SYSTEMS OF BOTANICAL CIASSIFICATION. 



175 



Corolla polypetalous, irregular, composed of five 

 petals, an upper one named the standard, two 

 lateral named the wings, two lower, sometimes 

 united, forming the keel, as in the pea, the kid- 

 ney bean. Lucerne. The fruit is always a le- 

 gume. 



Class XI. Anomalous. — This class contains all 

 the herbaceous plants whose corolla is polypeta- 

 lous, irregular, and not papilionaceous, such as 

 the violet, nasturtium. 



WITH COMPOtJND FLOWERS. 



Class XII. Flosctjlose. — Flowers composed 

 of small, funnel-shaped, regular monopetalous 

 coroUas, having their limb divided into five seg- 

 ments. Each of these small flowers is named a 

 floret. Of this kind are thistles, artichokes, 

 knapweeds. 



Class XIII. Semiplosculose. — Flowers com- 

 posed of a great number of small, irregular mo- 

 nopetalous corollas, whose limb is thrown to one 

 side, and to which the name of semiflorets has 

 been given, as the lettuce, the goatsbeard, the 

 dandelion. 



Class XIV. Radiate. — Flowers composed of 

 florets at the centre, and semiflorets at the cir- 

 cumference, as in the sunflower and the daisy. 



APETALOUS PLANTS, 



Class XV. Apetalous. — ^Plants whose flowers 

 have no true corolla, as the grasses, barley, rice, 

 the oat, wheat. In some there is around the 

 sexual organs a simple perianth or calyx, which 

 often remains after the flowering is over, and 

 grows with the fruit, as in docks. 



Class XVI. Apetalous, entirely destitute of 

 flowers. — Plants which have no sexual organs or 

 floral envelopes properly so called, but which 

 have leaves. Of this kind are the ferns, such as 

 polypody, osmunda. 



Class XVII. Apetalous, without apparent 

 flowers or fruit, as mushrooms, mosses, lichens. 



SECOND DIVISION.— TREES. 



Class XVIII. Apetalous Trees or Shrubs, 

 having their flowers destitute of corolla. These 

 trees are either hermaphrodite or monoecious, as 

 the box, many coniferae, &c.; or dioecious, as in 

 the genera terebinthiis, and lentiscus. 



Class XIX. Amentaceous. — Apetalous trees, 

 whose flowers are disposed in catkins. They are 

 monoecious, as the oak, the walnut ; or dioecious, 

 as the willows. 



Class XX. Trees with a regular or irregular 

 monopetalous coroUa, such as the lilac, the elder, 

 the catalpa, the arbutus. 



Regular polypetalous. 

 Class XXI. Trees or shrubs with rosaceous 

 polypetalous corolla, as the apple tree, the pear 

 tree, the orange and cheny tree. 



Irregular polypetalous. 

 Class XXII. Trees or shrubs whose corolla 

 is papilionaceous, as in the acacia and laburnum. 



Such are the twenty-two classes proposed by 

 Tournefort for the arrangement of all known ve- 

 getables. Although, at first view, this system 

 may appear simple and easily reducible to prac- 

 tice, it yet in many cases presents difficulties 

 which are not easily overcome. Thus the form 

 of the corolla is not always so decided as to en- 

 able one immediately to determine the class to 

 which it really belongs ; for where is the precise 

 point of separation between a hypocrateriform 

 and an infiindibuliform corolla, or between the 

 latter and a campanulate corolla ? 



The greatest objection that can be offered to 

 this system is, that it separates the herbaceous 

 from the woody plants. The most natural rela- 

 tions are by this means mistaken, and plants 

 which bear the greatest resemblance to each 

 other are often widely separated, on account of 

 their difi^ring in this respect only. 



Each of these classes has been subdivided into 

 a greater or less number of sections or orders, 

 whose characters have been taken from particu- 

 lar modifications which the form of the corolla 

 may undergo, from the consistence, composition, 

 and origin of the fruit, the form, arrangement, 

 and composition of the leaves. 



Moreover, each of these sections contains a 

 greater or less number of genera, to which are 

 referred all the species that were known up to 

 the period at which Tournefort wrote. 



The sexual system op Linn^us is principally 

 founded on the diflferent characters which may 

 be derived from the male organs or stamina, ia 

 the same manner as Toumefort's system isfounded 

 upon the various forms which the corolla pre- 

 sents. It consists of twenty-four classes. 



LrnnsBus first divides all the known vegetables 

 into two great sections. In the first he places 

 all those which have sexual organs, and conse- 

 quently distinct flowers. These are the phan- 

 erogamous or phaenogamous plants. The second 

 section comprehends those in which the sexual 

 organs are not apparent, or in which they are 

 entirely wanting. There are thus two primary 

 sections in the vegetable kingdom : — 



1. Phanerogamous plants. 



2. Cryptogamous plants. 



But, as the number of vegetables belonging 

 to the first section is infinitely greater than 

 that belonging to the second, the phanerogamous 

 plants have been divided into twenty three classes 



