellete, complete, bisexual, Fabaceae is a legume (Pisum sativum), pentamerous, heterochlamydeous, sometimes indehiscent and rarely a zygomorphic hypogynous or sometimes lomentum (Desmodium). perigynous. In Arachis hypogea the fruit is Calyx: Sepals 5, green, synsepalous, geocarpic (fruits develops and matures more or less united in a tube and persistant, from underground). After fertilization valvate or imbricate, odd sepal is anterior the stipe of the ovary becomes in position. meristematic and grows down into the soil. This ovary gets buried into the soil Corolla: Petals 5, apopetalous, and develops into fruit. unequal and papilionaceous, vexillary or descendingly imbricate aestivation Seed: Endospermic or non- all petals have claw at the base. The endospermic (Pisum sativum), mostly outer most petal is large called standard reniformed. petal or vexillum, Lateral 2 petals are Botanical description of Clitoria lanceolate and curved. They are called ternatea (Sangu pushpam) wing petals or alae. Anterior two petals are partly fused and are called keel Habit: Twining climber petals or carina which encloses the Root: Branched tap root system having stamens and pistil. nodules. Androecium: Stamens 10, diadelphous, Stem: Aerial, weak stem and a twiner usually 9+1 (Clitoria ternatea). The Leaf: Imparipinnately compound, odd stamen is posterior in position. alternate, stipulate showing reticulate In Aeschynomene aspera, the stamens venation. Leaflets are stipellate. Petiolate are fused to form two bundles each and stipels are pulvinated. containing five stamens (5)+5. Stamens Inflorescence: Solitary and axillary are monadelphous and dimorphic Flower: Bracteate, bracteolate, bracteoles ie. 5 stamens have longer filaments and usually large, pedicellate, ­heterochlamydeous, other 5 stamens have shorter filaments complete, bisexual, pentamerous, zygomor- thus the stamens are found at two levels phic and hypogynous. and the shape of anthers also varies in Calyx: Sepals 5, synsepalous, green (Crotalaria verrucosa). (5 anthers are long showing valvate aestivation. Odd sepal is and lanceolate,https://www.studiestoday.com and the other 5 anthers are anterior in position. short and blunt). Anthers are dithecous, Corolla: Petals 5, white or blue basifixed and dehiscing longitudinally. apopetalous, irregular papilionaceous Gynoecium: Monocarpellary, corolla showing descendingly imbricate unilocular, ovary superior, with two aestivation. alternating rows of ovules on marginal Androecium: Stamens 10, diadelphous placentation. Style simple and bent, stigma (9)+1 nine stamens fused to form a bundle flattened or feathery. and the tenth stamen is free. Anthers

187

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 187 02-06-2018 15:04:31 Downloaded from https:// www.studiestoday.com

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 https://www.studiestoday.comStipe Gynoecium C.S.of Ovary

Floral formula

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

188

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 188 02-06-2018 15:04:32 Downloaded from https:// www.studiestoday.com

are dithecous, basifixed, introse and a posterior standard, two lateral wings, dechiscing by longitudinal slits. two anterior ones forming a keel which Gynoecium: Monocarpellary, uni- encloses stamen and pistil, vexillary / locular, with many ovules on mariginal descendingly imbricate aestivation. ­placentation, ovary superior, style simple Androecium: Stamens 10, diadelphous and incurved with feathery stigma. (9)+1 nine stamens fused to form a bundle Fruit: Legume and the tenth one is posterior and free. Seed: Non-endospermous, reniform. Anthers dithecous, basifixed, introse and dehisce longitudinally. Floral Formula: Dt0.Dtn0.'.""."M*7+.E7.C*;+-3.I3 Gynoecium: Monocarpellary, ovary Botanical description of Pisum sativum superior, unilocular, with many ovules on (Pea Plant) marginal placentation, style simple and Habit: Cultivated herb, becoming shrubby. curved, stigma capitate. Root: Branched tap root system, Fruit: Legume nodulated due to the presence of Seed: non-endospermous with thick nitrogen fixing bacteria (Rhizobium cotyledons.

leguminosorum). Floral Formula: Dt0.Dtn0.'.""."M*7+.E7.C*;+-3.I3 Stem: Erect and climbing, one to three feet high, young stem densely pubescent, somewhat angular, herbaceous, green and branched. Leaves: Alternate, petiolate, stipulate, stipules ¼ to ½ inch long attached near the base, compound (trifoliate), leaflets dark green, entire, acuminate, pubescent on both the sides, reticulate venation. Inflorescence: Clustered axillary Arachis hypogea Crotalaria verrucosa racemes. Flower: Bracteate (small and deciduous), bracteolate (usually persistent), pedicellate, heterochlamydeous, complete, bisexual, pentamerous,https://www.studiestoday.com zygomorphic and hypogynous. Calyx: Sepals 5, green synsepalous, companulate, showing valvate aestivation. Odd sepal is anterior in position. Indigofera tinctoria Aeschynomene aspera Corolla: Petals 5, apopetalous, Figure 5.14: Selected plants belongs to irregular papillionaceous, consisting of the Family Fabaceae

189

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 189 02-06-2018 15:04:34 Downloaded from https:// www.studiestoday.com

Tendril

Standard petal Flower Stigma Stamen Style

Ovary

Calyx Stipe Habit L.S.of flower

Standard Anther petal Filament Sepal Wing petal Single stamen

Keel petal

Calyx Corolla Androecium

Stigma

Style

Ovary Ovule Stipe Locule Gynoecium https://www.studiestoday.comC.S.of Ovary

Floral formula Br.,Brl.,%, , K ,C ,A ,G (5) 5 (9)+1 1 Floral diagram Figure 5.15: Pisum sativum

190

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 190 02-06-2018 15:04:35 Downloaded from https:// www.studiestoday.com

Economic Importance

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 https://www.studiestoday.com(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 191

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 191 02-06-2018 15:04:35 Downloaded from https:// www.studiestoday.com

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.

Clitoria ternatea Flowers Blue dye is obtained and seeds Butea monosperma Flowers Natural dye 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. https://www.studiestoday.com INTERNATIONAL YEAR OF PULSES

The Food and Agriculture Organization The attractive seeds of Adenanthera (FAO) of the United Nations has been pavonina (Family: Caesalpiniaceae) 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.

192 Downloaded from https:// www.studiestoday.com

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 192 02-06-2018 15:04:36 Downloaded from https:// www.studiestoday.com

5.13.2 Family: Apocynaceae (milk weed family) (including Asclepiadaceae) Systematic position Bentham and Hooker APG classification classification Kingdom Plantae Kingdom Plantae Clade Angiosperms Class Dicotyledonae Clade Eudicots Sub-class Gamopetalae Clade Asterides Series Bicarpellatae Order Order Gentianales Family Apocynaceae Family Apocynaceae

Diagnostic features reduced, exstipulate, opposite decusate • Plants with milky sap. (Calotropis) or sometimes alternate • Leaves opposite or whorled, exstipulate. (Thevetia) or in whorls of 3 (Nerium), • Flowers pentamerous. entire, rarely stipulate (Tabernaemontana). • Stamens epipetalous, connate with Inflorescence: A Panicle, dichasial corona. cyme, often umbelliform in (Asclepiadoids) • Fruit a follicle. or raceme, or axillary cluster of two • Stigma is thick and massive often flowers each (Catharanthus). connate to stamen to form Gynostegium Flowers: Bracteate, bracteolate, pedicel- • Seeds often with coma (hair). late, complete, bisexual, actinomorphic, zy- • Presence of nectariferous disc. gomorphic in Ceropegia heterochlamydeous , General Characters pentamerous, hypogynous but rarely perigy- nous or epigynous (Plumeria) Distribution: This family is represented by 345 genera, 4,675 species. Mostly tropical and subtropical whereas a few species found in temperate region. Habit: Tree (Alstonia), shrub, (Nerium), herb (Catharanthus), woody twiner (Allamanda, Succulent, Adenium usually twining shrubs with milky sap in https://www.studiestoday.comCeropegia spp laticiferous vessels. Root: Branched tap root system Calyx: Sepals 5, synsepalous (at least basally) sometimes aposepalous (Catharanthus) deeply Stem: The stems are succulent in some lobed ; valvate or quincuncial (Thevetia), taxa (Stapelia, caralluma), usually erect, odd sepal posterior, glandular appendages branched solid, glabrous, rarely tube like (Squamellae) present on the adaxial side. and thick. Corolla: Petals 5, sympetalous united Leaves: Simple, undivided, sometimes

193

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 193 02-06-2018 15:04:40 Downloaded from https:// www.studiestoday.com

into a tube, salver or funnel shaped; twisted Seed: Seeds are endospermous often with or rarely valvate, often hairy within or crown of hairs. contain some corona like out growths at Botanical description of Catharanthus the mouth of the corolla tube. roseus Androecium: Stamens 5 , alternipetalous, Habit: Erect ever blooming ornamental often epipetalous, apostemonous to plant with milky latex. monadelphous, In Asclepiadoids the stamens are connate to the styles to form a Root: Branched tap root system gynostegium, pollen grains of each theca of Stem: Aerial, erect, cylindrical reddish an anther are fused into a waxy mass called green, glabrous and branched. pollinium. The right pollinium of each anther Leaves: Usually simple, opposite attached to the left pollinium of the adjacent decussate, exstipulate, subsessile, anther by a hair like translator, translator arms or petiolate, elliptic – ovate, entire, (retinacula) attached together with the gland mucronate, unicostate reticulate venation. like structure called corpusculum. Anthers Inflorescence: cymose, axillary pairs. are dithecous, basifixed, often sagitate, introse; Flower: Ebracteate, Ebracteolate, dehisce longitudinally, anthers basally awned; subsessile, complete, bisexual, sometimes bear hairy appendages over the heterochlamydeous, actinomorphic, lobes (Nerium). hypogynous, pentamerous, rosy purple, Gynoecium: Bicarpellary, carpels apically white or pink. united, superior, or rarely half inferior Calyx: Sepals 5, slightly synsepalous, (Plumeria) 1 to 2 locule with 2 to many ovules green showing valvate aestivation. in each locule on marginal placentation. Style one and simple, stigma is characteristically Corolla: Petals 5, sympetalous, throat thickened, massive and bilobed. A of corolla tube hairy forming a corona, nectariferous disc is often present around twisted (hypocrateriform). or at the base of the gynoecium, (Thevetia, Androecium: Stamens 5, Catharanthus, Allamanda and Rauvolfia). apostemanous, epipetalous, inserted at the mouth of the corolla tube, filaments short, anthers sagittate, dithecous, dorsifixed, introse. Gynoecium: Bicarpellary, apocarpous, ovaries superior, unilocular, ovules many, https://www.studiestoday.complacentation marginal, style simple, stigma hour-glass shaped. Two scaly nectaries are present one on the anterior and another on the posterior side of the ovary. Fruit: The fruit is variable and can be a Fruit: A pair of elongated follicles. berry (Landolphia), drupe (Cerbera) follicle Floral Formula: Ebr.,Ebrl., , ,K (5),C(5),A5,G(2) (Asclepias), capsule (Allamanda).

194

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 194 02-06-2018 15:04:41 Downloaded from https:// www.studiestoday.com

Flower

Leaf

Fruit

Corolla

Sepal

Calyx Habit Flower entire Calyx Corolla Stigma (hour - glass shaped) Epipetalous stamens Style Stigma Style Ovary Ovary Scaly nectary L.S. of the flower Gynoecium

Scaly A pair of nectary elongated Ovule follicles Apocarpous ovary C.S. of thehttps://www.studiestoday.com ovary Fruit Seed Floral diagram Floral formula

Ebr.,Ebrl., , ,K(5),C(5),A5,G2 FigureFigure 5.51 5.16: CatharanthusCatharanthus roseus roseus

195

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 195 02-06-2018 15:04:41 Downloaded from https:// www.studiestoday.com

https://www.studiestoday.com

Figure 5.17: Calotropis gigantea

196

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 196 02-06-2018 15:04:41 Downloaded from https:// www.studiestoday.com

Economic importance of the family Apocynaceae

Economic S.No Binomial Useful part Uses importance

1 Food plant Carissa carandas (பெ쏁ம்ளா) Fruits Edible and used in pickles Carissa spinarum (殿쟁களா) 2 Medicinal Rauvolfia serpentina Shoot To treat hypertension plant (Indian snake root / and mental disorders sarpagandha) Dried roots Alkaloid (reserpine) obtained from the dried roots, of the plant can lower the blood pressure and used as sedative for patients suffering from Schizophrenia. Thevetia peruviana Seeds Used in rheumatism (lucky nut/ தங்அல쎿) Vallaris solanacea Latex Useful in toothache and to treat inflated gums.

Cerbera odollam Latex Used as an emetic and purgative.

Alstonia scholaris Bark Used in malaria and dysentery.

Strophanthus hispidus Seeds Yield the drug strophanthin

Wrightia tomentosa (பாலை) Bark and Used as antidote to Roots snakebite. Catharanthus roseus Aerial Used to treat muscle parts pain, the alkaloids like https://www.studiestoday.comvinblastine and vincris- tine are mainly used to treat various human cancers. Caralluma umbellate Succulent Antiobesity (க쾿믁쾿யான்) stem

197

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 197 02-06-2018 15:04:42 Downloaded from https:// www.studiestoday.com

3. Dye yielding Wrightia tinctoria Seeds An indigo- like dye plant is obtained from the seeds. 4. Ornamental Allamanda nerifolia (golden plant Grown as ornamentals plants trumpet), plants. Alstonia scholaris, Beaumontia grandiflora, Catharanthus roseus, Nerium indicum Plumeria obtusa, Plumeria alba, Stapelia spp, Hoya, Asclepias, and Cryptostegia.

Thevetia Plumeria

https://www.studiestoday.com

Rauvolfia Tabernaemontana Figure 5.18: Selected plants belongs to the family Apocynaceae

198

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 198 02-06-2018 15:04:47 Downloaded from https:// www.studiestoday.com

5.13.3 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 Stem: Herbaceous or woody; erect or • Leaves alternate, exstipulate. twining, or creeping; sometimes modified • Flowers actinomorphic, pentamerous. into tubers (Solanum tuberosum) often with bicollateral vascular bundles. • Calyx often persistence / accrescent. Leaves: Alternate, simple, rarely • Stamens 5, epipetalous, poricidal in pinnately compound(Solanum tuberosum dehiscence. and (Lycopersicon esculentum) exstipulate, • Carpels 2, ovary superior, 2 chambered, opposite or sub-opposite in upper part, obliquely placed, falsely four chambered unicostate reticulate venation. placenta swollen, ovule numerous. Inflorescence: Generally axillary or • Fruits berry or capsule, vascular terminal cymose (Solanum) or solitary bundles with both outer and inner flowers (Datura stramonium). Extra phloem (Bicollateral vascular bundle). axillary scorpiod cyme called rhiphidium General Characters (Solanum nigrum) solitary and axillary (Datura and Nicotiana) umbellate cyme Distribution: (Withania somnifera). Family Solanaceae includes about 88 Flowers: Bracteate (Petunia), or genera and about 2650 species, of these ebracteate (Withania) pedicellate, bisexual, Solanum is the largest genus of the heterochlamydeous, actinomorphic or family with about 1500 species. Plants weakly zygomorphic due to oblique position are worldwide in distribution but more https://www.studiestoday.comof ovary pentamerous, hypogynous. abundant in South America. Habit: Mostly annual herbs, shrubs, Calyx: Sepals 5, rarely 4 or 6, Synsepalous, small trees (Solanum violaceum) valvale peristaent, often accrescent with prickles (Solanum trilobatum), (enlarging to envelop the fruit) occasionally many with stellate trichomes; rarely vines enclosing the fruit ( Physalis, Withania) (Lycium sinensis) Corolla: Petals 5, sympetalous, rotate, Root: Branched tap root system. tubular (Solanum) or bell- shaped (Atropa)

199

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 199 02-06-2018 15:04:48 Downloaded from https:// www.studiestoday.com

or infundibuliform (Petunia) usually showing twisted aestivation, funnel alternate with sepals; rarely bilipped shaped with wide mouth and 10 lobed. and zygomorphic (Schizanthus) usually Androecium: Stamens 5, free from valvate, sometimes convolute (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(others 3 are dithecous, with long filament, introse and reduced to staminode), 4 and didynamous longitudinally dehiscent. in (Salpiglossis) Anthers dithecous, dehisce Gynoecium: Ovary bicarpellary, longitudinally or poricidal. syncarpous superior ovary, basically Gynoecium: Bicarpellary, syncarpous biloculear but tetralocular due to the obliquely placed, ovary superior, bilocular formation of false septum. Carpels are but looks tetralocular due to the formation obliquely placed and ovules on swollen of false septa, numerous ovules in each axile placentation. Style simple long and locule on axile placentation. filiform, stigma two lobed. Fruit: Spinescent capsule opening by Fruit: A capsule or berry. In four apical valves with persistent calyx. Lycopersicon esculentum, Capsicum, the fruit is a berry and in species of Datura Seed: Endospermous. Dt0.Gdtn0.""".""".M .E .C .I and Petunia, the fruit is a capsule. Floral Formula: *7+ *7+ 7 *4+ Seed: Endospermous.

Botanical description of Datura metel Habit: Large, erect and stout herb. Root: Branched tap root system. Stem: Stem is hollow, green and herbaceous with strong odour. Leaf: Simple, alternate, petiolate, entire Solanum trilobatum Atropa belladonna or deeply lobed, glabrous exstipulate showing unicostate reticulate venation. Inflorescence: Solitary and axillary cyme. Flower: Flowers are large, greenish white, bracteate,https://www.studiestoday.com ebracteolate, pedicellate, complete, heterochlamydeous, pentamerous, regular, actinomorphic, bisexual and hypogynous. Calyx: Sepals 5, green synsepalous showing valvate aestivation. Calyx is mostly Withania somnifera Schizanthus pinnatus persistant, odd sepal is posterior in position. Corolla: petals 5, greenish white, Figure 5.19: Selected plants belongs to sympetalous, plicate (folded like a fan) the Family Solanace

200

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 200 02-06-2018 15:04:49 Downloaded from https:// www.studiestoday.com

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 capsulehttps://www.studiestoday.comdehiscence Floral formula Floral Diagram Br.,Ebrl., , ,K(5),C(5),A5,G(2) Figure 5.20: Datura metel

201

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 201 02-06-2018 15:04:50 Downloaded from https:// www.studiestoday.com

Botanical description of Solanum americanum

Corolla Stamen Fruit

Extra - Axillary Inflorescence Corolla scorpioid cyme Stamen

Habit 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 Fruithttps://www.studiestoday.comC.S.of ovary

Floral formula

Ebr.,Ebrl., , ,K(5),C(5),A5,G(2) Floral diagram

Figure 5.58 Solanum nigrum Figure 5.21: Solanum americanum

202

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 202 02-06-2018 15:04:50 Downloaded from https:// www.studiestoday.com

Habit: A small annual herb Calyx: Sepals 5, synsepalous, green, Root: Branched tap root system. persistent and showing valvate aestivation. Stem: Aerial, erect, green and Corolla: petals 5, sympetalous, white, herbaceous showing valvate aestivation. Leaf: Simple, alternate but opposite Androecium: Stamens 5, in the floral region, petiolate, exstipulate apostamenous, epipetalous, filaments ovate, entire or slightly lobed, acute short, anthers conniving and forming unicostate reticulate venation. an envelope around the style dithecous, Inflorescence: Extra-axillary (due to basifixed with apical pores. fusion of floral axis) scorpioid cyme called Gynoecium: Bicarpellary, syncarpous, rhiphidium superior, bilocular, many ovules in each Flower: Ebracteate, pedicellate, locule on axile placentation, septum white, bisexual, actinomorphic, oblique, highly swollen placenta, style heterochlamydeous, pentamerous, long and hairy at the base, stigma bifid. hypogynous white. Fruit: Berry

Floral Formula: Ebr.,Ebrl., , ,K(5),C(5),A5,G(2)

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 https://www.studiestoday.com 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)

203

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 203 02-06-2018 15:04:50 Downloaded from https:// www.studiestoday.com

Economic importance of the family solanaceae S.No Economic Binomial Useful part Uses importance 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) 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 https://www.studiestoday.comPetunia hybrida, Schizanthus pinnatus Brugmansia species (Angel trumpet) Solanum betaceum (Tree tomato)

204

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 204 02-06-2018 15:04:51 Downloaded from https:// www.studiestoday.com

5.13.4 Family: Euphorbiaceae (Castor Family / Spurge Family )

(In APG classification Peraceae, Phyllanthaceae and Picrodendraceae are excluded from the family Euphorbiaceae) Systematic position Bentham and Hooker APG Classification Classification

Kingdom Plantae Kingdom Plantae

Clade: Angiosperms Class: Dicotyledonae Clade: Eudicots Sub-class: Monochlamydeae Clade: Rosids Series: Unisexuales Order: Order: Euphorbiales Family: Euphorbiaceae Family: Euphorbiaceae

Diagnostic features Root: Well branched tap root system. • Latex is present either milky or watery. Stem: Aerial, erect or prostrate • Inflorescence generally cymose, catkin in (E.prostrata), herbaceous or woody. Stem , cyathium in sp. becomes modified into flattened, leaf- like and becomes succulent in several • Flowers apetalous, unisexual. species of Euphorbia. Such modified • Ovary tricarpellary, distinctly trilobed. stem is called phylloclades. Cylindrical, • Fruit capsule or regma. branched, solid or hollow, usually contain latex either milky (E.tirucalli) or watery General characters (Jatropha curcas). Distribution: Euphorbiaceae includes Leaf: Stipulate or exstipulate. 214 genera and about 5600 species. The Mostly simple, alternate, often reduced plants of this family are found throughout or deciduous as in several species of the world. Well represented in Africa and Euphorbia, palmately lobed in Ricinus South America.https://www.studiestoday.com or deeply lobed in Manihot. The stiplues Habit: Mostly shrubs (Ricinus are modified into a pair of spines communics, Jatropha gossypifolia) or tree (E.splendens) or glandular hairs (Jatropha Emblica officinalis, herbs (Phyllanthus curcas ). The leaves around the cyathium amarus) , twiners ( involucrata) inflorescence become beautifully coloured some are xerophytic (Euphorbia) with in E.pulcherrima (Paalperukki tree) with cactus – like (phylloclades) plants usually unicostate or multicostate reticulate contain milky or watery sap.

205

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 205 02-06-2018 15:04:51 Downloaded from https:// www.studiestoday.com

venation. Androecium: The number of stamens Inflorescence: The inflorescence of vary from 1 to many. In Euphorbia a Euphorbiaceae varies greatly, Terminal single stalked stamen represents a single raceme – , Ricinus, male flower. In Ricinus usually 5 stamens Catkin – Acalypha hispida Cyme - are present, but each stamen is profusely Jatropha, solitary axillary – Phyllanthus branched. In Jatropha they are arranged in asperulatus, cyathium – Euphobia two whorls each of 5 stamens. The stamens species. are indefinite (Crotons), the filaments may be free or connate. The anthers are Cyathium is the an unique and special dithecous, dehisce either by apical or by inflorescence of this family. Each cyathium transverse or longitudinal slits. contains centrally a single, naked terminal female flower, usually represented by a Gynoecium: Tricarpellary, rarely tricarpellary gynoecium. The female flower bicarpellary (Bridelia, Mercurialis), tetra is surrounded by a cup-like involucre or pentacarpellary formed by 4 or 5 connate sepaloid bracts. (Wielandia), syncarpous, ovary In the axil of each bract develops a group of superior, rarely semi-inferior, ovules one stamens in a scorpioid manner. Each stamen or two in each locule on axile placentation, represents a naked male flower because it is rarely locule splits into two forming six a jointed structure, its upper portion is the chambers (Phyllanthus). Styles 3, each filament bearing the anther and its lower split into two feathery stigma. Nectaries portion represents the pedicel of the male are usually present, gynoecium is present flower bearing stamen. A nectar secreting as a pistillode in staminate flowers. gland is present on the rim of the involucre. Fruit: Fruits are capsule or schizocarp. Glands are oval or crescent shaped and It breaks violently and dehisce into three often brightly coloured. Though cyathium one seeded cocci called regma (Ricinus ), appears like a single flower, it actually drupe in Emblica officinalis and berry or an inflorescence. samara. Flowers: Flowers are always unisexual, Seed: Seeds are endospermous. In and are highly variable. Bracteate, Ricinus knob-like caruncle develops from ebracteolate, generally unisexual, the micorpyle,that absorbs and temporarily homochlamydeous, rarely retains water enabling germination. heterochlamydeous, monoecious (Baliospermum) or dioecious (Bridelia), actinomorphic,https://www.studiestoday.com rarely zygomorphic, hypogynous, rearly perigynous (Bridelia). Perianth: Tepals 0 to 5 biseriate (male flowers of Croton bonplandianum) uniseriate or aphyllous (Euphorbia), valvate or imbricate when present, apophyllous or synphyllous. Ricinus

206

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 206 02-06-2018 15:04:52 Downloaded from https:// www.studiestoday.com

Botanical Description Of Ricinus communis (Castor) Female flower Male flower

Stigma Stigma Habit Style Style Ovary Ovule Perianth Ovule Ovary

Female flower C.S.of Ovary L.S.of female flower Crowded and connate stamen Stamen Stipitate phalanges Perianth Anther Branched filament Filament

Male flower Polyadelphous stamens Stamen

Floral formula of male flower Br.,Ebrl., , ,P ,A ,G https://www.studiestoday.com(5) 0 Floral formula of female flower

Br.,Ebrl., , ,P(3),A 0,G(3)

Floral diagram of male flower Floral diagram of female flower FigureFigure 5.64 5.22: Ricinus Ricinus communis communis

207

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 207 02-06-2018 15:04:53 Downloaded from https:// www.studiestoday.com

Habit: Tall perennial shrub pedicellate, female flowers (open for Root: Branched tap root system fourteen days) found towards the apical Stem: Aerial, erect, cylindrical, branched portion of inflorescence, actinomorphic, and hollow, solid at the base, glabrous, incomplete and hypogynous. Leaf: Simple, petiolate, hollow, exstipulate, Perianth: Tepals 3, apophyllous, green alternate, broad, palmately lobed, usually 7-9 valvate. lobes, serrate, palmately reticulate divergent Androecium: Absent but staminode is venation. present. Inflorescence: Terminal panicle. Gynoecium: Tricarpellary, syncarpous, Male Flower Bracteate, ebracteolate, ovary superior, distinctly trilobed, trilocular, pedicellate, male flowers (open for one day) covered with spiny outgrowth, single large towards lower portion of the inflorescence, ovule in each locule on axile placentation, actinomorphic, incomplete. style three with three bifid stigma. Perianth: Tepals 5, apophyllous, Fruit: A schizocarp with spiny uniseriate, green, valvate aestivation, odd outgrowth, splits into three one seeded tepal posterior in position. cocci. Androecium: Stamens numerous (upto Seed: Endospermous, knob-like 1000) crowded and connate into about 8mm caruncle develops from the micorpyle, long cluster of stipitate phalanges, each stamen that absorbs and temporarily retains water profusely branded, anthers globose basifixed. enabling germination. Gynocium: usually absent rarely Floral Formula:

represented by pistillode. Male flower: Br.,Ebrl., , ,P(5),A ,G0

Female Flower Bracteate, ebracteolate, Female flower: Br.,Ebrl., , ,P(3),A 0,G(3)

https://www.studiestoday.comHevea brasiliensis Euphorbia pulcherrima

Euphorbia splendens Croton tiglium Figure 5.23: Selected plants belongs to the Family Euphorbiaceae 208

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 208 02-06-2018 15:05:00 Downloaded from https:// www.studiestoday.com

Economic importance of the family Euphorbiaceae Economic Binomial Useful part Uses importance Food plant Emblica officinalis (Nellikai) Fruits Rich in vitamin C, which P. acidus (அரைநெ쯍쮿) are edible and pickled. Manihot esculenta (Maravalli Tuberous Roots are rich in starch kizhanku / Tapioca) roots and used for preparing bread, biscuits, chips and other food stuffs. Sauropus androgynous Leaves Greens (multi vitamin plant)

Oil plant Croton oil Croton tiglium Seed Used as a powerful purgative and also to treat skin diseases.

Castor Oil Ricinus communis Seeds Used as vegetable oil, (Amanakku/Castor) ricinoleic acid present in this oil eliminate acne causing bacteria apart from that it acts as laxative and lubricant. Jatropha Oil Jatropha curcas (Kattamanakku) Seeds Used for biofuels.

Rubber: Hevea brasiliensis Coagulated Latex is used in rubber (Para rubber) latex products like tube and Manihot glaziovii (Manicoba rubber) tyre. Medicinal Euphorbia resinifera Latex Euphorbium drug is plants obtained from the latex and used as a purgative. Euphorbia hirta Whole plant Lactogogue https://www.studiestoday.com(அம்மꟍ பச்쎿殿) Mallotus philippenensis Fruits Used as anthelmintic. Phyllanthus amarus (Keezhanelli) Entire shoot Used to treat Jaundice. system

209

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 209 02-06-2018 15:05:00 Downloaded from https:// www.studiestoday.com

Economic Binomial Useful part Uses importance Jatropha gossypifolia Leaves and Used in the treatment of roots leprosy and snakebite. Croton tiglium (நேர்வள믍) Seed Purgative Ricinus communis Seed oil Purgative Dye yielding plants Kamela dye, Mallotus philippenensis Fruits Used for dyeing wool and silk. Blue dye Jatropha curcas Bark Used for dyeing clothes and fishing nets. Purple dye tinctoria Bark Used in textile Industry Red dye Phyllanthus reticulatus Roots Used for tanning and dyeing fishing lines and nets Timber plant dioica, Timber Used for packing cases, Bischofia javanica, tea boxes, veneers, (ர�ோமힿ쏁ட்믍) plywood, match industry Drypetes roxburghii (ퟀரைமர믍) and several other similar purpose. Ornamental Acalypha ciliata, Plants Grown as ornamental plant A. hispida, plants. Codiaeum varigatum Croton tiglium Euphorbia antiquorum, E.pulcherrima, E.splendens. E. tirucalli Jatropha gossypifolia

5.13.5 Family Musaceae – Banana Family Diagnostichttps://www.studiestoday.com Features • Perennial giant herbs with pseudostems • Corolla 2 lipped. formed by leaf sheaths. • Ovary tricarpellary, inferior. • Leaves are large with thick midrib, • Fruit elongated berry. parallel venation. • Septal nectaries are present. • Flowers are zygomorphic, unisexual, inflorescence spadix covered by spathe.

210

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 210 02-06-2018 15:05:00 Downloaded from https:// www.studiestoday.com

Systematic Position Bentham and Hooker APG Classification Classification Kingdom Plantae Kingdom Plantae Clade Angiosperms Class: Monocotyledonae Clade Monocots Subclass Zingiberidae Clade Commelinids Series Epigynae Order Order Zingiberales Family Musaceae Family Musaceae Musa velutina

Marantaceae

Cannaceae Zingiberaceae

Costaceae Heliconiaceae

Strelitziaceae

Lowiaceae Musaceae

Rhizogram of the Zingiberales

Note: Earlier Musaceae was a large family with 6 genera viz. Musa, Ensete, Ravenala, Strelitzia, and . In APG only Musa and Ensete are retained while Ravenala, Strelitzia, Orchidantha and Heleconia are separated. General https://www.studiestoday.comCharacters Habit: Large perennial herbs Distribution perennating by means of rhizome ( Musa paradisiaca), raraly trees as in Ravenala Musaceae includes only 2 genera (Musa madagascariensis. and Ensete) and 81 species. The members of this family are mainly wet tropical Root: Fibrous adventitious root lowlands from West Africa to Pacific system. (southern Japan to Queensland). (Musa Stem: In Musa the real stem is is the most common plant of the family found underground called rhizomatous found in India) (dichotomously branching in atleast

211 Downloaded from https:// www.studiestoday.com

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 211 02-06-2018 15:05:01 Downloaded from https:// www.studiestoday.com

some spp). The apparent aerial erect, most of the species of Musa, the three unbranched tall pseudostem is formed by outer tepals and two lateral tepals of the the long stiff and sheathy leaf bases which inner whorl are fused to form 5 toothed are rolled around one another to form an tube like structure called abaxial lip. The aerial pseudostem. The central axis that is posterior inner median tepal alone is free, concealed at the bottom of the pseudostem which is distinctly broad and membranous in called shaft, which elongates and pierces called labellum. through the pseudostem at the time of Androecium: Stamens 5 or 6, flowering and produces inflorescence arranged in two whorls of 3 each opposite terminally. monocorpic in Musa. and adnate to the tepals. In Musa only 5 (produces flowers and fruits once during stamens are fertile and the inner posterior its life time). Stem is aerial and woody in stamen is either absent or represented by a Ravenala madagascariensis. staminode. In Ravenala all the six stamens Leaf: Simple with long and strong are fertile. Filaments free, anthers linear, petiole the leaf blade is large and broad dithecous dehisce by longitudinal slits, with sheathy leaf base. The leaf is and with sticky pollen. exstipulate. Oval, obtuse or oblong with Gynoecium: Tricarpallary, syncarpous, a stout midrib, entire, numerous parallel the median carpel is anterior in position, veins extending up to the margin, rolled trilocular ovary inferior, ovules many, in bud . Phyllotaxy is spiral in Musa placentation axile, style filiform, stigma and distichous i.e. leaves are arranged three lobed septal nectaries are present. alternately in two opposite vertical rows Fruit: Elongated berry containing in Ravenala. numerous seeds, fruits forming compact Inflorescence: Terminal or axillary bunches, seeds with copious and small thyrse of one to many monochasial embryo in Musa. Capsule in Ravenala. branched spadix in Musa, Usually the Seed: Starch rich endosperm and flowers are protected by large brightly starchless perisperm. Species of Ensete are coloured, spirally arranged, boat shaped distinguished from those of Musa by their bract called spathe. Compound cyme in larger seeds. Ravenala. Flowers: Bracteate, ebracteolate, Botanical Description of Musa sessile, trimerours, unisexual, or bisexual paradisiaca. or polygamous, when unisexual the Habit: Monocarpic gigantic herb. flowers https://www.studiestoday.comare monoecious. Flowers are Root: Fibrous adventitious root zygyomorphic and epigynous. (In Musa system. flowers are polygamous i.e. staminate Stem: The real stem is underground flowers, pistilate flowers and bisexual called rhizomatous. The apparent, aerial flowers are present in the same plant). erect unbranched pseudo stem is formed Perianth: Tepals 6, biseriate, by the long, stiff and sheathy leaf bases arranged in two whorls of 3 each and which are rolled around one another to homochlamydeous, 3 +3 syntepalous. In form an aerial pseudostem. The central

212

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 212 02-06-2018 15:05:01 Downloaded from https:// www.studiestoday.com

Leaf Spathe

Flower Fruit

Branched spadix Inflorescence Spathe with flowers Outer tepal Pseudo Inner tepal Abaxial lip stem Stigma Anther

Labellum

Habit Ovary Fused tepals Labellum Bisexual flower

Anther Stigma Filament Style

Stamens

Locule Ovary Floral diagram Ovule https://www.studiestoday.comAnterior median Floral formula : Bisexual flower carpel Br.,Ebrl.,%, , P(3+2)+1,A3+3,G(3) C.S of ovary Gynoecium

FigureFigure 5.68 5.24: Musa Musa paradisiacaparadisiaca

213

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 213 02-06-2018 15:05:02 Downloaded from https:// www.studiestoday.com

axis that is concealed at the bottom of Androecium: Stamens 6, arranged in the pseudostem is called shaft. The shaft two whorls of 3 each, arranged opposite to elongates, pierces through the pseudostem the tepals. Only five stamens are fertile and and produces an inflorescence terminally. the inner posterior stamen is either absent Leaf: Simple with a long and strong or represented by staminode. Anthers are petiole. The leaf blade is large and broad dithecous and they dehisce by vertical with sheathy leaf base. Leaf exstipulate and slits. Filament is simple and filiform and obtuse pinnately parallel venation which rudimentary ovary or pistillode is often extends upto the leaf margin phyllotaxy is present in the male flower. spiral. Gynoecium: Tricarpellary, syncarpous, Inflorescence: Terminal branched the median carpel anterior, trilocular, spadix. Flowers are protected by large, ovary inferior, numerous ovules on axile brightly coloured spirally arranged, boat placentation. Style is simple and filiform, shaped bracts called spathe. When the stigma trilobed. Septal nectaries are flowers open, spathe rolls back and falls off. present. Flower: Bracteate, ebracteolate, sessile, Fruit: An elongated fleshy berry and trimerous, unisexual or bisexual, flowers seeds are not produced in cultivated are zygomorphic and epigynous. varieties. Perianth: Tepals 6, biseriate, 3+3 Floral Formula syntepalous, arranged in two whorls of Male flower:

3 each and homochlamydeous, the three Br,Ebrl,%, ,P(3+2)+1,A3+3,G0. tepals of the outer whorl and the two lateral Female flower: tepals of the inner whol are fused by valvate Br,Ebrl,%, ,P ,A ,G . aestivation to form 5 toothed tube like (3+2)+1 0 (3) structure called abaxial lip, the posterior Bisexual flower: inner median tepal is distinctly broad Br,Ebrl,%, ,P(3+2)+1,A3+3,G(3). membrancus and free called labellum.

https://www.studiestoday.com

Ensete ventricosum Ravenala Strelitzia reginae Heliconia spp madagascariensis Figure 5.25: Selected plants belongs to the Family Musaceae

214

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 214 02-06-2018 15:05:10 Downloaded from https:// www.studiestoday.com

Economic Importance of The Family Musaceae S.No Economic Binomial Useful part Uses importance 1 Food plant Musa paradisiaca. The raw (tender Cooked and eaten green) bananas, the as vegetable. shaft and male buds. Leaves Commonly used as plates on festive occasions and are widely used to wrap food items Fruit when cooking. Crunchy and salty fried plantain chips are delicious. Flower stalk (Shaft) Edible after Ensete ventricosa cooking. Fruits Edible bananas Musa chinensis which are sweet, (Chinea kela) rich in starch and vitamins. 2. Medicinal Musa spp. Sap obtained from Considered to be plant the sheathy leaf an antidote for base. cobra bite. 3. Starch Ensete ventricosum The swollen basal Used as a source (Ethiopean banana) parts of leaf sheaths of starch and vitamins. 4. Fibre yielding Musa textilis Fibre Fibre is woven and plant (Manila hemp) made into abaca cloth, also used for twine, bagging and https://www.studiestoday.comwrapping paper. 5. Ornamental Musa coccinea Plant Have ornamental plant (a wild banana species). scarlet flowers. (M. acuminata, M. Cultivated as velutina and M. ornata) ornamentals Ensete ventricosum

Continued

215

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 215 02-06-2018 15:05:10 Downloaded from https:// www.studiestoday.com

*Ravenala Plant madagascariensis (traveller’s palm), *Strelitzia reginae (bird of paradise ) and *Heliconia Grown as spp. ornamental plants

5.13.6 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 Note: Liliaceae of Bentham and • Perennial herbs often with bulbous Hooker included Allium, Gloriosa, stem / rhizomes. 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 Root: Adventitious and fibrous, and Distribution: Liliaceae are fairly large typically contractile. family comprising about 15 genera and 550 species. Members of this family are Stem: Stems usually bulbous, widely distributed over most part of the rhizomatous in some, aerial, erect world. (Dracaena) or climbing (Smilax) in https://www.studiestoday.comRuscus the ultimate branches are modified Habit: Mostly perennial herbs into phylloclades, In Asparagus stem is persisting by means of a sympodial modified into cladodes and the leaves are rhizome (Polygonatum), by a bulb reduced to scales. (Lilium) corm (Colchicum), shrubby or tree like (Yucca and Dracaena). Woody Leaf: Leaves are radical (Lilium) or climbers, climbing with the help of cauline (Dracaena), usually alternate, stipular tendrils in Smilax. Trees in opposite (Gloriosa), sometimes fleshy Xanthorrhoea, succulents in Aloe. and hollow, reduced to scales (Ruscus and Asparagus). The venation is parallel but

216

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 216 02-06-2018 15:05:10 Downloaded from https:// www.studiestoday.com

in species of Smilax it is reticulate. Leaves Fruit: Fruit usually a septicidal are usually exstipulate, but in Smilax, two or loculicidal capsule or a berry as in tendrils arise from the base of the leaf, Asparagus & Smilax. which are considered modified stipules. Botanical description of Allium cepa Inflorescence: Flowers are usually (In APG classification, Allium cepa is borne in simple or branched racemes placed under the family Amaryllidaceae) (Asphodelus) spikes in Aloe, huge terminal panicle in Yucca, solitary and axillary in Habit: Perennial herb with bulb. Gloriosa, solitary and terminal in Tulipa. Root: Fibrous adventitious root system Flowers: Flowers are often showy, Stem: Underground bulb pedicellate, bracteate, usually ebracteolate Leaf: a cluster of radical leaves emerges except Dianella and Lilium, bisexual, from the underground bulb, cylindrical actinomorphic, trimerous, hypogynous, and fleshy having sheathy leaf bases with rarely unisexual (Smilax) and are dioecious, parallel venation. rarely tetramerous (Maianthemum), slightly zygomorphic (Lilium) and hypogynous. Inflorescence: Scapigerous i.e. the inflorescence axis (peduncle) arising from Perianth: Tepals 6 biseriate arranged the ground bearing a cluster of flowers in two whorls of 3 each, apotepalous or at its apex. Pedicels are of equal length, rarely syntepalous as in Aloe. Usually arising from the apex of the peduncle petaloid or sometimes sepaloid, odd tepal which brings all flowers at the same level. of the outer whorl is anterior in position, valvate or imbricate, tepals more than six Flower: Small, white, bracteate, in Paris quadrifolia. ebrcteolate, pedicellate, complete, trimerous, actinomorphic and Androecium: Stamens 6, arranged hypogynous. Flowers are protandrous. in 2 whorls of 3 each: rarely stamens are 3 (Ruscus),4 in Maianthemum, or up to Perianth: Tepals 6, white,arranged 12, apostamenous, opposite to the tepals, in two whorls of three each, syntepalous sometimes epitepalous; filaments distinct showing valvate aestivation. or connate, anthers dithecous, basifixed Androecium: Stamens 6, arranged or versatile, extrose, or intrese, dehiscing in two whorls of three each, epitepalous, usually by vertical slit and sometimes apostamenous /free and opposite to tepals. by terminal pores; rarely synstamenous Anthers dithecous, basifixed, introse, and (Ruscus). dehiscing longitudinally. Gynoecium:https://www.studiestoday.com Tricarpallary, Gynoecium: Tricarpellary and syncarpous, the odd carpel usually syncarpous. Ovary superior, trilocular with anterior, ovary superior, trilocular, with two ovules in each locule on axile placentation. 2 rows of numerous ovules on axile Style simple, slender with simple stigma. placextation; rarely unilocular with Fruit: A loculicidal capsule. parietal placentation, style usually one; Seed: Endospermous stigmas 1 or 3; rarely the ovary is inferior Floral Formula: (Haemodorum), nectar – secreting septal Br.,Ebrl., , ,P +A ,G glands are present in the ovary. (3+3) 3+3 (3)

217

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 217 02-06-2018 15:05:10 Downloaded from https:// www.studiestoday.com

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 Pedicel L.s of flower Gynoecium C.S. of ovary

https://www.studiestoday.comFloral formula

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

Floral diagram Figure 5.26: Allium cepa

218 Downloaded from https:// www.studiestoday.com

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 218 02-06-2018 15:05:10 Downloaded from https:// www.studiestoday.com

Economic importance of the family liliaceae

S.No Economic 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 Used as vegetables. shoots 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. https://www.studiestoday.comSmilax glabra; and Roots Used in the treatment of S.ovalifolia; venereal diseases.

4. Fibre Phormium tenax Fibre Used for cordage, fishing yielding net, mattings, twines plant 5. Raticides Urginea indica Bulbs Used for killing rats Insecticides Veratrum album Bulbs Used as insecticide.

Continued 219

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 219 02-06-2018 15:05:10 Downloaded from https:// www.studiestoday.com

S.No Economic Binomial Useful part Uses importance 6. Polyploidy Colchicum luteum Corm Colchicine (alkaloid) used to induce polyploidy. 7. Ornamental Agapanthus Plant Some of the well known plants africanus garden ornamentals. (Africian Lilly) Hemerocallis fulva Can you identify (Orange Day Lilly) this? Gloriosa superba a. Name the family. (Malabar glory lilly) b. Write the binomial. Lilium candidum c. List the economic Lilium giganteum uses. 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 moth, Lilium nilgiriensis Smilax especially during nights. This moth https://www.studiestoday.comcollects a lot of pollen grains from one flower and visits another flower. Life history of this moth is intimately associated with Tulipa Ruscus the pollination mechanism in Yucca. Figure 5.27: Selected plants belongs to the Family Liliaceae

220

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 220 02-06-2018 15:05:14 Downloaded from https:// www.studiestoday.com

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, greenish yellow when bloom, turn flame red at the tips when matures

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.

Thehttps://www.studiestoday.com 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.

221

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 221 02-06-2018 15:05:14 Downloaded from https:// www.studiestoday.com

Summary fall in to three types; artificial, natural and Taxonomy deals with the identification, phylogenetic. Carolus Linnaeus outlined an naming and classification of plants. But artificial system of classification in “Species systematics deals with evolutionary Plantarum” in 1753. The first scheme of relationship between the organisms in classification based on overall similarities addition to taxonomy. Taxonomic hierarchy was presented by Antoine Laurent De Jessieu was introduced by Carolus Linnaeus. It also in 1789. A widely followed natural system includes ranks. Species is the fundamental of classification was proposed by George unit of taxonomic classification. Species Bentham (1800 - 1884) and Joseph Dalton concept can be classified into two groups Hooker. This system was not intended based on the process of evolution and to be phylogenetic. One of the earliest product of evolution. There are three phylogenetic systems of classification types of species, morphological, biological was jointly proposed by Adolf Engler and phylogenetic species. Type concept and Karl A Prantl in a monumental work emphasizes that a specimen must be “Die Naturelichen Pflanzen Familien”. associated with the scientific name which Arthur Cronquist proposed phylogenetic is known as nomenclatural type. There are classification of flowering plants based different types and they are holotype, isotype, on a wide range of taxonomic characters lectotype etc. Taxonomic aids are the tools including anatomical and phytochemical for the taxonomic study such as keys, flora, of phylogenetic importance in his book revisions, catalogues, botanical gardens and titled “The evolution and classification of herbaria. Botanical gardens serve different flowering plants.”Angiosperm phylogeny purposes. They have aesthetic value, offers group (APG) classification is the most scope for botanical research, conservation recent classification of flowering plants of rare species and propagation of many based on phylogenetic data. APG system species. Botanical survey of India explores is an evolving and currently accepted and documents biodiversity all over India. It system across the world and followed by has 11 regional centres in India. Herbarium all the leading taxonomic institutions and preparation includes plant collection, practising taxonomists. documentation of field data, preparation of Cladistics is the methodology, used plant specimens, mounting and labelling. to classify organisms into monophyletic There are several national and international groups, consisting of all the descents of herbaria. National herbaria include MH, the common ancestors. The outcome PCM, CALhttps://www.studiestoday.com etc. Kew herbarium is the world’s of a cladistic analysis is a cladogram largest one. and is constructed to represent the best Classification is the basis for cataloguing hypothesis of phylogenetic relationships. and retrieving information about the Chemotaxonomy is the scientific approach tremendous diversity of flora. It helps us of classification of plants on the basis of to know about different varieties, their their biochemical constituents in them. phylogenetic relationship and exact position. Utilization of the characters of chromosome Some important systems of classification are for the taxonomic inference is known

222

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 222 02-06-2018 15:05:14 Downloaded from https:// www.studiestoday.com

as karyotaxonomy. The application of c. Comparative cytology serology in solving taxonomic problems d. Evolutionary relationships is called serotaxonomy. Molecular 3. The taxonomy which involves the Taxonomy is the branch of phylogeny that similarities and dissimilarities among analyses hereditary molecular differences, the immune system of different taxa mainly in DNA nuclear and chloroplast is termed as sequences, to gain information and to a. Chemotaxonomy establish genetic relationship between the members of different taxonomic categories. b. Molecular systematics Different molecular markers like allozymes, c. Serotaxonomy mitochondrial DNA, microsatellites, d. Numerical taxonomy RAPDs, AFLPs, single nucleotide 4. Which of the following is a flowering polymorphism- SNP, microchips or arrays plant with nodules containing are used in analysis. Molecular Taxonomy filamentous nitrogen fixing micro - unlocks the treasure chest of information organisms? on evolutionary history of organisms.It a. Crotalaria juncea plays a vital role in phytogeography, which b. Cycas revoluta ultimately helps in genome mapping and biodiversity conservation. DNA barcoding c. Cicer arietinum is a taxonomic method that uses a very d. Casuarina equisetifolia short genetic sequence from a standard part 5. Flowers are zygomorphic in of a genome. It helps in identification of a. Ceropegia b. Thevetia organisms. c. Datura d. Solanum Evaluation 6. What is the role of national gardens in conserving biodiversity – discuss 1. Specimen derived from non-original 7. Where will you place the plants which collection serves as contain two cotyledons with cup the nomenclatural shaped thalamus? type, when original 8. How does molecular markers work specimen is missing. to unlock the evolutionary history of It is known as organisms? a. Holotype b. Neotype 9. Give the floral characters of Clitoria c. Isotypehttps://www.studiestoday.com d. Paratype ternatea. 2. Phylogenetic classification is the 10. How will you distinguish Solanaceae most favoured classification because members from Liliaceae members? it reflects a. Comparative Anatomy b. Number of flowers produced

223

TN_GOVT_BOTANY_LV_XI_Page 160-224 CH05.indd 223 02-06-2018 15:05:14