Carolus Linnaeus Classification system

The classification system of Linnaeus was based on floral characteristics. He chiefly used characters of stamen’s. Therefore, his system is called sexual system. This system is very convenient for the identification of plants. I le presented his classification system in two books. These books are Species Plantarum and Genera Plantarum.

Advantages of Linnaeus system: Linnaeus was first to introduced some system of classification. It gave some basic knowledge of classification. So it was widely accepted by the taxonomists of that time. It provided a reference work. He gave clear cut concept of species. This concept is still used today.

Disadvantage of Linnaeus system: Linnaeus declared his system as artificial or temporary. He realized that that this system should be changed with some natural system. Linnaeus grouped some unrelated plants due to similarity in flower structure. Similarly. Linnaeus was a religious person.opposed the concept of evolution in classification.

Scheme of Linnaeus system: Linnaeus divided be plants into twenty four classes. He mostly used the characteristics of stamens to differentiate between classes. He also used tne conditions of perigynous, hypogynous, dynamous, filaments fused or not fused, number of fasicles anther attachment, presene of male and female flowers. These classes are:

I. Class Monandria: They have single stamen. Examples: Canna

2. Class Diandria: They have two stamens. Example: Salva
3. Class T Hand ria: They have three stamens. Example: Poa
4. Class Tetrandria: They have four stamens. Example: Cuscuta
   2. Class Pentandira: They have five stamens. Example: Daucus
   3. Class Hexandria: They have six stamens. Example: Rumex

   4. Class Heptandria: They have seven stamens. Example: Aesculus

   5. Class Octandrit They have eight stamens. Example: Sapindus

   6. Class Enneandria: They have nine stamens. Example: Rheum

   7. Class Decandria: They have ten stamens. Example: Silene

   8. Class Dodecandria: They have 12-19 stamens. Example: Euphorbia

   9. Class Icosandria: They have 20 or more stamens and hypogynous condition. Example: Cactus.

   10. Class Polyandria: They have 20 or more stamens with hypogynous condition. Example: Ranunculus

   11. Class Didynamia: They have didynamous stamens. Example: • Bignonia

   12. Class Tetradynamia: They have tetradynamous stamens. Example: Trifolium.

   13. Class Monodelphia: They have fused filament with one fasicle. Example: Sida

   17. Class Diadelphia: They have fUsed filament with two fasieles. Example: Polygala

   18. Class Polydelphia: Their stamens are fused with several fasicles. Example: Citrus

   19. Class Syngenesia: They have anther connate. Example: Viola

   20. Class Gynandria: Their stamens are fused to their pistils. Example: Orchis

   21. ..Class Monoecia: They have male and female flowers on same plant. Example: Belida

   22. Class Dioecia: They lune male and female flowers on different plant. Example: Najas

   23. Class Polygamia: Their Ilmsers are polygamous. Example: Pupil

   24. Class Cryptogamia: Flowers are absent or not apparent. Example: Fucus

   Classification system of Jussieu

   This system was proposed by Bernard de Jussieu and Laurent Jussiett. They introduced Natural classification system. They divided the plants into 100 orders and 15 classes. They recognized the difference between Monocotyledons and Dicotyledons. They separated the cryptograms (non-seed producing) from seed producing plants. They divided the plants into three groups:

       I. Acotyledons: They are non-seed producing plants.

   2. Monocotyledons: They hat c single cotyledons.
   3. Dicotyledons: They have two cotyledons.

   Augustine Pyrame de Condone improved the Jussietis system. I le divided the plants into 213 orders. lie used morphological characteristics to differentiate between these orders.