1. Bentham & Hooker System of
Classification
Dr.Sujit Ghosh
J K College
Purulia
2. George Bentham a great taxonomist and plant explorer Sir
Joseph Dalton hooker a great plant geographer and English
systematizes jointly presented a system of classification. Their
classification was published in 3 volumes of genera plantarum.
They are associated with royal botanical garden at kew and
adopted a very comprehensive system of classification which is
purely natural and most convenient and extremely suitable system
for practical utility in identification of plants providing them, their
respective taxon. Following discussion can prove this fact.
3. Main features of classification :
i) This system includes the names and descriptions of all genera, of seed plants
known so far and classified accordingly.
ii) This system divided seed plants into 97,205 species under 202 order or
families.
iii) They divide seed plants into three classes in sequence. Discotyledon,
gymnosperm and monocotyledon.
iv) Dicots divided into 3-divisions and 14 series on the basis of the natural and
visual characteristic which provides key for identification.
v) Diocts started with family Ranun Culaceae having free sepals and petals and
indefinite number of stamens and carpels are free where as it ends with
labiatale having fused sepals and petals with definite number of carpels and
stamens.
vi) Among monocots out of seven series with epigenous flower i.e.
orchidaceous and scitaminal were kept first and second respectively followed
by with petaloid hypogenous flowers and finally ended with Graminae and
Cyperaceous.
4.
5. Division – II Gamopetalae :
Petals united, Flowers with distinct calyx and corolla. Stamens
few, attached to corolla lobes.
Class – II (Group) Gymnospermae:
Flowers in cones, perianth absent, seed not enclosed by fruit
or Pericarp. It includes 3 orders.
Class – III (Group) Monocotyledon :
Usually herbs, some are shrubs, seed with one cotyledon
inembroyo.
It includes seven series, viz moscrospermae, Epigynae,
Nudiflora, glumaceae etc.
6. From this classification it is understood that if we proceed from the beginning
considering the morphological characters of a species we can easily identify it
to place it in its specific taxon. Therefore this classification is widely used in all
over the world herbaria for following reasons.
i) Every genera and species was studies from the actual specimens
available in the British and continental herbaria and their descriptions were
based on their detailed morphological studies and dissections of flowers.
ii) Description made in classification for each taxon based on actual
examination of species.
iii) In the division polyetalae the new series disc florae is interpolated
between, thalmin flora and caliciflorae of Decandle’s system and it is a
refinement over Decandole’s classification.
iv) Cymnosperms placed as a third taxon and placed in between dicot and
monocot.
v) Ranales is placed first in the dicot which is very reasonable.
vi) Monocot follow dicots, but the gymnosperms in between is anomally but
it is justified.
vii) Monochlamydae is considered as highly evolved and polyetalae is the
most primitive.
Thus Bentham and Hooker’s system of classification is a natural system and
there is no doubt that it provides a key for identification of plants.
