1. Polygamia ^Equalis. In this Order, all the florets 



are equally possessed of stamens and 

 pistils ; as the Dandelion. 



2. Polygamia Superflua. The florets of the disk, or 



central part of the flower, have both 

 stamens and pistils ; those of the ray, or 

 circumference, have only pistils : but the 

 latter, as well as the former, produce 

 fertile seeds ; as the China Aster. 



3. Polygamia Frustanea. The florets of the disk have 



both stamens and pistils ; those of the 

 ray neither one nor the other, or are only 

 abortive pistils ; as the Sun Flower, 

 Arkansa coreopsis, &c. 



4. Polygamia Necessaria. The florets of the disk have 



efficient stamens, but abortive pistils ; 

 those of the ray, fertile pistils, impreg- 

 nated by the stamens of the disk ; as 

 the Marigold, or Calendula. 



5. Polygamia Segregata. Distinguished by its doubly 



compound flowers, each floret having 

 its own calyx, in addition to that which 

 surrounds the common receptacle, and 

 forms the whole into one compound 

 flower ; as in the Globe Thistle. 



20. 21. Classes. In these, the Orders have the same 

 names as the preceding classes, and are distin- 

 guished by the number of stamens, or by the 

 union either of the filaments, or of the anthers, 

 or by the attachment of the stamens to the pis- 

 tils. 



22. This Class has 8 Orders the first seven deno- 



minated from the number of stamens. The 

 eighth order, Monadelphia, by the stamens being 

 united into one set ; as the Juniper, Yew, &c. 



23. The Order, denominated from the number of the 



houses, or plants, on which the several kinds of 

 flowers are to be found. It has three Orders : 

 Monoscia, when the stamens and pistils are in 

 separate flowers, but on the same plant. Diaecia, 

 having the stamniferous and pistiliferous flowers 

 on two separate plants. And Tricecia, when the 

 different kinds of flowers are distributed among 

 three distinct individual plants. 

 Linn&us devoted the greater part of his life to the study 



of Botany. He was the first who pointed out the difference 

 between the natural and the artificial method of arrang- 

 ing plants. His sexual system is an example of the latter, 

 though many of its Classes, or Orders, happen to be like- 

 wise natural assemblages. 



Many systems of classification have since been at- 

 tempted, but, notwithstanding the acknowleged merit of 

 these essays, the Linnsean system continues to be the 

 prevailing system, to which all the new Genera, consti- 

 tuted for plants since discovered, are regularly referred. 

 And it is to the advantage of the science, that it should, 

 for a long time yet to come, preserve its ascendency. 



It is the system of Linnaeus that has chiefly been 

 adopted in this little compilation. 



Bernard de Jussieu, the father of the French botanists, 

 deterred, by excess of modesty, from giving his ideas to 

 the world, was the first who laboured at a natural system 

 of arrangement. 



It was not before the year 1759, when he was called up- 

 on, as Professor of Botany, to arrange the royal garden at 

 Trianon, that he ventured to give any publicity to the 

 natural system he had been projecting. What this was, 

 may be seen by his nephew Antony de Jussieu's Genera 

 Plantarum, published in 1789. Bernard de Jussieu be- 

 came acquainted with Linnaeus at Paris, in 1738, and was 

 quite aware of his merits, and disposed to allow them. 



The Natural Orders, as arranged by A. de Jussieu from 

 his uncle's works, are also given in the glossary to this 

 work: he has fifteen Classes, and a hundred Orders. His 

 Orders are mostly named from some leading Genus, which 

 appears to me to be a more satisfactory arrangement. 



Natural Orders of plants are such as are founded on 

 principles of natural affinity ; bringing together, under 

 one point of view, such Genera as have certain characters 

 in common, independent of all artificial modes of classi- 

 fication. 



In the conception of his Orders, Linnaus ever kept the 

 fructification principally in view, though the names of 

 some few of them allude to the habit. 

 There are fifty-eight Natural Orders of Linnaeus. 



NATURAL ORDERS OF LINN^US. 



1. PalmcE Palm Trees. 



2. Piperitce Arum and its allies. 



3. CalamaritB Grass-leaved plants, as Carex. 



