Introduction: Plants are included in Kingdom Plantae. These were classified into major groups, each with distinct characters.
(5.1) CLASSIFICATION OF PLANTS:
According to various systems, the classifications of plants are as given below-
(a) Artificial System: - In this system, plants were classified on the basis of one or few convenient superficial characters. Pliny the Elder (79, AD) first of all give artificial system of classification.
- Theophrastus proposed first a kind of artificial system of classification on the basis of habit of plants. He classified them as herbs, shrubs, under shrubs, trees etc.
- C. Linnaeus (1707-1778) used artificial system of classification based only upon floral parts. The plants were classified as Hypogyny, Perigyny and Epigyny. It is also known as Sexual / Numerical System of classification. Linnaeus also classified plants on the basis of number and position of stamens. Plants with one stamen belonged to class Monandria and with 20 or more stamens to class Icosandria.He divided plants into 24 classes. Out of these, 23 classes were of Flowering Plants and 24rth class was of Flowerless plant(Cryptogamia). He published papers like Flora Laponica, Species Plantarum, Critica Botanicaa and Systema Naturae.
This system was inadequate. So, classification according to it was not accepted.
(b) This system is more common and divides plant kingdom into two sub-kingdoms Cryptogamae and Phanerogamae.
Sub-kingdoms were named on the basis of presence or absence of seeds / flowers.
Cryptogamae –(kryptos-concealed gamos-marriage) These included all non-flowering plants without seeds like Algae, Fungi, Lichens, Mosses and Ferns.
Phanerogamae- (Phaneros- visible gamos-marriage) or Spermatophytes (sperma-seed-phyton-plant)-These included all flowering plants with seeds.
Phanerogams can be distinguished from Cryptogams by presence of well-developed vascular tissue for conduction of water, minerals (xylem) and food (phloem). Plants with their vascular tissues resembling trachea (wind pipe) of animals are called Tracheophytes.
(5.2) THALLOPHYTA- ALGAE
1 - It includes both, Algae and fungi.
2 - Algae are usually aquatic, either marine (seaweed) or Fresh water. Few occur in moist soil. Wet rocks, moist tree trunks also. Fungi live in aquatic, sub-aquatic and terrestrial habitats.
3 -Body called ‘Thallus’ is unicellular flagellated (in Chlamydomonas), non-flagellat-ed (in Chlorella),colonial form (in Volvox) or filamentous (Ulothrix,Spirogyra).In some forms, it is flat and leaf like (Laminaria)and attaches to rock by structure called ‘Holdfast’. Fungi has branched Hyphae, which gets interwoven to form Mycelium.
4 -Algae are of different colours because of presence of different pigments in it. Green Algae has green pigments-Chlorophyll-a and Chlorophyll b in girdle /spiral shaped chloroplast. Brown pigment-Fucoxanthin, Red pigment-Phycoerythrin and blue pigment-Phycocyanin impart brown, red and blue colours to algae. Red Algae secretes and deposits calcium carbonate and appears like coral.E.g. of red algae are Polysiphonia,Gelidium, Batrachospermum.
5 - Algae show autotrophic nutrition. Fungi show heterotrophic nutrition.
6 -Algae reproduce vegetatively by fragmentation, budding or tubers. Asexual reproduction occurs by motile and non motile spores. Sexual reproduction occurs by Isogamy, Anisogamy and Oogamy.
7 -Life Cycle has distinct haploid and diploid phases, which alternate thus exhibiting Alternation of Generations. On the basis of pigment colours, algae is further sub divided into Chlorophyceae (Green), Phaeophyceae (brown) and Rhodophyceae (red) Algae.
(5.3) BRYOPHYTA (Gk. Bryon-Moss phyton-Plant)
1 . These occur in damp places, mostly during rainy season growing as green mat on rocks, soil, wall, tree trunks etc.
2 . Thalloid body is flat (Riccia) / liver shaped (Marchantia). So, these are also called as ‘Liverworts’.
3 . Some plants have body differentiated into stem and leaf like structure. Thallus is attached to soil, rocks, wall by root like structures called as ‘ Rhizoids’.
4 . Lack vascular tissues.
5 . Vegetative reproduction is very common and occurs by fragmentation, Gemmae and Tubers. Sexual reproduction involves male sex organs (Antheredium) and female sex organs (Archegonium).
6 . Life cycle has haploid and diploid phases. Haploid (Gametophytic) phase and diploid (Sporophytic) phase alternate with each other exhibiting Alternation of Generations’.
7 . Based on plant body and method of sexual reproduction, Bryophytes are sub-divided into Hepaticae (e.g.Marchantia) ,Anthocerotae (e.g. Anthoceros) and Musci (Funaria) Classes.
(5.4) PTERIDOPHYTA: (Pterido- Pteris phyton-plant)
1 - Occur in humid and tropical climate on soil, rocks or on other plants. Equisetum grows near water bodies.
2 - Body has underground stem liske Rhizome having roots and aerial shoots with leaves. Some have simple leaves with single vein and some have compound leaves with several leaflets (pinnules).Compound leaves in Adiantum are arranged beautifully and look like maiden’s hair. So it is also called as ‘Maiden Hair Fern’.
3 - Sporangia occur on leaves in clusters called ‘Sori’. Spore bearing leaves are called ‘Sporophylls’.
4 - Vegetative reproduction occurs by fragmentation and budding. In ‘Walking fern’-Adiantum, new plant is produced wherever its leaf tip comes in contact with the soil.
5 - Plant body represents Sporophyte and is diploid. Spores are haploid and germinate on moist soil to form thallus like structure called ‘Prothallus’ which represents Gametophyte.
6 - Male sex organs (Antheridium) and female sex organs (Archegonium) help in sexual reproduction.
7 - Alternation of Generations is there. Dominant phase is Sporophytic.
8 - Pteridophyta is divided into 4 sub-classes-Psilopsida, Lycopsida, Sphienopsida and Pteropsida on basis of body organization, leaf structure and location of sporangia.
9 - Examples are-Dryopteris, Pteris, Lycopodium, Selaginella, Adiantum.
(5.5) GYMNOSPERMS: - (Gk. Gymnos-naked sperma-seed)
1. Found in cool climate of hills. Some occur in warm climate also (Cycas).
2. These are generally tall woody trees. Few are bushes (Ephedra) or climbers (Gnetum).
3. Have well developed vascular system of xylem and phloem,which helps in absorbing and conducting water in tall trees.
4 . Have no flowers but have seeds.
5. Leaf like structures called Sporophylls bear sporangia. Megasporophyll has Megasporangium (ovule). Microsporophyll has Microsporangium (pollen sac).Microsporophylls and Megasporophylls form male cones and female cones respectively. Later, these produce male and female gametes respectively.
6. After fertilization, zygote (2N) is formed in ovule, which ripens to form seed.
7. Alternation of Generation is there. Sporophyte is dominant phase.
8. These are further sub divided into 3 classes- Cycadopsida, Coniferopsida and Gnetopsida on the basis of nature of leaves, wood, vascular system & reproductive structure
9. Examples are Cycas, Araucaria, Ephedra, Gnetum, Pinus, Abies.
(5.6) ANGIOSPERMS: - (Gk. Angion- vessel sperma-seed)- Flowering Plants.
(i) Occur in diverse habitats and almost everywhere. These are trees, shrubs and herbs.
(ii) Body is clearly differentiated into roots, stem and leaves.
(iii) They have highly developed vascular system of xylem (with vessels) and phloem (With companion cells).
(iv) Sporophylls are aggregated to form flowers. Stamens in flower represent microspor–ophyll whereas carpel represents megasporophyll.
(v) Pollination occurs through several agencies like birds, animals, insects etc.
(vi) After fertilization, ovule remains inside ovary, which later develops into fruit.
(vii) These show Double Fertilization.
(viii) Examples are sunflower, Maize, Wheat etc.
CLASSIFICATION OF ANGIOSPERMS: -
Most well known system of classification of Angiosperms was given by George Bentham (1800-1864) and Joseph Dalton Hooker (1817-1911). They published it in their book ‘Genra Plantarum’ (1862-1883)
Bentham and Hooker’s System :-It is based on form and relationship of plants. It is handy and accurate and covered about 97,000 species of seed plants. The Phanerogams were divided into classes, which were further sub divided into sub-classes. Sub-classes have ‘series’ which are further categorized into ‘Cohorts’ (equivalent to orders in other systems). Cohorts, further have ‘orders’ (equivalent to Families). There are total 202 orders (families). Few orders could not be placed properly in schematic arrangement and so ,because of their unusual position, these are called ‘Ordines Anomali’.
(Has 6 cohorts, 37 orders) (Has 3 cohorts, 9 orders) (7 orders)
Cohort I Ranales (8 orders) Cohort I Rubiales (2 orders) order130 Nyctaginaceae
Order1 Ranunculaceae order 85 Caprifoliaceae order131 Illecebraceae
Order 2 Dilleniaceae order 86 Rubiaceae order132 Amarantaceae
Order 3 Calycanthaceae Cohort II Asterales (4 orders) order133 Chenopodiaceae
Order 4 Magnoliaceae order 87 Valerianea order134 Phytolaccaceae
Order 5 Annonaceae order 88 Dipsacaceae order135 Batideae
Order 6 Menispermaceae order 89 Calyceraeae order136 Polygonaceae
Order 7 Berberideae order 90 Compositae Series 2 Multiovulatae-
Order 8 Nymphaeaceae Cohort III Campanulales (3 orders) Aquaticeae
Cohort II Parietales (9orders) Order 91 Stylidieae (1 order)
Order 9 Sarraceniaceae order 92 Goodeniaceae order137 Podostemaceae
Order 10 Papaveraceae order 93 Campanulaceae Series 3 Multiovulatae-
Order11 Cruciferae Series 2 Heteromerae terrestres
Order 12 Capparidaceae (has 3 cohorts, 12 orders) (3 orders)
Order 13 Resedaceae Cohort IV Ericales (6 orders) order138 Nepenthaceae
Order 14 Cistineae order 94 Vaccinaceae order 139 Cytinaceae
Order 15 Violaceae order 95 Ericaceae order140 Aristolochiaceae
Order 16 Canellaceae order 96 Monotropeae Series 4 Microembryeae
Order 17 Bixineae order 97 Epacrideae (4 orders)
Cohort III Polygalineae (4 orders) order 141 Piperaceae
Order18 Pittosporeae order 98 Diapensiaceae order142 Chloranthaceae
Order 19 Tremandreae order 99 Lennoaceae order143 Myristicaceae
Order 20 Polygaleae Cohort V Primulales (3 orders)order144 Monimiaceae
Order 21 Vochysiaceae order 100 Plumbagineae
Cohort IV Caryophyllineae (4 orders) Series V Daphnales
Order 22 Frankeniaceae order 101 Primulaceae (5 orders)
Order 23 Caryophyllaceae order 102 Myrsineae order145 Laurineae
Order 24 Portulaceae Cohort VI Ebenales (3 orders)order146 Proteaceae
Order 25 Tamaricaceae order 103 Sapotaceae order 147 Thymelaeaceae
Cohort V Guttiferales (6 orders) order 104 Ebenaceae order148 Penaeaceae
Order 26 Elatineae order 105 Styracaceae order149 Elaeagnaceae
Order 27 Hypericineae Series 3 Bicarpellatae Series VI Achlamydosporae
Order 28 Guttiferae (has 4 cohorts, 27 orders) (3 orders)
Order 29 Trenstroemiaceae Cohort VII Gentianales (6 orders)order150 Loranthaceae
Order 30 Dipterocarpaceae order 106 Oleaceae order151 Santalaceae
Order 31 Chlaenaceae order 107 Salvadoraceae order 152 Balanophoreae
Cohort VI Malvales (3 orders) order 108 Apocynaceae Series VII Unisexuales
Order 32 Malvaceae order 109 Asclepiadaceae (9 orders)
Order 33 Sterculiaceae order 110 Loganiaceae order 153 Euphorbiaceae
Order 34 Tiliaceae order 111 Gentianaceae order154 Balanopseae
Series 2 Disciflorae (has 4 cohorts order155 Urticaceae
21 orders & 2 anomalous orders) Cohort VIII Polemoniales order156 Plantanaceae
Cohort VII Geraniales (has 11orders) (5 orders) order157 Leitneriaceae
Order 35 Lineae order 112 Polemoniaceae order158 Juglandeae
Order36 Humiriaceae order 113 Hydrophyllaceae order159 Myricaceae
Order 37 Malpighiaceae order 114 Boraginaceae order160 Casuarinaceae
Order 38 Zygophylleae order 115 Convolvulaceae order161 Cupuliferae
Order 39 Geraniaceae order 116 Solanaceae Series 8 Ordines Anomali
Order 40 Rutaceae Cohort IX Personales (8 orders) (4 orders)
Order 41 Simaroubeae order 117 Scrophulariaceae order162 Salicaceae
Order 42 Ochnaceae order118 Orobanchaceae order163 Lacistemaceae
Order 43 Burseraceae order119 Lentibulariaceae order164 Empetraceae
Order 44 Meliaceae order120 Columelliaceae order165 Ceratophyllaceae
Order 45 Chailletiaceae order121 Gesneriaceae
Cohort VIII Olacales(has 3orders) order122 Bignoniaceae
Order 46 Olacineae order123 Pedaliaceae
Order 47 Ilicineae order124 Acanthaceae
Order 48 Cyrillae Cohort X Lamiales (5 orders)
Cohort IX Celastrales (has 4 orders) order125 Myoporineae
Order 49 Celastrineae order 126 Selagineae
Order 50 Stackhousieae order 127 Verbenaceae
Order 51 Rhamnaceae order 128 Labiatae
Order 52 Ampelideae (Vitaceae) order 129 Anomalous-Plantagineae
Cohort X Sapindales (has 3 orders)
Order 53 Sapindaceae
Order 54 Sabiaceae
Order 55 Anacardiaceae
(5.1) CLASSIFICATION OF PLANTS:
According to various systems, the classifications of plants are as given below-
(a) Artificial System: - In this system, plants were classified on the basis of one or few convenient superficial characters. Pliny the Elder (79, AD) first of all give artificial system of classification.
- Theophrastus proposed first a kind of artificial system of classification on the basis of habit of plants. He classified them as herbs, shrubs, under shrubs, trees etc.
- C. Linnaeus (1707-1778) used artificial system of classification based only upon floral parts. The plants were classified as Hypogyny, Perigyny and Epigyny. It is also known as Sexual / Numerical System of classification. Linnaeus also classified plants on the basis of number and position of stamens. Plants with one stamen belonged to class Monandria and with 20 or more stamens to class Icosandria.He divided plants into 24 classes. Out of these, 23 classes were of Flowering Plants and 24rth class was of Flowerless plant(Cryptogamia). He published papers like Flora Laponica, Species Plantarum, Critica Botanicaa and Systema Naturae.
This system was inadequate. So, classification according to it was not accepted.
(b) This system is more common and divides plant kingdom into two sub-kingdoms Cryptogamae and Phanerogamae.
Sub-kingdoms were named on the basis of presence or absence of seeds / flowers.
Cryptogamae –(kryptos-concealed gamos-marriage) These included all non-flowering plants without seeds like Algae, Fungi, Lichens, Mosses and Ferns.
Phanerogamae- (Phaneros- visible gamos-marriage) or Spermatophytes (sperma-seed-phyton-plant)-These included all flowering plants with seeds.
Phanerogams can be distinguished from Cryptogams by presence of well-developed vascular tissue for conduction of water, minerals (xylem) and food (phloem). Plants with their vascular tissues resembling trachea (wind pipe) of animals are called Tracheophytes.
(5.2) THALLOPHYTA- ALGAE
1 - It includes both, Algae and fungi.
2 - Algae are usually aquatic, either marine (seaweed) or Fresh water. Few occur in moist soil. Wet rocks, moist tree trunks also. Fungi live in aquatic, sub-aquatic and terrestrial habitats.
3 -Body called ‘Thallus’ is unicellular flagellated (in Chlamydomonas), non-flagellat-ed (in Chlorella),colonial form (in Volvox) or filamentous (Ulothrix,Spirogyra).In some forms, it is flat and leaf like (Laminaria)and attaches to rock by structure called ‘Holdfast’. Fungi has branched Hyphae, which gets interwoven to form Mycelium.
4 -Algae are of different colours because of presence of different pigments in it. Green Algae has green pigments-Chlorophyll-a and Chlorophyll b in girdle /spiral shaped chloroplast. Brown pigment-Fucoxanthin, Red pigment-Phycoerythrin and blue pigment-Phycocyanin impart brown, red and blue colours to algae. Red Algae secretes and deposits calcium carbonate and appears like coral.E.g. of red algae are Polysiphonia,Gelidium, Batrachospermum.
5 - Algae show autotrophic nutrition. Fungi show heterotrophic nutrition.
6 -Algae reproduce vegetatively by fragmentation, budding or tubers. Asexual reproduction occurs by motile and non motile spores. Sexual reproduction occurs by Isogamy, Anisogamy and Oogamy.
7 -Life Cycle has distinct haploid and diploid phases, which alternate thus exhibiting Alternation of Generations. On the basis of pigment colours, algae is further sub divided into Chlorophyceae (Green), Phaeophyceae (brown) and Rhodophyceae (red) Algae.
(5.3) BRYOPHYTA (Gk. Bryon-Moss phyton-Plant)
1 . These occur in damp places, mostly during rainy season growing as green mat on rocks, soil, wall, tree trunks etc.
2 . Thalloid body is flat (Riccia) / liver shaped (Marchantia). So, these are also called as ‘Liverworts’.
3 . Some plants have body differentiated into stem and leaf like structure. Thallus is attached to soil, rocks, wall by root like structures called as ‘ Rhizoids’.
4 . Lack vascular tissues.
5 . Vegetative reproduction is very common and occurs by fragmentation, Gemmae and Tubers. Sexual reproduction involves male sex organs (Antheredium) and female sex organs (Archegonium).
6 . Life cycle has haploid and diploid phases. Haploid (Gametophytic) phase and diploid (Sporophytic) phase alternate with each other exhibiting Alternation of Generations’.
7 . Based on plant body and method of sexual reproduction, Bryophytes are sub-divided into Hepaticae (e.g.Marchantia) ,Anthocerotae (e.g. Anthoceros) and Musci (Funaria) Classes.
(5.4) PTERIDOPHYTA: (Pterido- Pteris phyton-plant)
1 - Occur in humid and tropical climate on soil, rocks or on other plants. Equisetum grows near water bodies.
2 - Body has underground stem liske Rhizome having roots and aerial shoots with leaves. Some have simple leaves with single vein and some have compound leaves with several leaflets (pinnules).Compound leaves in Adiantum are arranged beautifully and look like maiden’s hair. So it is also called as ‘Maiden Hair Fern’.
3 - Sporangia occur on leaves in clusters called ‘Sori’. Spore bearing leaves are called ‘Sporophylls’.
4 - Vegetative reproduction occurs by fragmentation and budding. In ‘Walking fern’-Adiantum, new plant is produced wherever its leaf tip comes in contact with the soil.
5 - Plant body represents Sporophyte and is diploid. Spores are haploid and germinate on moist soil to form thallus like structure called ‘Prothallus’ which represents Gametophyte.
6 - Male sex organs (Antheridium) and female sex organs (Archegonium) help in sexual reproduction.
7 - Alternation of Generations is there. Dominant phase is Sporophytic.
8 - Pteridophyta is divided into 4 sub-classes-Psilopsida, Lycopsida, Sphienopsida and Pteropsida on basis of body organization, leaf structure and location of sporangia.
9 - Examples are-Dryopteris, Pteris, Lycopodium, Selaginella, Adiantum.
(5.5) GYMNOSPERMS: - (Gk. Gymnos-naked sperma-seed)
1. Found in cool climate of hills. Some occur in warm climate also (Cycas).
2. These are generally tall woody trees. Few are bushes (Ephedra) or climbers (Gnetum).
3. Have well developed vascular system of xylem and phloem,which helps in absorbing and conducting water in tall trees.
4 . Have no flowers but have seeds.
5. Leaf like structures called Sporophylls bear sporangia. Megasporophyll has Megasporangium (ovule). Microsporophyll has Microsporangium (pollen sac).Microsporophylls and Megasporophylls form male cones and female cones respectively. Later, these produce male and female gametes respectively.
6. After fertilization, zygote (2N) is formed in ovule, which ripens to form seed.
7. Alternation of Generation is there. Sporophyte is dominant phase.
8. These are further sub divided into 3 classes- Cycadopsida, Coniferopsida and Gnetopsida on the basis of nature of leaves, wood, vascular system & reproductive structure
9. Examples are Cycas, Araucaria, Ephedra, Gnetum, Pinus, Abies.
(5.6) ANGIOSPERMS: - (Gk. Angion- vessel sperma-seed)- Flowering Plants.
(i) Occur in diverse habitats and almost everywhere. These are trees, shrubs and herbs.
(ii) Body is clearly differentiated into roots, stem and leaves.
(iii) They have highly developed vascular system of xylem (with vessels) and phloem (With companion cells).
(iv) Sporophylls are aggregated to form flowers. Stamens in flower represent microspor–ophyll whereas carpel represents megasporophyll.
(v) Pollination occurs through several agencies like birds, animals, insects etc.
(vi) After fertilization, ovule remains inside ovary, which later develops into fruit.
(vii) These show Double Fertilization.
(viii) Examples are sunflower, Maize, Wheat etc.
CLASSIFICATION OF ANGIOSPERMS: -
Most well known system of classification of Angiosperms was given by George Bentham (1800-1864) and Joseph Dalton Hooker (1817-1911). They published it in their book ‘Genra Plantarum’ (1862-1883)
Bentham and Hooker’s System :-It is based on form and relationship of plants. It is handy and accurate and covered about 97,000 species of seed plants. The Phanerogams were divided into classes, which were further sub divided into sub-classes. Sub-classes have ‘series’ which are further categorized into ‘Cohorts’ (equivalent to orders in other systems). Cohorts, further have ‘orders’ (equivalent to Families). There are total 202 orders (families). Few orders could not be placed properly in schematic arrangement and so ,because of their unusual position, these are called ‘Ordines Anomali’.
(Has 6 cohorts, 37 orders) (Has 3 cohorts, 9 orders) (7 orders)
Cohort I Ranales (8 orders) Cohort I Rubiales (2 orders) order130 Nyctaginaceae
Order1 Ranunculaceae order 85 Caprifoliaceae order131 Illecebraceae
Order 2 Dilleniaceae order 86 Rubiaceae order132 Amarantaceae
Order 3 Calycanthaceae Cohort II Asterales (4 orders) order133 Chenopodiaceae
Order 4 Magnoliaceae order 87 Valerianea order134 Phytolaccaceae
Order 5 Annonaceae order 88 Dipsacaceae order135 Batideae
Order 6 Menispermaceae order 89 Calyceraeae order136 Polygonaceae
Order 7 Berberideae order 90 Compositae Series 2 Multiovulatae-
Order 8 Nymphaeaceae Cohort III Campanulales (3 orders) Aquaticeae
Cohort II Parietales (9orders) Order 91 Stylidieae (1 order)
Order 9 Sarraceniaceae order 92 Goodeniaceae order137 Podostemaceae
Order 10 Papaveraceae order 93 Campanulaceae Series 3 Multiovulatae-
Order11 Cruciferae Series 2 Heteromerae terrestres
Order 12 Capparidaceae (has 3 cohorts, 12 orders) (3 orders)
Order 13 Resedaceae Cohort IV Ericales (6 orders) order138 Nepenthaceae
Order 14 Cistineae order 94 Vaccinaceae order 139 Cytinaceae
Order 15 Violaceae order 95 Ericaceae order140 Aristolochiaceae
Order 16 Canellaceae order 96 Monotropeae Series 4 Microembryeae
Order 17 Bixineae order 97 Epacrideae (4 orders)
Cohort III Polygalineae (4 orders) order 141 Piperaceae
Order18 Pittosporeae order 98 Diapensiaceae order142 Chloranthaceae
Order 19 Tremandreae order 99 Lennoaceae order143 Myristicaceae
Order 20 Polygaleae Cohort V Primulales (3 orders)order144 Monimiaceae
Order 21 Vochysiaceae order 100 Plumbagineae
Cohort IV Caryophyllineae (4 orders) Series V Daphnales
Order 22 Frankeniaceae order 101 Primulaceae (5 orders)
Order 23 Caryophyllaceae order 102 Myrsineae order145 Laurineae
Order 24 Portulaceae Cohort VI Ebenales (3 orders)order146 Proteaceae
Order 25 Tamaricaceae order 103 Sapotaceae order 147 Thymelaeaceae
Cohort V Guttiferales (6 orders) order 104 Ebenaceae order148 Penaeaceae
Order 26 Elatineae order 105 Styracaceae order149 Elaeagnaceae
Order 27 Hypericineae Series 3 Bicarpellatae Series VI Achlamydosporae
Order 28 Guttiferae (has 4 cohorts, 27 orders) (3 orders)
Order 29 Trenstroemiaceae Cohort VII Gentianales (6 orders)order150 Loranthaceae
Order 30 Dipterocarpaceae order 106 Oleaceae order151 Santalaceae
Order 31 Chlaenaceae order 107 Salvadoraceae order 152 Balanophoreae
Cohort VI Malvales (3 orders) order 108 Apocynaceae Series VII Unisexuales
Order 32 Malvaceae order 109 Asclepiadaceae (9 orders)
Order 33 Sterculiaceae order 110 Loganiaceae order 153 Euphorbiaceae
Order 34 Tiliaceae order 111 Gentianaceae order154 Balanopseae
Series 2 Disciflorae (has 4 cohorts order155 Urticaceae
21 orders & 2 anomalous orders) Cohort VIII Polemoniales order156 Plantanaceae
Cohort VII Geraniales (has 11orders) (5 orders) order157 Leitneriaceae
Order 35 Lineae order 112 Polemoniaceae order158 Juglandeae
Order36 Humiriaceae order 113 Hydrophyllaceae order159 Myricaceae
Order 37 Malpighiaceae order 114 Boraginaceae order160 Casuarinaceae
Order 38 Zygophylleae order 115 Convolvulaceae order161 Cupuliferae
Order 39 Geraniaceae order 116 Solanaceae Series 8 Ordines Anomali
Order 40 Rutaceae Cohort IX Personales (8 orders) (4 orders)
Order 41 Simaroubeae order 117 Scrophulariaceae order162 Salicaceae
Order 42 Ochnaceae order118 Orobanchaceae order163 Lacistemaceae
Order 43 Burseraceae order119 Lentibulariaceae order164 Empetraceae
Order 44 Meliaceae order120 Columelliaceae order165 Ceratophyllaceae
Order 45 Chailletiaceae order121 Gesneriaceae
Cohort VIII Olacales(has 3orders) order122 Bignoniaceae
Order 46 Olacineae order123 Pedaliaceae
Order 47 Ilicineae order124 Acanthaceae
Order 48 Cyrillae Cohort X Lamiales (5 orders)
Cohort IX Celastrales (has 4 orders) order125 Myoporineae
Order 49 Celastrineae order 126 Selagineae
Order 50 Stackhousieae order 127 Verbenaceae
Order 51 Rhamnaceae order 128 Labiatae
Order 52 Ampelideae (Vitaceae) order 129 Anomalous-Plantagineae
Cohort X Sapindales (has 3 orders)
Order 53 Sapindaceae
Order 54 Sabiaceae
Order 55 Anacardiaceae
2 Anomalous orders
Order 56 Coriarieae
Order 57 Moringeae
Series 3 Calyciflorae 7 Series of class Monycotyledonae
(Has 5 cohorts & 27 orders) Series 1 Microspermae (3 orders)
Cohort XI Rosales (has 9 orders) order169 Hydrocharitaceae
Order 58 Connaraceae order 170 Burmanniaceae
Order 59 Leguminosae order 171 Orchidaceae
Order 60 Rosaceae Series 2 Epigynae (7 orders)
Order 61 Saxifrageae order 172 Scitaminae
Order 62 Crassulaceae order 173 Bromiliaceae
Order 63 Droseraceae order174 Hoemadoraceae
Order 64 Hamamelideae order175 Iridaceae
Order 65 Bruniaceae order176 Amaryllidaceae
Order 66 Haloragaceae order177 Taccaceae
Cohort XII Myrtales (has 6 orders) order178 Dioscoreaceae
Order 67 Rhizophoreae Series 3 Coronariae (8 orders)
Order 68 Combretaceae order179 Roxburghiaceae
Order 69 Myrtaceae order180 Liliaceae
Order 70 Melastomataceae order181 Pontederiaceae
Order 71 Lythraceae order 182 Philydraceae
Order 72 Onagraceae order 183 Xyrideae
Cohort XIII Passiflorales (has 7 orders) order184 Mayaceae
Order 73 Samydaceae order185 Commelinaceae
Order 74 Loasaceae order186 Rapataceae
Order 75 Turneraceae Series 4 Calycineae (3 orders)
Order 76 Passifloreae order187 Flagellarieae
Order 77 Cucurbitaceae order188 Juncaceae
Order 78 Begoniaceae order189 Palmae
Order 79 Datiscaceae Series 5 Nudiflorae (5 orders)
Cohort XIV Ficoidales (has 2 orders) order190 Pandanaceae
Order 80 Cacteae order191 Cyclanthaceae
Order 81 Ficoideae order192 Typhaceae
Cohort XV Umbellales (has 3 orders) order193 Aroideae
Order 82 Umbelliferae order194 Lemnaceae
Order 83 Araliaceae Series 6 Apocarpae (3 orders)
Order 84 Ceraniaceae order195 Triurideae
Order196 Alismaceae
Order197 Najadaceae
Series 7 Glumaceae (5 orders)
Order198 Eriocauleae
Order199 Centrolepideae
Order200 Restiaceae
Order201 Cyperaceae
Order202 Gramineae
CLASS I: Dicotyledons
- Seeds are with 2 cotyledons.
-Leaves have reticulate venation with alternate, spiral or whorled arrangement.
-Flowers are tetramerous or pentamerous (i.e. have four or five members in floral whorls).
-Vascular bundle is open type i.e. cambium present between xylem and phloem.
Class was further sub-divided into sub-classes on basis of no. and nature of floral whorls. On basis of position of ovary, sub-classes were further sub divided into series, which were further categorized into ‘cohorts’ (equivalent to order) and ‘orders’ (equivalent to Families).
(a) Sub-class: Polypetalae (poly-free petalae-petals)
-Corolla has whorl of 4-5 petals, which are free from one another. Calyx present.
-Sepals and petals are distinct and form two whorls.
Series (i) Thalamiflorae
-Many stamens, sepals and petals arising from thalamus above ovary.
-Ovary superior without any disc.
-Sepals are free from ovary.
-It has 6 cohorts and 34 orders. (See chart)
Series (ii) Disciflorae
-Flowers hypogynous, definite stamens.
-Ovary superior with nectariferous disc at the base.
-Sepals are either free (polysepalous) or fused (gamosepalous).
-It has 4 cohorts and 23 orders. (See chart).
Series (iii) Calyciflorae
-Flowers are perigynous or epigynous
-Inferior ovary.
-Sepals are fused and calyx forms a tube around ovary.
-Includes 5 cohorts and 27 orders. (See chart).
(b) Sub-class: Gamopetalae ( gamo-fused petalae-petals)
-Corolla has 4-5 petals, which are either partially or completely fused with one another.
-Sepals and petals are distinct.
-Stamens are attached to petals (Epipetalous).
Series (i) Inferae
-Stamens equal to the number of corolla lobes.
-Epigynous flowers.
-Inferior ovary.
-Has 3 cohorts and 9 orders. (See chart).
Series (ii) Heteromerae
-Stamens either equal to or twice the number of lobes of corolla.
-Stamens free from corolla.
-Hypogynous flower with more than two carpels.
-Superior ovary.
-Has 3 cohorts and 12 orders. (See chart).
Series (iii) Bicarpellatae
-Stamens less in number than corolla lobes.
-Two or more carpels with superior ovary.
-Hypogynous flower.
-Includes 4 cohorts and 24 orders.
(c ) Sub-class : Monochlamydae (Incompletae / Apetalae)
( mono-one chlamydae-whorl)
-Incomplete flowers.
-Sepals and Petals are not distinct.
-Flowers have only one whorl with no petals. (Sepaloid).
-No cohorts.
Series (i) Curvembryae
-Embryo curved around the endosperm.
-One ovule.
-It has 7orders. (See chart).
Series (ii) Multiovulatae Aquaticeae
-Many ovules.
-Are submerged aquatic plants.
-It has 1 order.(see chart)
Series (iii) Multiovulatae Terrestres
-Many ovules.
-Terrestrial plants.
-Has 3 orders. (See chart).
Series (iv) Microembryae
-Minute embryo.
-Has 4 orders.(see chart)
Series (v) Daphnales
-Ovary with one carpel.
-Ovary with one ovule.
-It has 5 orders. (See chart)
Series (vi) Achlamydosporeae
-Inferior, unilocular ovary with 1-3 ovules.
-It has 3 orders. (See chart)
Series (vii) Unisexuales
-Unisexual flowers.
-Has 9 orders. (See chart)
Series (viii) Ordines Anomali
-Families of uncertain relationships.
-It has 4 orders. (See chart).
CLASS II- Gymnospermeae (Plants with naked seeds or seed plants without flowers).
This class is in between dicotyledons and monocotyledons. Some characters of it are: -
(i) These are usually resinous trees or shrubs found predominantly in snowy, cold regions. E.g. Cycas.Some are very large and live for thousands of years.e.g.Sequoia sempervirens.
(ii) Leaves are needle like.
(iii) These have well developed vascular system of xylem (without vessels) and Phloem(without companion cells).
(iv) Flowers absent. Have two types of sporophylls-Microsporophylls & Megasporo-phylls. The two sporophylls form ‘Cones’- Male cones (Pollen cones) and Female Cones. (Seed cones).
(v) Seeds are naked i.e. don’t occur inside fruit and lie exposed on surface of mega-sporophyll i.e. ovules are naked and don’t occur inside ovary.
(vi) Pollination is direct and generally through wind.
(vii) Male and Female gametophyte present.
(viii) Male gametophyte forms two gametes, which show Double Fertilization.
(ix) It has been divided into 3 families- Cycadaceae, Conifereae & Gnetaceae.
(x) E.g. Cycas, Pinus, Ephedra, Araucaria, Cedrus.
(xi) It includes 3 orders. (See chart).
CLASS III: Monocotyledons -These are usually herbs with simple large leaves showing parallel venation.
-Trimerous flowers i.e. floral parts exist in sets of three or its multiples.
-Embryo has one cotyledon.
-Primary roots are short-lived. Tap roots absent, Adventitious roots present.
-Vascular bundles scattered and closed type.
-E.g. Smilax, Colocasia, Banana, Palm, Grasses, Orchids, Bamboo, Lilies etc.
-These have been divided into 7 series on basis of nature of perianth and condition of Ovary
Series (i) Microspermae
-Petaloid perianth.
-Ovary inferior, unilocular with epigynous flower.
-Seeds minute, numerous and without endosperm.
-It has 3 orders. (See chart).
Series (ii) Epigynae
-Partly Petaloid perianth.
-Ovary inferior.
-Seeds are endospermic with nutritive tissue.
-It has 4 orders. (See chart).
Series (iii) Coronariae
-Petaloid perianth.
-Ovary superior and free.
-Seeds endospermic.
-It has 8 orders. (See chart).
Series (iv) Calycineae
-Perianth sepaloid.
-Ovary superior and free.
-Seeds endospermic.
-Includes 3 orders. (See chart).
Series (v) Nudiflorae
-Perianth absent or reduced to hair or scales.
-Ovary superior with solitary carpels.
-Endospermic seeds.
-Has 5 orders. (See chart).
Series (vi) Apocarpae
-Perianth with one or two whorls. Sometimes, it may be absent.
-Ovary superior. Carpels free.
-Endosperm absent.
-Has 3 orders. (See chart).
Series (vii) Glumaceae
-Perianth is either absent or is scaly or highly reduced.
-Unilocular ovary with single ovule.
-Has 5 orders. (See chart).
Merits of Bentham and Hooker’s System: -(i) Every genus and species was studied from actual specimens and preserved herbarium sheets. Their description was based on detailed studies and dissections.
(ii) The descriptions given were easy to follow and were of practical utility for identification of species upto Family level. Information related to their geographical distribution was also given.
(iii) In the division Polypetalae, new series Disciflorae is put in between Calyciflorae and Thalamiflorae.
(iv) Unlike de Candolle, who distributed conifers among well defined taxas of dicots, Gymnosperms were considered a third taxon by Bentham and Hooker and placed in Between monocots and dicots.
(v) Genra was further sub-divided into sub-genra, which included important relevant sps. This made study more convenient.
(vi) Some aspects of system show affinity with modern concept of evolution. E.g. order Ranales is placed in the beginning and recent taxonomic studies have also established Ranales among the most primitive orders.
(vii) The placing of monocots after dicots is also according to evolutionary trends.
Demerits of Bentham and Hooker’s System:
(i) Placing of gymnosperms between dicots and monocots is anomalous.
(ii) Among dicots, Monochlamydae is considered highly evolved and Polypetalae as most primitive. Gamopetalae is placed in between the two. This is contrary to evolutionary trends.
(iii) Monochlamydae is not well-defined group as several families which have affinity with Polypetalae are included in it.
(iv) The placement of families like Asteraceae in beginning of Gamopetalae and Orchidaceae in Microspermae do not justify recent evolutionary trends.(v) Some closely related families are kept apart.
Order 57 Moringeae
Series 3 Calyciflorae 7 Series of class Monycotyledonae
(Has 5 cohorts & 27 orders) Series 1 Microspermae (3 orders)
Cohort XI Rosales (has 9 orders) order169 Hydrocharitaceae
Order 58 Connaraceae order 170 Burmanniaceae
Order 59 Leguminosae order 171 Orchidaceae
Order 60 Rosaceae Series 2 Epigynae (7 orders)
Order 61 Saxifrageae order 172 Scitaminae
Order 62 Crassulaceae order 173 Bromiliaceae
Order 63 Droseraceae order174 Hoemadoraceae
Order 64 Hamamelideae order175 Iridaceae
Order 65 Bruniaceae order176 Amaryllidaceae
Order 66 Haloragaceae order177 Taccaceae
Cohort XII Myrtales (has 6 orders) order178 Dioscoreaceae
Order 67 Rhizophoreae Series 3 Coronariae (8 orders)
Order 68 Combretaceae order179 Roxburghiaceae
Order 69 Myrtaceae order180 Liliaceae
Order 70 Melastomataceae order181 Pontederiaceae
Order 71 Lythraceae order 182 Philydraceae
Order 72 Onagraceae order 183 Xyrideae
Cohort XIII Passiflorales (has 7 orders) order184 Mayaceae
Order 73 Samydaceae order185 Commelinaceae
Order 74 Loasaceae order186 Rapataceae
Order 75 Turneraceae Series 4 Calycineae (3 orders)
Order 76 Passifloreae order187 Flagellarieae
Order 77 Cucurbitaceae order188 Juncaceae
Order 78 Begoniaceae order189 Palmae
Order 79 Datiscaceae Series 5 Nudiflorae (5 orders)
Cohort XIV Ficoidales (has 2 orders) order190 Pandanaceae
Order 80 Cacteae order191 Cyclanthaceae
Order 81 Ficoideae order192 Typhaceae
Cohort XV Umbellales (has 3 orders) order193 Aroideae
Order 82 Umbelliferae order194 Lemnaceae
Order 83 Araliaceae Series 6 Apocarpae (3 orders)
Order 84 Ceraniaceae order195 Triurideae
Order196 Alismaceae
Order197 Najadaceae
Series 7 Glumaceae (5 orders)
Order198 Eriocauleae
Order199 Centrolepideae
Order200 Restiaceae
Order201 Cyperaceae
Order202 Gramineae
CLASS I: Dicotyledons
- Seeds are with 2 cotyledons.
-Leaves have reticulate venation with alternate, spiral or whorled arrangement.
-Flowers are tetramerous or pentamerous (i.e. have four or five members in floral whorls).
-Vascular bundle is open type i.e. cambium present between xylem and phloem.
Class was further sub-divided into sub-classes on basis of no. and nature of floral whorls. On basis of position of ovary, sub-classes were further sub divided into series, which were further categorized into ‘cohorts’ (equivalent to order) and ‘orders’ (equivalent to Families).
(a) Sub-class: Polypetalae (poly-free petalae-petals)
-Corolla has whorl of 4-5 petals, which are free from one another. Calyx present.
-Sepals and petals are distinct and form two whorls.
Series (i) Thalamiflorae
-Many stamens, sepals and petals arising from thalamus above ovary.
-Ovary superior without any disc.
-Sepals are free from ovary.
-It has 6 cohorts and 34 orders. (See chart)
Series (ii) Disciflorae
-Flowers hypogynous, definite stamens.
-Ovary superior with nectariferous disc at the base.
-Sepals are either free (polysepalous) or fused (gamosepalous).
-It has 4 cohorts and 23 orders. (See chart).
Series (iii) Calyciflorae
-Flowers are perigynous or epigynous
-Inferior ovary.
-Sepals are fused and calyx forms a tube around ovary.
-Includes 5 cohorts and 27 orders. (See chart).
(b) Sub-class: Gamopetalae ( gamo-fused petalae-petals)
-Corolla has 4-5 petals, which are either partially or completely fused with one another.
-Sepals and petals are distinct.
-Stamens are attached to petals (Epipetalous).
Series (i) Inferae
-Stamens equal to the number of corolla lobes.
-Epigynous flowers.
-Inferior ovary.
-Has 3 cohorts and 9 orders. (See chart).
Series (ii) Heteromerae
-Stamens either equal to or twice the number of lobes of corolla.
-Stamens free from corolla.
-Hypogynous flower with more than two carpels.
-Superior ovary.
-Has 3 cohorts and 12 orders. (See chart).
Series (iii) Bicarpellatae
-Stamens less in number than corolla lobes.
-Two or more carpels with superior ovary.
-Hypogynous flower.
-Includes 4 cohorts and 24 orders.
(c ) Sub-class : Monochlamydae (Incompletae / Apetalae)
( mono-one chlamydae-whorl)
-Incomplete flowers.
-Sepals and Petals are not distinct.
-Flowers have only one whorl with no petals. (Sepaloid).
-No cohorts.
Series (i) Curvembryae
-Embryo curved around the endosperm.
-One ovule.
-It has 7orders. (See chart).
Series (ii) Multiovulatae Aquaticeae
-Many ovules.
-Are submerged aquatic plants.
-It has 1 order.(see chart)
Series (iii) Multiovulatae Terrestres
-Many ovules.
-Terrestrial plants.
-Has 3 orders. (See chart).
Series (iv) Microembryae
-Minute embryo.
-Has 4 orders.(see chart)
Series (v) Daphnales
-Ovary with one carpel.
-Ovary with one ovule.
-It has 5 orders. (See chart)
Series (vi) Achlamydosporeae
-Inferior, unilocular ovary with 1-3 ovules.
-It has 3 orders. (See chart)
Series (vii) Unisexuales
-Unisexual flowers.
-Has 9 orders. (See chart)
Series (viii) Ordines Anomali
-Families of uncertain relationships.
-It has 4 orders. (See chart).
CLASS II- Gymnospermeae (Plants with naked seeds or seed plants without flowers).
This class is in between dicotyledons and monocotyledons. Some characters of it are: -
(i) These are usually resinous trees or shrubs found predominantly in snowy, cold regions. E.g. Cycas.Some are very large and live for thousands of years.e.g.Sequoia sempervirens.
(ii) Leaves are needle like.
(iii) These have well developed vascular system of xylem (without vessels) and Phloem(without companion cells).
(iv) Flowers absent. Have two types of sporophylls-Microsporophylls & Megasporo-phylls. The two sporophylls form ‘Cones’- Male cones (Pollen cones) and Female Cones. (Seed cones).
(v) Seeds are naked i.e. don’t occur inside fruit and lie exposed on surface of mega-sporophyll i.e. ovules are naked and don’t occur inside ovary.
(vi) Pollination is direct and generally through wind.
(vii) Male and Female gametophyte present.
(viii) Male gametophyte forms two gametes, which show Double Fertilization.
(ix) It has been divided into 3 families- Cycadaceae, Conifereae & Gnetaceae.
(x) E.g. Cycas, Pinus, Ephedra, Araucaria, Cedrus.
(xi) It includes 3 orders. (See chart).
CLASS III: Monocotyledons -These are usually herbs with simple large leaves showing parallel venation.
-Trimerous flowers i.e. floral parts exist in sets of three or its multiples.
-Embryo has one cotyledon.
-Primary roots are short-lived. Tap roots absent, Adventitious roots present.
-Vascular bundles scattered and closed type.
-E.g. Smilax, Colocasia, Banana, Palm, Grasses, Orchids, Bamboo, Lilies etc.
-These have been divided into 7 series on basis of nature of perianth and condition of Ovary
Series (i) Microspermae
-Petaloid perianth.
-Ovary inferior, unilocular with epigynous flower.
-Seeds minute, numerous and without endosperm.
-It has 3 orders. (See chart).
Series (ii) Epigynae
-Partly Petaloid perianth.
-Ovary inferior.
-Seeds are endospermic with nutritive tissue.
-It has 4 orders. (See chart).
Series (iii) Coronariae
-Petaloid perianth.
-Ovary superior and free.
-Seeds endospermic.
-It has 8 orders. (See chart).
Series (iv) Calycineae
-Perianth sepaloid.
-Ovary superior and free.
-Seeds endospermic.
-Includes 3 orders. (See chart).
Series (v) Nudiflorae
-Perianth absent or reduced to hair or scales.
-Ovary superior with solitary carpels.
-Endospermic seeds.
-Has 5 orders. (See chart).
Series (vi) Apocarpae
-Perianth with one or two whorls. Sometimes, it may be absent.
-Ovary superior. Carpels free.
-Endosperm absent.
-Has 3 orders. (See chart).
Series (vii) Glumaceae
-Perianth is either absent or is scaly or highly reduced.
-Unilocular ovary with single ovule.
-Has 5 orders. (See chart).
Merits of Bentham and Hooker’s System: -(i) Every genus and species was studied from actual specimens and preserved herbarium sheets. Their description was based on detailed studies and dissections.
(ii) The descriptions given were easy to follow and were of practical utility for identification of species upto Family level. Information related to their geographical distribution was also given.
(iii) In the division Polypetalae, new series Disciflorae is put in between Calyciflorae and Thalamiflorae.
(iv) Unlike de Candolle, who distributed conifers among well defined taxas of dicots, Gymnosperms were considered a third taxon by Bentham and Hooker and placed in Between monocots and dicots.
(v) Genra was further sub-divided into sub-genra, which included important relevant sps. This made study more convenient.
(vi) Some aspects of system show affinity with modern concept of evolution. E.g. order Ranales is placed in the beginning and recent taxonomic studies have also established Ranales among the most primitive orders.
(vii) The placing of monocots after dicots is also according to evolutionary trends.
Demerits of Bentham and Hooker’s System:
(i) Placing of gymnosperms between dicots and monocots is anomalous.
(ii) Among dicots, Monochlamydae is considered highly evolved and Polypetalae as most primitive. Gamopetalae is placed in between the two. This is contrary to evolutionary trends.
(iii) Monochlamydae is not well-defined group as several families which have affinity with Polypetalae are included in it.
(iv) The placement of families like Asteraceae in beginning of Gamopetalae and Orchidaceae in Microspermae do not justify recent evolutionary trends.(v) Some closely related families are kept apart.
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