Bentham and Hooker's classification system from 1862 divided plants into three main classes - dicotyledons, gymnosperms, and monocotyledons - based on morphological features. Dicotyledons were further divided into three subclasses of polypetalae, gamopetalae, and monochlamydeae. This system focused on natural relationships between plants rather than artificial systems, and described over 97,000 species. Though it had some limitations like anomalous placements, it was a major natural system and paved the way for modern phylogenetic approaches.
Angiosperms are the flowering plants also known as Magnoliophyta. The botanical term "Angiosperm" meaning ‘bottle or vessel’ is derived from the ancient Greek. These are the most diverse group of land plants. Angiosperms are seed-producing plants and the distinguished features of angiosperms over gymnosperms are angiosperms bear flowers, endosperm within the seeds and the production of fruits that contain the seed. According to the botanists the flowering plants diversified and widespread 120 million years ago. The classification of the flowering plants also has a long history.
In the past, classification systems were typically produced by an individual botanist or by a small group resulting large number of systems. Different systems and their updates were generally favored in different countries. Bentham and Hooker’s system was popular in the Britain and the Engler’s system was famous in the Europe etc. These systems were introduced before the availability of genetic evidences and angiosperms were classified using their morphology and biochemistry. After the 1980’s genetic evidences were available and phylogenetic methods came into the classification procedures.
In the late 1990s, an informal group of researchers from major institutions worldwide came together and they established the Angiosperm Phylogeny Group (APG). The objective was to provide a widely accepted and more stable point of reference for angiosperm classification. APG I was published in 1998 as their first attempt in Annals of the Missouri Botanical Garden. The initial 1998 paper by the APG made angiosperms the first large group of organisms to be systematically re-classified primarily on the basis of genetic characteristics. The group emphasized the need for a classification system for angiosperms at the level of families, orders and above. The existed systems are rejected is because they are not phylogenetically classified. The outline of a phylogenetic tree of all flowering plants became established and several well supported major clades involving many families of flowering plants were identified. The new knowledge of phylogeny revealed relationships in conflict with the then widely used modern classifications.
The principles of APG system are retaining the Linnean system of orders and families, Use of monophyletic groups (Consist of all descendants of a common ancestor), taking a broad approach to defining the limits of groups such as orders and families and use of term ‘clades’ above or parallel to the level of orders and families. A major outcome of the classification is the disappearance of the traditional division of the flowering plants into two groups, which are monocots and dicots.
Even though there are several controversies about APG the botanists worldwide are influenced by the concept and are currently practice the system.
The "Telome theory" of Walter Zimmermann (1930, 1952) is the most accepted theory that is based on fossil record and synthesizes the major steps in the evolution of vascular plants.
It describes how the primitive type of vascular plants developed from Rhynia like plants.
Angiosperm Phylogeny Group classification
APG I
APG II
APG III
APG IV
Molecular Based system
features and organization
Merits and demerits
Difference in APG system.
Angiosperms are the flowering plants also known as Magnoliophyta. The botanical term "Angiosperm" meaning ‘bottle or vessel’ is derived from the ancient Greek. These are the most diverse group of land plants. Angiosperms are seed-producing plants and the distinguished features of angiosperms over gymnosperms are angiosperms bear flowers, endosperm within the seeds and the production of fruits that contain the seed. According to the botanists the flowering plants diversified and widespread 120 million years ago. The classification of the flowering plants also has a long history.
In the past, classification systems were typically produced by an individual botanist or by a small group resulting large number of systems. Different systems and their updates were generally favored in different countries. Bentham and Hooker’s system was popular in the Britain and the Engler’s system was famous in the Europe etc. These systems were introduced before the availability of genetic evidences and angiosperms were classified using their morphology and biochemistry. After the 1980’s genetic evidences were available and phylogenetic methods came into the classification procedures.
In the late 1990s, an informal group of researchers from major institutions worldwide came together and they established the Angiosperm Phylogeny Group (APG). The objective was to provide a widely accepted and more stable point of reference for angiosperm classification. APG I was published in 1998 as their first attempt in Annals of the Missouri Botanical Garden. The initial 1998 paper by the APG made angiosperms the first large group of organisms to be systematically re-classified primarily on the basis of genetic characteristics. The group emphasized the need for a classification system for angiosperms at the level of families, orders and above. The existed systems are rejected is because they are not phylogenetically classified. The outline of a phylogenetic tree of all flowering plants became established and several well supported major clades involving many families of flowering plants were identified. The new knowledge of phylogeny revealed relationships in conflict with the then widely used modern classifications.
The principles of APG system are retaining the Linnean system of orders and families, Use of monophyletic groups (Consist of all descendants of a common ancestor), taking a broad approach to defining the limits of groups such as orders and families and use of term ‘clades’ above or parallel to the level of orders and families. A major outcome of the classification is the disappearance of the traditional division of the flowering plants into two groups, which are monocots and dicots.
Even though there are several controversies about APG the botanists worldwide are influenced by the concept and are currently practice the system.
The "Telome theory" of Walter Zimmermann (1930, 1952) is the most accepted theory that is based on fossil record and synthesizes the major steps in the evolution of vascular plants.
It describes how the primitive type of vascular plants developed from Rhynia like plants.
Angiosperm Phylogeny Group classification
APG I
APG II
APG III
APG IV
Molecular Based system
features and organization
Merits and demerits
Difference in APG system.
Classification denotes the arrangement of a single plant or group of plants an distinct category following a system of nomenclature, and in accordance with a particular and well established plan.
From its initiation in 1998, the Angiosperm Phylogeny Group (APG) has focused on the production of an ever-more stable system of classification of the flowering plants (angiosperms). Based largely on analyses of DNA sequence data, the system is compiled by a larger group of experts than any previous system and has the advantage of being testable, allowing for confidence levels in the system to be estimated for the first time.
This presentation was given by Dr. Avishek Bhattacharjee in Botanical Nomenclature Course held in Botanical Survey of India, Eastern Regional Centre, Shillong in November 2016. This may be helpful to the undergraduate and post graduate Botany students to understand different types of taxonomic literature, especially Flora, Revision and Monograph.
This is a detailed presentation on Morphology, anatomy and reproduction of Marchantia spp. with high quality pics and eye capturing transitions and animations
This presentation has been intended to offer a bird's eye view about the phylogenetic classification of the plant kingdom in general and the Engler and Prantl system in particular with merits and demerits.
Classification denotes the arrangement of a single plant or group of plants an distinct category following a system of nomenclature, and in accordance with a particular and well established plan.
From its initiation in 1998, the Angiosperm Phylogeny Group (APG) has focused on the production of an ever-more stable system of classification of the flowering plants (angiosperms). Based largely on analyses of DNA sequence data, the system is compiled by a larger group of experts than any previous system and has the advantage of being testable, allowing for confidence levels in the system to be estimated for the first time.
This presentation was given by Dr. Avishek Bhattacharjee in Botanical Nomenclature Course held in Botanical Survey of India, Eastern Regional Centre, Shillong in November 2016. This may be helpful to the undergraduate and post graduate Botany students to understand different types of taxonomic literature, especially Flora, Revision and Monograph.
This is a detailed presentation on Morphology, anatomy and reproduction of Marchantia spp. with high quality pics and eye capturing transitions and animations
This presentation has been intended to offer a bird's eye view about the phylogenetic classification of the plant kingdom in general and the Engler and Prantl system in particular with merits and demerits.
This PPT has been made to explore the plant classification in general and the classification as made by Bentham & Hooker for the classification of the flowering plants. It also offers the history of plant classification along with the merits and demerits of this aforesaid classification.
BENTHAM AND HOOKER SYSTEM OF CLASSIFICATION.pptxRASHMI M G
Bentham and Hooker system of plant classification is the best example of natural system of classification
Their contribution to the field of taxonomy and plant systematics is enormous
Their classification is of practical importance even today
The 3 volume work ‘Genera Plantarum’ published by them It consists of descriptions with names and classification of about 97,205 seed plants (flowering plants) belonging to 7569 genera of 200 families of flowering plants.
Arrangement of plants in an orderly sequence based upon their similarities and relationship in hierarchy such as species, genus, family, order, class and division in conformity with the nomenclatural system
The closely related plants are kept within a group and unrelated plants are kept far apart in separate groups.
Palynology: History, branches, basic principles and application, collection o...Sangram Sahoo
Palynology: History, branches, basic principles and application, collection of polleniferous materials from modern samples (i.e. living flowers, spider webs, tree barks and honey samples) and sediments
Similar to Classification of Plants : Bentham & Hooker (20)
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Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
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2. CLASSIFICATION OF PLANTS
Artificial Systems Phylogenetic systems
(Based on morphological features)
(Based on evolutionary and
genetic relationship)
Natural systems
(Based on their natural affinities)
3. ARTIFICIAL SYSTEMS
These systems of classification were based on one or few morphological
characters.
a. Theophrastus (370 – 285 BC)
b. Otto Brunfels (1464-1534)
c. Andrea Caesalpino (1519-1603)
d. Joseph Pitton de Tournefort (1656-1708)
e. John Ray (1627-1705)
f. Carolus Linnaeus (1707-1778)
4. NATURAL SYSTEMS
In these systems the organisms are classified on the basis of their natural
affinities (i.e. the basic similarities in the morphology) rather than on a
single character for determining the affinities.
a. A.L. de Jussieu (1748-1836)
b. A.P. de Candolie (1778-1841)
c. Bentham and Hooker’s Classification
5. PHYLOGENETIC SYSTEMS:
Classification based on evolutionary features is known as phylogenetic
system.
a. Engler and Prantl (1884-1930)
b. John Hutchinson (1884-1972)
7. BENTHAM AND HOOKER’S CLASSIFICATION
CLASS-I DICOTYLEDONAE
• Leaves show reticulate venation
• Flowers are tetramerous or pentamerous.
Polypetalae Monochlamydeae
Gamopetalae
8. BENTHAM AND HOOKER’S CLASSIFICATION
SUB-CLASS-I POLYPETALAE
Flowers with free petals come under polypetalae.
The flowers are with distinct calyx and corolla.
THALAMIFLORAE DISCIFLORAE CALCYFLORAE
Flowers with conical or
dome shaped
thalamus
Flowers having prominent
disc shaped thalamus below
ovary
Flowers with cup shaped
thalamus.
Ovary is superior Ovary is superior Ovary is superior or inferior,
sometimes half inferior
6 orders and 34
families
4 orders and 23 families 5 orders and 27 families
9. BENTHAM AND HOOKER’S CLASSIFICATION
SUB-CLASS-II GAMOPETALAE
Flowers with petals , which are either partially or completely fused to one
another .
The flowers are with distinct sepals and petals.
INFERAE HETEROMERAE BICARPELLATE
Flowers are epigynous Flowers having prominent
disc shaped thalamus below
ovary
Flowers with cup shaped
thalamus.
Ovary is inferior Ovary is superior with more
than two carpels
Ovary is inferior, with two
carpels only.
3 orders and 9 families 3 orders and 12 families 4 orders and 24 families
10. BENTHAM AND HOOKER’S CLASSIFICATION
SUB-CLASS-III MONOCHLAMYDEAE
Flowers with single whorl of perianth(sepals and petals not distinguished).
Flowers are incomplete.
Tepals are present in two whorls.
Sometimes, both the whorls are absent.
Includes 8 series and 36 families
11. BENTHAM AND HOOKER’S CLASSIFICATION
CLASS-II GYMNOSPERMAE
• Naked ovules or seeds.
• Ovary is absent.
Gnetaceae Cycadaceae
Conifera
12. BENTHAM AND HOOKER’S CLASSIFICATION
CLASS-III MONOCOTYLEDONAE
• Leaves show parallel venation.
• Flowers are trimerous
• Have fibrous root system
• Has 7 series and 34 families.
13. BENTHAM AND HOOKER’S CLASSIFICATION
o SALIENT FEATURES:
1. It is a classification of only the “seed plants” or phanerogams.
2. They described 97,205 species of seed plants belonging to 7,569 genera of202
families starting from Ranunculaceae up to Gramineae.
3. They classified all the seed plants into 3 groups or classes i.e. Dicotyledons (165
families), gymnosperms (3 families) and monocotyledons (34 families).
4. Monocotyledons were described after the dicotyledones.
14. BENTHAM AND HOOKER’S CLASSIFICATION
o SALIENT FEATURES:
5. The dicotyledons were divided into 3 Divisions (Polypetalae, Gamopetalae and
Monochlamydeae) and 14 series. Each series again divided into cohorts (modern
orders) and cohorts into orders (modern families).
6. The authors did not mention anything about the origin of the angiosperms.
7. Creation of the Disciflorae, a taxon not described by the earlier taxonomists.
8. Among the Monochlamydeae, major taxa, like the series, were divided on the
basis of terrestrial and aquatic habits.
15. BENTHAM AND HOOKER’S CLASSIFICATION
o MERITS :
1. Bentham and Hooker’s classification is the most natural system, based on
actual examination of specimens.
2. The description of plants is quite accurate and reliable.
3. The flora describes geographical distribution of species and genera.
4. The generic descriptions are complete, accurate and based on direct
observations.
16. BENTHAM AND HOOKER’S CLASSIFICATION
o MERITS :
5. Larger genera have been divided into sub genera, each with specific number of
species.
6. Although this system is natural, most of the aspects of this system show affinity
to modern concepts of evolution.For example-dicots begin with the order Ranales
which are now universally considered as to be the most primitive angiosperms.
7. Placing of monocots after the dicot is again a natural one and according to
evolutionary trends.
8. As it is is easy to follow, it is used as a key for the identification of plants in
Kew herbarium and several other herbaria in the world.
9. The placing of gamopetalae after polypetalae is justified since union of petalsis
considered to be an advanced feature over the free condition.
17. BENTHAM AND HOOKER’S CLASSIFICATION
o DEMERITS :
1. Keeping gymnosperms in between dicots and monocots is anomalous.
2. Subclass monochlamydeae is quite artificial.
3. Placing of monochlamydeae after gamopetalae does not seem to be natural.
4. Some of the closely related species are placed distantly while distant species are
placed close to each other.
18. BENTHAM AND HOOKER’S CLASSIFICATION
o DEMERITS :
5. Certain families of monochlamydeae are closely related to families in
polypetalae, e.g. Chenopodiaceae and Caryophyllaceae.
6. Advanced families, such as Orchiadaceae have been considered primitive in
this system by placing them in the beginning. Placing of Orchidaceae in the
beginning of monocotyledons is unnatural as it is one of the most advanced
families of monocots. Similarly, Compositae (Asteraceae) has been placed near
the beginning of gamopetalae which is quite unnatural.
7. Liliaceae and Amaryllidaceae were kept apart merely on the basis of
characters of ovary though they are very closely related.
8. There were no phylogenetic considerations
![CLASSIFICATION OF PLANTS
[BENTHAM AND HOOKER]
BY : S. DASH](https://image.slidesharecdn.com/benthamhooker-210522170053/85/Classification-of-Plants-Bentham-Hooker-1-320.jpg)
