366
I
■t i
lines on the page opposite the catalogue lines, as in Galpine’s Compendium o f the British
Flora. It miglit fa.rtlicr, by subjoining notes to all the useful or remarkable species at
the bottom of every page, be rendered a history of plants, including their uses in the
arts and manufactures, and their culture in agricultui-e and gardening. Such a work is
our Eneyclopeedia o f Plants, haidng, iu addition, engravings of one or more species O’f
all the different genera.
Ciï4\p. m .
Taxonomy, or the Classification o f Plants.
1003. Without some airangement, the mind o f man would be unequal to the task o f
acquiring even an imperfect knowledge o f the various objects o f naiure. Accordingly, in
every science, attempts have been made to classify the different objects that it embraces,
and these attempts have been founded on various principles. Some have adopted
artificial characters ; others have endeavoured to detect the natural relations of the beings
to be aiTanged, and thus to ascertain a connection by which the whole may be associated.
“ It was fonnerly supposed,” Lindley observes, “ that the organs of fructification were
more constant iu tlieir chai-acter, and less subject to variation, than any other part of the
plant ; and hence they were exclusively adopted as a means of classification. But
modern investigations have shown that characters drawn from the mode in which plants
grow, and from certain anatomical peculiarities, are of much higher value ; so that tho
organs of fiuctification arc now chiefly employed for the distinction of genera, or of
orders and tribes. And, even in these minor groups, the organs of vegetation are frequently
of high importance.” (Lindl. Introd., 1st ed., p. 308.)
1004. The earliest systems o f classification must have been perfectly natural ; as the
first step, after giving names to plants to distinguish them from each other, must have
been to class them rudely together. As Dr. Lindley observes, “ plants must have
yielded man his earliest food, and his first built habitation. Their general use could
not fail to produce experience, and especially the art of distinguisliing one kind of plant
from another, if it were only as a means of recognising the useful and the worthless
species, or of remembering those iu which such qualities were most predominant. Tliis
would involve from the very beginning the contrivance of names for plants, togethei-
witli the collection of individuals into species ; and the mental process by which this
was unconsciously effected, gi-adually ripened into the first rude classifications we know
of. By placing togethei- individuals identical in form and the uses to wliich they could
bo applied, species were distinguished ; and by applying a similar process to the species
themselves, groups analogous to what we now call genera were obtained. The last
step was to constitute classes, which were recognised under the well-known names of
‘ gi-ass and herbs yielding seed, and frait trees yielding fruit.’ ” (Lindleÿs Vegetable Kingdom,
Introd. p. xxii.)
1005. The first writers on hotany, such as Theophrastus, &c., grouped their plants
according to their habits and nature ; placing together the water plants, parasites, forest
trees, &c. ; and our earliest English writers on plants, such as Gerard and Parkinson,
adopted a similar method of an-angemcnt. Fuchsius and some other miters, on the
contrary, classed thcir plants from their use in medicine, placing those they called hot
apart from those they called cold. The first of these methods, that of classing plauts
according to thefr habit of growth, had certainly many advantages in helping persons
but little acquainted -vvith horticultm-e to araange their gardens ; and the classing of
plants according- to thefr medicinal qualities must have been of great use at the time
when plants were principally cultivated for their application in medicine. Our ancestors
appeal- to have liad very little idea of cultivating plants for the beauty of their flowers,
and the first gardens that did not consist merely of culinai-y fraits and vegetables were
simply, as, indeed, they were called, physic gardens, that is, gardens in which the plants
used in medicine were collected, partly that they might be ready when wanted and
partly that students studying medicine might see them, and become acquainted with
their foi-ms. The botanic garden at Chelsea was a garden of this kind, established by
the Apotliecaries’ Company for the use of young men who intended to become
apothecaries ; and the botanic gardens at Oxford and Cambridge were for students in
medicine at the Universities. When chemistry was comparatively little known, mineral
remedies were looked upon with dread, while vegetable medicines were in constant use.
I t was natural, therefore, that the earlier botanists should class plants together by tlieir
medicinal qualities ; but the modes of classification were so vague, from the great number
of plants tliat possessed nearly the same quality, that the classification was of little use,
unless it was accompanied by long verbal descriptions ; and it was partly the trouble
occasioned by these long descriptions that made the system of Linnæus be so eagerly
accepted by all scientific men. The great Swede swept away the whole of the verbiage
which he found encumbering botany ; he invented specific names to express iu one word
what Ins predecessors had employed a sentence to explain; aud he limited his Latin
specific distinctions to twelve words.
1006. Artificial Systems arose from its being found necessarj- to have some definite
modes of distinction ; when, as Dr. Lindlcy obsen-es, “ botanists set themselves to work
to chscover some method of arrangement, that should he to Botany what the alphabet
IS to language, a k e y hy wlfich the details of the science may be readily ascertained.
WitJi this in view, Rmn u s invented, in 1690, a system depending on the foi-mation of
the coroUa ; Kamel, m 1693, upon the fruit alone; Magnol, in 1720, on the calyx and
coroU^_and finally Linnæus, in 1731, on variations in the stamens and pistil.” (Lm d l
Veg King., Introd. p. xxiii.) AH these systems, however, are liable to the very great
and insurmountable objection, that, depending on a single featui-e, they become uncertain
It that feature should chance to be altered, as it often is, by any accidental circumstance
arising from the sod, situation, weather, &c. Thus, for instance, when the artificial
a-nangement depends upon the corolla, if from a vei-y di-y season, or any other cause
tlie flower happens to be distorted, it becomes impossible to recognise the species.
1007. ih e Natural System depends not upon the resemblance of plants in one par-
frcular featui-e, but upon thefr general resemblance in stracture, habits, and qualities.
Ray, who appears to have had the first clcai- idea of a natural system, defines it to be
one ™ c h n p th e r brings together dissimilar species, nor separates those which arc
nearly allied ; _ and Jussieu says, that as a species “ consists of individuals very much
alike in all then- parts, and retaining thefr resemblances from generation to generation”
(Ibid. p. 3^v.), so a group of species combined upon the same principle forms a genus
a gi-oup of genera an order, and a gi-oup of orders a class.
1008. The points o f resemblance between plants which constitute their affinity according
to tke Natural System are, however, very difficult to define. In fact, as Dr Lindlev
obsci-ves, “ very different ideas of lilceness and imhkcness arc entertained by different
obsei-vers. The common people can see no difference of moment between a daplmc
a cherry, and a rhododendron, but call them all laurels, altliougli a botanist fafls to
perceive their resemblance. On the other hand, there seems to the vulgai- eye no connection
between the hcipp-plant and the mulberry-tree, and yet the botanist brings
them into close alliance. Nor are these conflicting views confined to the ignorant and
the uneducated ; such differences of opinion may he found among botanists themselves ”
( Vegetable Kingdom, p. xxv.)
1009. The object o f all methods o f classification is to promote a knowledge of plants
by rendering it easy to discover their names and qualities. The Linnæan system is
generaUy considered the best for discovering the names ; as plants classed hy it have
been compared to words in a dictionaiy. Plants classed according to the natm-al
metliod have, on the contrary, been compai-ed to words an-anged according to tlieir
roots or derivations ; and hence, when their names are discovered the smdent acquires
at the same time a general idea of thcir constniction and functions, as well as their
a Iiances with other plants. I t is, however, (piite as easy to discover to what order a
plant belongs by the natural as by the Linnæan system ; as gencraUy all plants belonging
to the same natural order bear a certain degree of resemblance to each other which
makes it easy to recognise them at first sight. As a proof of this, we need onlv
suppose that a new plant has been introduced, of which it is wished to discover the
nanie. We wiU suppose that it belongs to the genus J/ypcricum, as this genus is-
particuhudy ea^sy to be discovered by a Linnæan botanist, on account of its b?ing the
only Bntirii plant which has polyadelphous stamens, that is, the stamens in distinct
bundles. Tlie Linnæan botanist, however, can only ascertain this fact when he secs the
flower, and consequently it is only dui-ing the flowering season, or, in other words
dm-ing only a very few weeks, that he has any chance of discovering that the plant
be ongs to tfro genus finséricmn ; whereas the student in the Natural System med
only hold a leaf up to the light, when he will find that it is full of ceUs containino- a
yellow nonodorferous liquid, and he will know immediately that the plant must“ bo
some kuid of iip e n e um . Tins is a yery great adyantage, as the flowering season is
confined to so short a period of the yeai-.
Sect. I. The Linncean Arrangement.
1010. The main object o f all artificial systems o f botanical arrangement is to fecilitate
the discovery of the names of plants. For this puiiiose some one organ, common to
plants in general, is fixed on ; and, according to certain conditions in which this ora-an
is found, individual species are refeiTcd to thefr places in the system, as words, by their
iiiitial frttem, arc rcfcn-cd to thcir places in an alphabetical dictionaiy. In the progress
of artificial systems, diflhrent organs have been fixed on by different botanists ; bun
tliose which have been most extensively employed are the corollas by Tournefort and