BENTHAM AND HOOKER SYSTEM OF CLASSIFICATION

BENTHAM AND HOOKER SYSTEM OF CLASSIFICATION

The well known English systematists who brought out jointly ‗Genera Plantarum‘ (1862 - 1883) and their classification is used throughout the British empire. In our country the Central National Herbarium at Sibpur (Howrah) W. Bengal is maintained according to this system.

Also read - Hutchinson Classification

The system of classification is based on that of de Candolle, but greater stress is being given on the contrast between free and fused petals. The dicots are divided into Gamopetalae, Polypetalae, and Monochlamydeae. The position of Gymnosperms between dicots and monocots is only for convenience rather than an indication of affinities.

An outline of Bentham and Hooker system of classification is given below:

Merits and De-Merits of Bentham and Hooker system of classification:

Merits:

Though this system is not very natural, yet it is very easily workable, and is important from the point of view of its field applications. The system has been figured out as a results of very careful comparative examination of all the known genera of phanerogams.

Also read - ENGLER AND PRANTL CLASSIFIACTION

There are 202 orders (now known as families) beginning with Ranunculaceae and ending in Gramineae. This system was accepted by entire British Empire, U.S.A. and other European countries. Even today many botanists follow this classification due to its simplicity. This classification makes the basis for the arrangement of plants in Kew Herbarium and other important herbaria of Commonwealth Countries.

A special feature of this technique is that the addition of the Disciflorae and a curious arrangement of dividing certain groups on the idea of aquatic or terrestrial characteristics.

In Monocots, the stress is being given to the relative position of ovary and perianth characteristics.

Demerits:

The greatest disadvantage of this technique is that the retention within the group Monochlamydeae, variety of orders which show affinities with those during which a biseriate perianth is that the rule.

The position of Gymnosperms between Dicots and Monocots is only for convenience rather than an indication of affinities.

This system of classification is predicated mainly on single and mostly artificial characters, with the result the closely related families are widely separated from one another .

The extreme simple nature of the parts of certain orders like Salicineae, Cupuliferae, etc.  Such orders would therefore have no near allies in existing orders with an elaborate arrangement of the flower parts.

In Polypetalae, the orders (families) with inferior ovary are placed afterwards, whereas in Gamopetalae they're treated before than those with superior ovary.

In Monocots, much stress is being given to the relative position of the ovary and the perianth characters in determining the affinities, than seems justified by the comparative study of the orders. For example, the families Iridaceae and Amaryllidaceae exhibit greater affinities to Liliaceae than to Scitamineae and Bromeliaceae with which they're allied during this system due to common characters of epigyny.

Thus the treatment of Monocots generally , apart from position of Glumaceae isn't proper.