This
is the phylogenetic system of classification forwarded by an English botanist Adolf Engler (1844-1938), which was
published as a guide to the Botanical
Garden of Breslau from
1889-1921. The system was published in expanded and elaborated form in “Die Naturlichen Pflanzebfamilian” in 23
volumes, covering the whole range of plant kingdom, under the editorship of
Engler and his associate Eugen Prantl
(1849-1893).
In
this system, the families were arranged according to the increasing complexity
of the flower, fruit and seed development. In this system, flowering plants
have been divided into 2 Sub-divisions.
Sub-division I: Angiospermae
Sub-division
II: Gymnospermae
Angiospermae
is divided into 2 Classes –
Class
1: Monocotyledonae – It has been
directly divided into 11 Orders with
45 families. The first order is Pandanales and the last is Microspermae (ending family
Orchidaceae).
Class
2: Dicotyledonae – It is sub-divided into 2
sub-classes.
Sub-Class
I: Archichlamydeae – It contains 33 Orders and 190 Families. The first order is Verticillatae and the last is Umbelliferae.
Sub-Class
II: Metachlamydeae or Sympetalae –
It contains 11 Orders and 53 Families. The first order is Ericales and the last is Campanulatae.
In Engler and Prantl’s system of
classification, there are altogether 288
families. Monocotyledoneae
begins with the family Typhaceae and
ends with Orchidaceae. Dicotyledoneae begins with the family Casuarinaceae and ends with Compositae.
A synoptic outline of Engler & Prantl’s system of classification is as follows –
Phanerogams or
Seed Plants
(2 Sub-divisions)
|
|||
Sub-Division 1: Angiospermae
(2 Classes)
|
Sub-Division 1: Gymnospermae
|
||
Class 1: Monocotyledoneae
(11 Orders & 45 Families)
|
Class 2:
Dicotyledoneae
(2 Sub-Classes)
|
||
Sub-class 1:
Archichlamydeae
(33 Orders & 190 Families)
|
Sub-class 2:
Sympetalae
(11 Orders & 53 Families)
|
||
Order
1: Pandanales
|
Order
1: Verticillatae
|
Order
1: Diapensiales
|
|
Order
2: Helobiae
|
Order
2: Piperales…...
|
Order
2: Ericales
|
|
Order
3: Triuridales
|
Order
13: Urticales….
|
Order
3: Primulales
|
|
Order
4: Glumiflorae
|
Order
16: Santanales …..
|
Order
4: Plumbaginales
|
|
Order
5: Principes
|
Order
19: Polygonales…..
|
Order
5: Ebenales
|
|
Order
6: Synanthae
|
Order
21: Ranales…….
|
Order
6: Contortae
|
|
Order
7: Spathiflorae
|
Order
24: Rosales ……
|
Order
7: Tubiflorae
|
|
Order
8: Farinosae
|
Order
27: Sapinadales …..
|
Order
8: Plantaginales
|
|
Order
9: Liliflorae
|
Order
29: Malvales……
|
Order
9: Rubiales
|
|
Order
10: Scitamineae
|
Order
30: Parietales ……
|
Order
10: Cucurbitales
|
|
Order
11: Microspermae
|
Order
33: Umbelliflorae
|
Order
11:Campanulatae
|
|
MERITS
AND DEMERITS OF ENGLER & PRANTL’S SYSTEM OF CLASSIFICATION
MERITS
(a) This is very
convenient and well-known filing system of several herbaria of the world.
(b) Gymnosperms
have been treated separately.
(c) This system
treated families, such as Orchidaceae and Compositae, as advanced families.
(d) In this
system, several closely related families (e.g. Liliaceae, Juncaceae, Iridaceae and
Amaryllidaceae) are treated close to one another.
(e) Abundant
illustrations are provided along with the description of the families.
(f) The system is
provided with exhaustive keys of families and orders.
(g) The
description of families also contains a summary of embryology, morphology,
anatomy and geological distribution.
DEMERITS
(a) Monocots have
been considered more primitive than dicots in this system.
(b) The position
of Amentiferae at the beginning of dicots before Ranales is unsatisfactory.
(c) Helobiae,
consisting of primitive forms, have been placed between two advanced orders Glumiflorae
and Pandanales.
(d) Araceae are
derived from Liliaceae, but Engler and Prantl places Araceae before Liliaceae.
************
No comments:
Post a Comment