Lives of Eminent Zoologists, from Aristotle to Linnus

Page 58 of 79

Division I. Herbs.

* With simple flowers.

Corolla of one piece, regular.

Class I. Campaniformes, with a regular corolla, of one piece, and resembling a bell; as the convolvulus.

II. Infundibuliformes, with a regular corolla, of one piece, and resembling a funnel; as the tobacco.

Corolla of one piece, irregular.

III. Personatæ, with an irregular corolla, of one piece, resembling an antique mask; as the foxglove.

IV. Labiatæ, with an irregular corolla, of one piece, divided into two lips; as the sage.

Corolla of several pieces, regular.

V. Cruciformes, with a regular corolla, composed of four petals, placed crosswise; as the wallflower.

VI. Rosaceæ, with a regular corolla, composed of several petals, arranged in the form of a rose; as the wild rose and apple.

VII. Umbelliferæ, with a regular corolla, composed of five petals, the flowers arranged on stalks resembling the spokes of an umbrella; as in the carrot.

VIII. Caryophylleæ, with a regular corolla, composed of five petals, having long claws; as the pink.

IX. Liliaceæ, with a regular corolla, composed of six or three petals, or sometimes of one piece with six divisions; as the tulip.[Pg 294]

Corolla of several pieces, irregular.

X. Papilionaceæ, with an irregular corolla, composed of five petals; as the pea.

XI. Anomalæ, with an irregular corolla, composed of five petals, but differing from the papilionaceous form; as the violet.

* * With compound flowers.

XII. Flosculosæ, with flowers composed of small funnel-shaped, regular corollas, divided into five segments; as the thistle.

XIII. Semiflosculosæ, with flowers composed of small irregular corollas, of an elongated flat shape; as the dandelion.

XIV. Radiatæ, with flowers composed of funnel-shaped florets at the centre, and flat ones at the circumference; as the daisy.

* * * Destitute of flowers.

XV. Apetalæ, whose flowers have no true corolla; as the grasses.

XVI. Apetalæ, entirely destitute of flowers, but having leaves; as the ferns.

XVII. Apetalæ, without apparent flowers or fruit; as mosses.

Division II. Trees.

Without petals.

XVIII. Apetalous Trees or Shrubs, having their flowers destitute of corolla; as the box.

XIX. Amentaceæ, with the flowers disposed in catkins; as the oak.

With flowers of one petal.

XX. Trees with a regular or irregular corolla of one piece; as the lilac.

With regular flowers of several petals.

XXI. Trees or Shrubs with rosaceous corolla; as the apple-tree.[Pg 295]

With irregular flowers of several petals.

XXII. Trees or Shrubs with papilionaceous corolla; as the laburnum.

Each of these classes is subdivided into various sections or orders, founded upon modifications in the form of the corolla, the nature of the fruit, the figure of the leaves, &c. The sections contain a greater or less number of genera, under which are disposed all the species known to the author.

This classification was of the greatest service to botanists; though it was, like every other method that had been proposed, defective in many respects. A great objection to it is, that it separates the herbaceous from the woody plants, thus tearing asunder the most natural connexions; nor is the form of the corolla always so determinate, that one can say whether it be bell-shaped, funnel-shaped, or salver-shaped,—a point which it is necessary to decide before the species can be made out. Various changes were soon proposed, and new methods planned, so that the science was again falling into confusion, when Linnæus published his system, which was presently adopted by many teachers, and long before his death was in general use.

He made the stamina and pistils the basis of his arrangement, which he was induced to do from the consideration of their great importance, as the parts most essential to fructification. These organs being analogous to those distinguishing the sexes of animals, the Linnæan method is sometimes called the sexual system. It consists of twenty-four classes. The first ten are determined by the number of the stamina.

Class I. Monandria, containing all plants of which the flowers have only one stamen; as the mare's tail.[Pg 296]

II. Diandria: two stamens; as the jasmine.

III. Triandria: three stamens; as wheat, oats, and grasses in general.

IV. Tetrandria: four stamens; as woodruff.

V. Pentandria: five stamens; as the primrose.

VI. Hexandria: six stamens; as the lily and tulip.

VII. Heptandria: seven stamens; as the horse-chestnut.

VIII. Octandria: eight stamens; as the heaths.

IX. Enneandria: nine stamens; as rhubarb.

X. Decandria: ten stamens; as the pink.

In the next three classes, the stamens exceed ten in number, but differ from each other in certain circumstances.

XI. Dodecandria: stamens from twelve to twenty; as in agrimony.

XII. Icosandria: twenty or more stamens, inserted upon the inner side of the calyx; as in the rose and apple.

XIII. Polyandria: twenty or more stamens, inserted upon the receptacle or point of union of all the parts of the flower; as in the crowfoot and anemone.

The relative length of the stamens determines the next two classes.

XIV. Didynamia: four-stamens, of which two are shorter; as in thyme and foxglove.

XV. Tetradynamia: six stamens, of which two are shorter; as in cabbage and wallflower.

Three classes are indicated by having the stamina connected by their filaments.

XVI. Monadelphia: stamens united by their filaments into a single body or set; as in mallows.

XVII. Diadelphia: stamens united into two distinct sets; as in fumitory.[Pg 297]

XVIII. Polyadelphia: stamens united into three or more bundles; as in hypericum and cistus.

In the next class, the stamens are united by their anthers.

XIX. Syngenesia: five stamens united by the anthers; as in the dandelion and violet.

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