Engler and Prantl System of Classification

Adolf Engler (1844-1938), a German botanist and Professor in Botany at University of Berlin for thirty years proposed a phylogenetic system of classification based on evolutionary relationship which was first published as a guide to the Botanical Garden of Breslau in a book entitled ‘Syllabus der Pflanzenfamilien’ in 1892. He was also Director of Botanical Gardens from1889 to1921. Later on, Engler in collaboration with other German botanist Karl E. Prantl elaborated his study on classification of plants and monumental work was published in details in a book entitled ‘Die Nuturlichen Pflanzenfamilien’ in 23 volumes (1887-1915). Engler and Prantl system of classification of seed plants is based on complexity of flower, fruit and development of seed. Salient features of Engler and Prantl’s system of classification is mentioned below:  The wind pollinated flowers are primitive whereas insect-pollinated flowers are advanced.  Unisexuals plants are primitive and bisexual plants are advanced. They further assumed that bisexual flowers was been evolved from unisexual flowers.  Flowers with free flowers parts such as free sepals, free petals, free stamen and free carpel is more primitive over united flower parts.  Among united flowers, if only sepal united, condition is primitive, sepals and petals united more advanced and if all flower parts are in united condition is said to be most advanced.  They further assumed that angiosperms evolved from gymnosperms.  Monocots evolved first from angiosperms and dicots from monocots. Hence, they consider monocots as primitive and dicots as advanced.  They combined Monochlamydae and Polypetalae in a separate group called Archichlamydae (with free sepals and petals).  Archichlamydae gives rise to Metachlamydae.  Megasporophyll give rise to female flowers and microsporophyll give rise to male flowers. Engler and Prantl divided plant kingdom into 13 divisions. Out of which, 12 divisions describes the bacteria, algae, fungi, bryophyta and pteridophyta and 13th divison describe seed bearing plants i.e. Embryophyta. The outline of Embryophyta proposed by Engler and Prantl has been mentioned below:  Embryophyta was divided into two sub-divisions on the basis of seed viz. Gymnospermae and Angiospermae. o Gymnospermae – all plants with naked seeds or ovules. o Angiospermae – All plants with covered or enclosed seeds or ovules.  Gymnospermae was further divided into seven orders which has been mentioned below: I. Cycadofilicales II. Cycadales III. Bennetitales IV. Ginkgoales V. Coniferales VI. Cordaitales VII. Gnetales  They divided Angiospermae into two classes viz. I. I. Monocotyledonae II. Dicotyledonae I. Monocotyledonae They classified plants of monocotyledonae into 11 orders (Pandanales, ) and 45 families. This group of plants starts with order Pandanales and ends with Microspermae. Family starts with Typhaceae of Pandanales and ends with Orchidaceae of order Microspermae. II. Dicotyledonae They classified dicotyledonae into 2 subclasses viz. I. Archichlamydae – plants with free petals was grouped under this subclass and was further divided into 33 orders. This group of plants starts with order Verticillatae and ends with order Umbelliflorae. Starting family of this subclass Archichlamydae begins with Casuarinaceae and ends with Cornaceae of Umbelliflorae. II. Metachlamydeae (Sympetalae) – plants with fused petals was grouped under this subclass and was further classified into 11 orders. This subclass starts with order Ericales with family Clethraceae and ends with order Campanulales with family Asteraceae or Compositae. Merits  System proposed considers all group of plant kingdom starting from bacteria to Angiosperms.  Sympetalae is equivalent to Gamopetalae of Bentham and Hooker system of classification.  Gymnosperm has been considered separately and is justified.  Plants with inferior ovary have been placed at the end of the subclasses.  Plants have been arranged in order of advancement from hypogyny to epigyny.  Like others, they also placed Orchidaceae at the end of Microspermae considering them most advanced.  Placement of Asteraceae or Compositae at the end of Dicots is justified.  Demerits  Monocots are considered primitive over dicots.  Grouping of Apetalous and Polypetalous families together is not justified.  System proposed does not deserve much more practical applications.