UPSC MainsBOTANY-PAPER-I202310 Marks150 Words
Q15.

Alphonse de Candolle classified plants of economic importance into various classes. List these classes and state two examples from each.

How to Approach

This question requires a recall-based answer focusing on Alphonse de Candolle’s classification of economically important plants. The approach should be direct – listing the classes and providing two examples for each. A structured presentation, potentially using a table, will enhance clarity and readability. Focus on accuracy and avoid unnecessary elaboration. The answer should demonstrate knowledge of historical botanical classification systems.

Model Answer

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Introduction

Alphonse de Candolle, a Swiss botanist, significantly contributed to plant taxonomy and phytogeography. In his ‘Prodromus Systematis Naturalis Regni Vegetabilis’ (1824-1873), he proposed a natural system of plant classification. Crucially, he also categorized plants based on their economic importance, recognizing the profound impact of plants on human civilization. This classification, though superseded by modern systems, remains historically significant for understanding the early recognition of economic botany. He divided plants into classes based on their uses, providing a framework for understanding plant-human interactions.

De Candolle’s Classes of Economically Important Plants

De Candolle classified plants of economic importance into the following classes, with examples:

  • Cereals (Gramineae): Plants cultivated for their edible grains.
    • Triticum aestivum (Common Wheat)
    • Oryza sativa (Rice)
  • Legumes (Leguminosae): Plants belonging to the pea family, valued for their protein-rich seeds.
    • Glycine max (Soybean)
    • Phaseolus vulgaris (Common Bean)
  • Oilseeds (Oleaginous Plants): Plants yielding oils used for food, fuel, and industrial purposes.
    • Brassica napus (Rapeseed/Canola)
    • Helianthus annuus (Sunflower)
  • Fibrous Plants: Plants providing fibers used for textiles, ropes, and paper.
    • Gossypium spp. (Cotton)
    • Linum usitatissimum (Flax)
  • Sugar-yielding Plants: Plants accumulating sugars used for sweetening and industrial processes.
    • Saccharum officinarum (Sugarcane)
    • Beta vulgaris (Sugar Beet)
  • Medicinal Plants: Plants possessing therapeutic properties used in traditional and modern medicine.
    • Catharanthus roseus (Madagascar Periwinkle – source of vincristine and vinblastine)
    • Adhatoda vasica (Vasaka – used for cough and bronchitis)
  • Plants yielding Resins & Gums: Plants producing substances used in varnishes, adhesives, and other industrial applications.
    • Pinus roxburghii (Chir Pine – source of resin)
    • Acacia senegal (Gum Arabic tree)
  • Plants yielding Beverages: Plants used for producing stimulating or refreshing drinks.
    • Camellia sinensis (Tea)
    • Coffea arabica (Coffee)

De Candolle’s classification, while not adhering to modern phylogenetic principles, was a pioneering attempt to categorize plants based on their utility to humankind. It laid the groundwork for the development of economic botany as a distinct field of study.

Conclusion

Alphonse de Candolle’s classification of economically important plants, though a historical artifact, provides valuable insight into the early understanding of plant-human relationships. His categorization, based on practical uses like cereals, legumes, and medicinal properties, highlights the long-standing dependence of human societies on the plant kingdom. While modern taxonomy relies on evolutionary relationships, de Candolle’s work remains a significant milestone in the history of botany and economic botany.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Phytogeography
The study of the geographic distribution of plants, encompassing factors influencing their spread and abundance.

Key Statistics

Approximately 80,000 plant species are estimated to be used for medicinal purposes globally.

Source: WHO Traditional Medicine Strategy 2002-2005

The global economic value of plant-derived medicines is estimated to be over $100 billion annually (as of 2020).

Source: World Health Organization (WHO) estimates (knowledge cutoff 2023)

Examples

Jatropha curcas

Jatropha curcas, a plant yielding oil, has gained prominence as a potential biofuel source, demonstrating the continued relevance of economic botany in addressing contemporary energy challenges.

Frequently Asked Questions

Is De Candolle’s classification still used today?

No, De Candolle’s classification is largely superseded by modern phylogenetic systems based on genetic and evolutionary relationships. However, it remains historically important for understanding the development of economic botany.

Topics Covered

BotanyEconomic BotanyTaxonomyDe CandolleEconomic PlantsClassificationBotany