Bentham & Hooker System of Classification
An interactive botanical study guide to understand the classical classification system proposed by George Bentham and Joseph Dalton Hooker.
1. Overview of Bentham & Hooker Classification
Bentham and Hooker's system is one of the most important classical systems of plant classification. It was published in their monumental work Genera Plantarum between 1862 and 1883.
George Bentham
George Bentham was an important British botanist who worked extensively on plant taxonomy and collaborated with J. D. Hooker in developing the system.
Joseph Dalton Hooker
J. D. Hooker was a major British botanist and director of the Royal Botanic Gardens, Kew. His botanical expertise contributed greatly to the development of the system.
Genera Plantarum
The classification was presented in Genera Plantarum, published during 1862–1883.
2. Interactive Classification Flowchart
Click any classification group to jump directly to its detailed explanation.
3. Class – Dicotyledones
Dicotyledones were characterized by having two cotyledons and were divided into three important subclasses.
Polypetalae
In Polypetalae, petals are generally free from one another.
Flowers generally hypogynous; stamens usually arise from the thalamus.
A prominent disc is associated with the floral structures in many groups.
Flowers generally show perigynous or epigynous relationships of floral parts.
Gamopetalae
In Gamopetalae, the petals are generally united to form a gamopetalous or sympetalous corolla.
Ovary generally inferior.
Traditionally characterized by variation in the number of carpels.
Many groups are characterized by a bicarpellary ovary.
Monochlamydeae
A traditional grouping in which the perianth is single or absent. This is a historical grouping and is not regarded as a natural phylogenetic clade by modern taxonomy.
4. Polypetalae – Series
Series I – Thalamiflorae
The flowers are generally hypogynous. Stamens are commonly attached to the thalamus.
Series II – Disciflorae
The presence of a floral disc is an important traditional character of this series.
Series III – Calyciflorae
The floral structure is traditionally associated with perigynous or epigynous conditions.
5. Class – Gymnospermae
Gymnosperms were recognized as a separate class because their ovules are not enclosed within an ovary as in angiosperms.
Gymnospermae
In Bentham and Hooker's system, Gymnospermae occurs as one of the three principal classes of Phanerogamia.
Important Character
The ovules are exposed or “naked” rather than enclosed inside an angiospermous ovary.
6. Class – Monocotyledones
Monocotyledones were characterized by possessing a single cotyledon and were divided into seven series.
Microspermae
A traditional series of monocotyledonous plants based on seed and floral characters.
Epigynae
Groups traditionally associated with an inferior ovary and epigynous floral structures.
Coronariae
A traditional grouping containing several petaloid monocotyledonous groups.
Calycinae
A traditional series based mainly on floral and perianth characters.
Nudiflorae
Historically included monocot groups having reduced or inconspicuous floral envelopes.
Apocarpae
Traditionally associated with groups showing separate carpels.
Glumaceae
A major traditional series containing grass-like and sedge-like groups.
7. Complete Classification Sequence
Phanerogamia
The major classes are:
Dicotyledones
Polypetalae
Gamopetalae
Monocotyledones
8. Three Principal Classes – Comparison
| Character | Dicotyledones | Gymnospermae | Monocotyledones |
|---|---|---|---|
| Cotyledons | Two | Usually two or more | One |
| Ovules | Enclosed | Naked / exposed | Enclosed |
| Major position | First principal class | Second principal class | Third principal class |
| Dicot subclasses | Polypetalae, Gamopetalae, Monochlamydeae | — | — |
| Monocot series | — | — | Seven series |
9. Important Features for Examination
Natural System
Bentham and Hooker's classification is regarded as a classical natural system.
Genera Plantarum
The system was published in Genera Plantarum during 1862–1883.
Three Classes
Remember: Dicotyledones, Gymnospermae, Monocotyledones.
Three Dicot Subclasses
Polypetalae → Gamopetalae → Monochlamydeae
Polypetalae
Three series: Thalamiflorae, Disciflorae, Calyciflorae.
Gamopetalae
Three series: Inferae, Heteromerae, Bicarpellatae.
Monocotyledones
Seven series: Microspermae, Epigynae, Coronariae, Calycinae, Nudiflorae, Apocarpae, Glumaceae.
10. Merits and Limitations
Merits
- Based on a large amount of comparative botanical information.
- Genera were arranged in a practical and systematic manner.
- Extremely useful for identification and herbarium work.
- The system became an important foundation for later taxonomic work.
Limitations
- It predates modern evolutionary and molecular evidence.
- Some groups placed together are not evolutionarily related.
- Monochlamydeae is considered an artificial grouping under modern phylogenetic understanding.
- Gymnosperms and angiosperms are now interpreted using evolutionary relationships rather than only traditional morphology.
11. One-Minute Revision
- Bentham + Hooker → Natural system.
- Main work → Genera Plantarum.
- Phanerogamia → three principal classes.
- Dicotyledones → three subclasses.
- Polypetalae → three series.
- Gamopetalae → three series.
- Monochlamydeae → seven traditional series in the detailed historical arrangement.
- Monocotyledones → seven series.
- Modern taxonomy → primarily evolutionary / phylogenetic.
12. Interactive Quick Quiz
Q1. Which is a principal class in Bentham & Hooker's Phanerogam classification?
Q2. How many principal classes are recognized in Phanerogamia?
Q3. Which subclass has generally free petals?
