Question
Question: ‘Ordinales Anomali' of Bentham and Hooker includes a. Seed plants showing abnormal forms of growth...
‘Ordinales Anomali' of Bentham and Hooker includes
a. Seed plants showing abnormal forms of growth and development.
b. Plants represented only in a fossil state.
c. Plants described in the literature, but which Bentham and Hooker did not see in the original.
d. A few orders which could not be placed satisfactorily in the classification.
Solution
Hint: The Bentham and Hooker classification was based on certain affinities among the plant species but few species showed anomalies.
Complete step-by-step solution:
George Bentham and Joseph Dalton Hooker were two botanists working in the Royal Botanical Garden, Kew, England. They devised a taxonomic classification for the seed-bearing plants. There were many orders which were disputed. ‘Ordinales Anomali' includes those orders which could not be placed satisfactorily in the classification.
Additional Information:
1. The George and Bentham classification of phanerogams (seed-bearing plants) was published in the book Genera Plantarum and exemplary imprimis between 1862 to 1883.
2. The classification did not take into account evolution.
3. They divided plants into Gymnosperms, Monocotyledons, and Dicotyledons.
4. The classification was based on the hypothesis that evolution occurs with reduction. Hence, monocots were placed after dicots.
5. The larger genera were further divided into small subgenera.
6. The dicotyledons on the basis of presence or absence of petals were further divided into three subclasses polypetalae, gamopetalae, and monochlamydeae.
7. The monochlamydeae bear features dissimilar to the other groups.
8. The major disadvantage of the system lies in its phylogeny. It did not satisfy the evolutionary relationship between organisms.
So, the correct answer is ‘A few orders which could not be placed satisfactorily in the classification’.
Note: The major demerits of the classification are as follows
1. It was based on single and artificial characters due to which the closely related families were placed far apart.
2. Gymnosperm was placed between the dicots and monocots but phylogenetically gymnosperms evolved prior to the development of monocots and dicots.
The Theory of Organic Evolution by Darwin proved it wrong.