Polypetaloe, Perigynse and Epigynse; and Epigynse antheris oonnatis. 3d. Corollifiora;
equivalent to Monopetala: hypogyna, and 4th. Monochlamydece, including all thoBe orders
in which the corolla is wanting. It is the third of these sub-classes we are now about
to consider which includes, in his work, a continuous series of nearly 40 orders, without
sub-division or grouping to assist us in referring any unknown plant to the order to which
it belongs.
Endlicher and Meisner both follow Jussieu in assigning a high value to the corolla
their leading divisions in the distribution of their groups being, Apetalous, Monopetalous*
and Polypetalous.
Lindley, on the other hand, in his last work, “The Vegetable Kingdom,” altogether
rejects the form of the corolla as an element in his general arrangement, adopting insertion
alone as his basis, three of his four sub-classes of Exogens being respectively
designated Hypogynous Perigynous and Epigynous Exogens, the superstructure of which is
composed of “Alliances” not unfrequently made up of a group of orders in which apetalous,
monopetalous and polypetalous families combine to form his circle, if the term be allowable!
How .far science is to be benefited by this change remains to be ascertained. As it
now stands, the advantage derived from it does not strike me as being by any means
obvious, since the basis is nearly, if not to the full, as artificial as that of the old arrangement,
and liable to nearly as great variations, even in the same orders, while many of
the alliances include orders greatly at variance with their essential characters. See, for
example, OleacecB in Solanales. But still, as such defects seem unavoidable, in the present
state of our knowledge, I do not attach much importance to them and view his
arrangement, as a whole, as a great step in the right direction, and have no doubt it
will ere long prove a sure guide to a more perfect distribution, by leading to the discovery
of a broad and natural basis on which to construct our natural system, and
supersede the narrow and artificial one on which the noble edifice now stands.
Hitherto I have followed De Candolle’s arrangement as my guide and, for obvious
reasons, wish and intend to do so still. As, however, he has not thought fit to lighten
the labour of investigating the orders of this extensive sub-class by distributing them
into minor groups, either artificial or natural, 1 propose, by way of introduction to its
study, to submit outlines of two schemes proposed for this purpose, each of which furnishes
a conspectus of the orders, but constructed on somewhat different principles and
occasionally leading to different results. The first was prepared by Dr. Arnott, Professor
of Botany in Glasgow, the other by myself.
They are both, to a greater -or less extent, artificial, but being different, may probably
mutually assist each other in enabling the young Botanist to determine the order
to which any unknown plant under examination may belong, and they both possess the
charm of novelty, if that is any advantage, as neither has yet been published. In regard
to Dr. Arnott’s arrangement, it is necessary to guard against compromising him by allowing
the reader to suppose for a moment that the accomplished Author considers it a
perfect or final one. He thus writes, “The order I at present adopt in my syllabus for
my class, is to divide Corolliflorce into groups, perhaps too artificial, but of great use to
students [the thing wanted here]. Perhaps I shall have to alter much of it when I have
more time to study. I drew up the short characters to chalk on the board last summer
when much hurried.”
In regard to my own, it was prepared solely for this work, I fear also rather hur-
r*e<^£.’ | | | | be found useful as an aid to the other, as being constructed on
a different basis and associating different orders in the groups. Mine only includes the
Indian orders.
A glance at our respective schemes will show that, notwithstanding the alleged badness
of characters taken from the corolla, we coincide in viewing the sub-class, Coroll i-
florje, as a large and, upon the whole, natural assemblage of orders which it is necessary
to divide and classify into minor groups, to .facilitate their investigation and discrimination.
For this purpose, apparently, as furnishing more obvious characters, Dr. Arnott
usually assigns the first place to the flower and its parts and has recourse to the ovary,
fruit, and vegetation for secondary ones. I, on the other hand, on the supposition that
the ovary and fruit furnish more constant and, in the main, more valuable ones, though
less easily investigated, give them the first place in my classification.
The labour of investigation is the same, as it is equally indispensable, in both, that
the structure of the ovary, seed-vessel, and seed should be known before determinate results
can be arrived at, but the result is different. I do not venture to decide whose
groups are the most natural, in the cases where they materially differ.
DR. ARNOTT’S SYLLABUS.
Group I. Ovary compound, of 4 or more carpels, 1- or several-celled (rarely inferior).
Petals sometimes distinct from each other (or none). Stamens opposite the petals
(alternate. with the sepals), and of the same number, with or without the alternate
sterile ones.
P rimulacejE. Placenta large, central, free. Herbs.
Myrsiniace^e. Placenta central, free. Woody plants with linear transparent dots in
the leaves.
Sapotace^e. Ovary several-celled. Woody plants.
Group II. Flowers regular. Stamens more than two, alternate with the segments of
the corolla and isometrical or more numerous. Ovary superior, cells isometrical with the
sepals. Ovules solitary, in each cell, or in pairs, pendulous. Woody plants.
iLiciNEiE. Stamens as many as the petals. Stigma nearly sessile.
E benac/E. Stamens two or more times as numerous as the sepals* Style conspicuous.
Group III. Flowers regular. Ovary usually inferior of several cells. Stamens numerous,
inserted on the corolla.
STYRACACEiE. (This being the only order of the series with inferior fruit, no ordinal
character is required.)
Group IV. Flowers regular, stamens 2 [or 4, usually] fewer than the segments of
the corolla. Ovary superior or nearly so, 2-celled, petals sometimes wanting, ovules solitary
or in pairs. Leaves opposite. [I have introduced the words within the brackets for
the purpose of making room for Azimacece, which clearly belongs to this group, in every
thing except the number of stamens; but for them and its very distinct habit, it might
be admitted into the tribe Chionanthece of Oleacea.]
J asamineje. Ovules erect or ascending, seed with little or no albumen, corolla decidedly
gamopetalous.
Oleace*:. Ovules pendulous. Seeds with copious albumen. Corolla (sometimes wanting)
sub-4-petalous.
AziMACEiE. Ovules erect. Flowers sub-4-petalous. Stamens isometrical.
Group V. Flowers regular or nearly so. Stamens isometrical with the lobes and alternating
with them (if in-isometrical the leaves are stipuled). Carpels 2, more or less combined.
Stigma short. Leaves opposite.
Asclepiadea:. Ovaries distinct. Stigma 1, dilated (with 5 corpusculiferous angles),
pollen cohering in masses. Stipules none.
ArocYNEiE. Ovaries distinct or united. Stigma 1, contracted in the middle. Pollen
pulverulent. .Estivation twisted.