Boox I. NAMES OF CLASSES, ORDERS, AND GENERA. 



Chap, III. 



Pki/tograpky, or the Noinendature and Description of Plants. 



557. The whole vegetable kingdom is divided into classes, orders, genera, species, and 

 varieties. A class is distinguished by some character which is common to many plants ; 

 an order is distinguished by having some character limited to a few plants belonging to a 

 class ; a still more limited coincidence constitutes a genus ; and each individual of a 

 genus, which continues unchanged when raised from seed, is called a species. A variety 

 is formed by an accidental deviation from the specific character, and easily returns by seed 

 to the particular species from which it arose. 



558. Before botany became a regular science, plants were named as individual beings, 

 without regard to any relation which they had to one another. But from the great num- 

 ber of names to be retained on the memory, and the obvious aflfinities existing among 

 certain individuals or natural families, some method was soon found necessary, and it 

 was then deemed requisite to give such composite names as might recall to mind some- 

 thing of the individuals to which they were applied. Thus we have Anagalis fore cceruleo. 

 Mespilus aculeata jiyrifolia, &c. But in the end the length of these phrases became in- 

 convenient ; and Linnseus, struck with this inconvenience, proposed that the names of 

 plants should henceforth consist of two words only, the one the generic or family name, 

 and the other the specific or individual name. 



559. The names of classes and orders were originally primitive, or without meaning, as 

 the Grasses of Tragus, Poppies of Bauhin, &c. j and afterwards so compounded as to be 

 long and complex, as the PolloplostemonopetalcB, Eleutheromacrastemones, &c. of Wachen- 

 dorf. Linnaeus decided, that the names of classes and orders should consist of a single 

 word, and that word not simple or primitive, but expressive of a certain character or 

 characters, found in all the plants which compose it. 



560. In applyijig the names to plants, three rules are laid down by botanists : 1st, That the 

 languages chosen should be fixed and universal, as the Greek and Latin ; 2d, That these 

 languages should be used according to the general laws of grammar, and compound 

 words always composed from the same language, and not of entire words, &c. ; 3d, That 

 the first who discovers a being, and enregisters it in the catalogue of nature, has the right 

 of giving it a name ; and that that name ought to be received and admitted by naturalists, 

 unless it belong to a being already existing, or transgress the rules of nomenclature. 

 Every one that discovers a new plant may not be able to enregister it according to these 

 laws, and in that case has no right to give it his name ; but the botanist who enregisters 

 it, and who is in truth the discoverer, may give it the name of the finder, if he chooses. 

 We shall notice this subject in the order of names of classes and orders, of genera, of 

 species, of varieties and subvarieties, descriptions of plants, dried plants or herbariums, 

 and methods of study. 



Sect. I. Karnes of Classes and Orders. 



561. The names of the classes and orders of LinncBus and Jussieu, being exclusively 

 used at the present time, we shall pass over those of the earlier botanists. 



562. The names of the Liymcean classes and orders are, as far as practicable, expressive 

 of some common character belonging to all the plants which compose them, and consist 

 only of one word for the class, and another for the order, both compounded from the 

 Greek. There are exceptions, however, to the first rule in several of the classes 

 of the sexual system, as in Icosandna, Moncecia, Dioscia, which contain plants that 

 have not the circumstances expressed in the title. Richard (Kouv. Elem. de Pot. 

 1819) has given some new names, which he proposes to substitute for the least perfect of 

 those fixed on by Linnasus, but they are not likely to be generally received, at least in 

 this country. 



563. The names of natural orders may be taken from such genera as may serve to re- 

 call the general relations of each tribe or order. The name of the order and generic 

 name, however, are at no time to be precisely the same ; from the manifest impropriety 

 and confusion of arranging a thing under itself. Thus in the natural method of Linnaeus, 

 the order PalmiE has no genus of that name. In the method of Jussieu, die name of an 

 order is composed from the name of one of the most characteristic genera of that order, 

 as Posacece, a natural order of dicotyledonous plants, containing the well known genus 

 Posa, Sec. ; and while the name of an order is terminated by two syllables, that of a sub- 

 order is terminated by one only ; as Posacece, Posce ; Panunculacece, Panunculte. 



Sect. II. Names of Genera. 



564. Names from the Greek or Latin are exclusively admitted by modern botanists, all 

 others bping esteemed barbarous. Without this nile we should be overwhelmed,, not only 



