The earliest systems of classification were derived from the properties
and uses of plants; and it was not until some two centuries ago
that any scientific grouping of plants was attempted. Aristotle and
Theophrastus had adopted the groups of Trees, Shrubs and Herbs as the
chief divisions of the Vegetable Kingdom, a system which persisted
and was employed by Tournefort and Ray as late as the end of the 17th
century. The arrangement by which these three divisions were separated
into smaller divisions was often founded upon a single character, such
as the formation of the corolla, the form of fruit, that of the calyx
and corolla, etc. All these systems of classification which brought
into close proximity plants distinguished by some one character alone,
could only be considered as _artificial_, since plants related to one
another would not necessarily be included in the same group. As the
knowledge of the morphology, physiology, and reproduction of plants
increased, such systems were recognised as unscientific, and it became
the aim of botanists to establish a _natural_ system, founded upon
mutual relationships, which would associate together _only_ those
plants which are truly allied.
The following are some of the chief systems of classification which
will show the gradual development of the natural system, and may be of
service to students making use of this text-book.[41]
System of JOHN RAY (1703).
I. Herbæ.
A. IMPERFECTÆ (Flowerless).
B. PERFECTÆ (Flowering).
_Dicotyledones_.
_Monocotyledones._
II. Arbores.
A. _Monocotyledones._
B. _Dicotyledones._
Ray was the first botanist who recognised the importance of the one
or two seed-leaves of the embryo, and initiated the division of the
Flowering-plants into Monocotyledons and Dicotyledons.
System of LINNÆUS (1733).
In his well known artificial system Linnæus divided the Vegetable
Kingdom into twenty-four classes, based upon the number, relative
position and union of the stamens with regard to each other, and also
to the gynœceum.
Class I. MONANDRIA. Flowers with 1 stamen.
„ II. DIANDRIA. „ „ 2 stamens.
„ III. TRIANDRIA. „ „ 3 „
„ IV. TETRANDRIA. „ „ 4 „
„ V. PENTANDRIA. „ „ 5 „
„ VI. HEXANDRIA. „ „ 6 „
„ VII. HEPTANDRIA. „ „ 7 „
„ VIII. OCTANDRIA. „ „ 8 „
„ IX. ENNEANDRIA. „ „ 9 „
„ X. DECANDRIA. „ „ 10 „
„ XI. DODECANDRIA. „ „ 11 to 19 stamens.
„ XII. ICOSANDRIA. „ „ 20 or more stamens inserted
on the calyx.
„ XIII. POLYANDRIA. „ „ 20 or more stamens inserted
on the receptacle.
„ XIV. DIDYNAMIA. Stamens didynamous.
„ XV. TETRADYNAMIA. „ tetradynamous.
„ XVI. MONADELPHIA. Filaments united into 1 bundle.
„ XVII. DIADELPHIA. „ „ „ 2 bundles.
„ XVIII. POLYADELPHIA. „ „ „ several bundles.
„ XIX. SYNGENESIA. Anthers united together.
„ XX. GYNANDRIA. Stamens and pistil united.
„ XXI. MONŒCIA. Flowers diclinous, ♂ and ♀ on the same
plant.
„ XXII. DIŒCIA. „ „ ♂ and ♀ on different
plants.
„ XXIII. POLYGAMIA. ♂-, ♀-, and ☿-flowers on the same plant.
„ XXIV. CRYPTOGAMIA. Flowerless plants (Ferns, Mosses, Algæ,
Fungi).
These classes were further divided into orders, according to the
number of styles, as Monogynia, flowers with 1 style; Digynia,
with 2 styles, etc. Thus a Dock (_Rumex_), having 6 stamens and
3 styles, would be placed in Class VI., HEXANDRIA, and Order
III., Trigynia.
Class XIV. was divided into two orders. Order I., Gymnospermia,
with seeds apparently naked, comprising the Labiatæ; and
Order II., Angiospermia, with the seeds enclosed in a capsule
(_Bartsia_, _Rhinanthus_).
Class XV. was divided into two orders: Order I., Siliculosa,
fruit a silicula (_Capsella_); and Order II., Siliquosa, fruit a
siliqua (_Brassica_).
Class XIX. was divided into Order I., Æqualis, all the flowers
perfect (_Sonchus_); Order II., Superflua, flowers in the centre
perfect, those at the circumference with pistils only (seemingly
superfluous), _e.g._ _Aster_; Order III., Frustranea, flowers in
the centre perfect, those at the circumference neuter, _e.g._
_Centaurea_.
“Fragments” of a natural system have also come down to us from
Linnæus, who himself always recognised the imperfection of his
artificial system.
System of ANTOINE LAURENT DE JUSSIEU (1789).
Class
=Acotyledones.= Plants without cotyledons: Fungi, Ferns,
Mosses, Algæ, Naiades I.
=Monoctyledones.= Plants with _one_ cotyledon:--
1. Stamens hypogynous II.
2. „ perigynous III.
3. „ epigynous IV.
=Dicotyledones.= Plants with _two_ cotyledons:--
{ Stamens epigynous V.
1. APETALÆ { „ perigynous VI.
{ „ hypogynous VII.
{ Corolla hypogynous VIII.
2. MONOPETALAE { „ perigynous IX.
{ „ epigynous, {anthers connate X.
{ „ free XI.
{ Stamens epigynous XII.
3. POLYPETALÆ { „ hypogynous XIII.
{ „ perigynous XIV.
4. DICLINES IRREGULARES, male and female flowers on different
plants, corolla generally absent.
System of A. P. DE CANDOLLE (1819).
I. =Vasculares.= Plants with vascular bundles.
1. EXOGENÆ. Vascular bundles arranged in a ring.
A. _Diplochlamydeæ._ Calyx and corolla present.
_a._ Thalamifloræ. Corolla polypetalous and
hypogynous.
_b._ Calycifloræ. Corolla perigynous or epigynous;
stamens inserted on the calyx.
_c._ Corollifloræ. Corolla gamopetalous; stamens
inserted on the corolla.
B. _Monochlamydeæ._ Perianth simple.
2. ENDOGENÆ. Vascular bundles scattered, the youngest in
the centre.
A. _Phanerogamæ._ Flowers present.
B. _Cryptogamæ._ Flowers absent.
II. =Cellulares.= Vascular bundles absent.
1. FOLIACEÆ. Leaves present.
2. APHYLLÆ. Leafless.
ROBERT BROWN published in 1827 his discovery of the gymnospermy of the
ovules of the Coniferæ and Cycadeæ, and showed that the Gymnosperms,
which had previously been classed with the Dicotyledons, must be
regarded as an independent group.
System of STEPHEN ENDLICHER (1836–40).
I. =Thallophyta.= No differentiation into stem and root.
1. PROTOPHYTA. Class I., Algæ; Class II., Lichenes.
2. HYSTEROPHYTA. Class III., Fungi.
II. =Cormophyta.= Differentiated into stem and root.
1. ACROBRYA. Stem growing at the point.
_Anophyta_ (Hepaticæ, Musci).
_Protophyta_ (Filices, etc.).
_Hysterophyta_ (Balanophoreæ, etc.).
2. AMPHIBRYA. Stem growing at the circumference
(Monocotyledons).
3. ACRAMPHIBRYA. Stem growing both at the point and
circumference.
_Gymnosperma_ (Coniferae).
_Apetala._ Perianth single or absent.
_Gamopetala._ Petals gamopetalous.
_Dialypetala._ Petals polypetalous.
System of A. BRONGNIART (1843).
I. =Cryptogamæ.= Plants without flowers.
1. AMPHIGENÆ. Not differentiated into stem or leaf (Algæ,
Fungi, Lichenes).
2. ACROGENÆ. Plants with stem and leaf (Muscineæ, Filicinæ).
II. =Phanerogamæ.= Plants with flowers.
3. MONOCOTYLEDONES.
_a._ Albuminosæ. Seeds with endosperm.
_b._ Exalbuminosæ. Seeds without endosperm.
4. DICOTYLEDONES.
_a._ Angiosepermæ.
α. Gamopetalæ.
β. Dialypetalæ.
_b._ Gymnospermæ.
System of JOHN LINDLEY (_Vegetable Kingdom_, 1845).
Asexual, or Flowerless Plants.
Stem and leaves undistinguishable I. =Thallogens.=
Stem and leaves distinguishable II. =Acrogens.=
Sexual, or Flowering Plants.
Fructification springing from a thallus III. =Rhizogens.=
Fructification springing from a stem.
Wood of stem youngest in the centre; cotyledon
single. Leaves parallel-veined, permanent; wood
of stem always confused IV. =Endogens.=
Leaves net-veined, deciduous; wood of the stem,
when perennial, arranged in a circle with a
central pith V. =Dictyogens.=
Wood of stem youngest at the circumference, always
concentric; cotyledons, 2 or more.
Seeds quite naked VI. =Gymnogens.=
Seeds inclosed in seed-vessels VII. =Exogens.=
System of ALEXANDER BRAUN (1864).
I. =Bryophyta.=
1. THALLODEA (Algæ, Fungi, Lichenes).
2. THALLOPHYLLODEA (Charas, Mosses).
II. =Cormophyta.=
1. PHYLLOPTERIDES (Ferns, Equisetums).
2. MASCHALOPTERIDES (Lycopods).
3. HYDROPTERIDES (Water-ferns).
III. =Anthophyta.=
GYMNOSPERMÆ.
1. _Frondosæ_ (Cycadeæ).
2. _Acerosæ_ (Coniferæ).
ANGIOSPERMÆ.
1. _Monocotyledones._
2. _Dicotyledones._
Apetalæ.
Sympetalæ.
Eleutheropetalæ.
W. HOFMEISTER published from 1849 to 1851 his researches upon the
embryology of the Phanerogams, and upon the embryology and life-history
of the Vascular Cryptogams, and established the phylogenetic connection
existing between the Mosses, Vascular Cryptogams and Phanerogams.
System of HOOKER and BENTHAM (_Genera plantarum_, 1862–1883).
Dicotyledones.