ELEMENTARY BOTANY. XXV 



together into groups of a higher degree called Families or Natural Orders, to 

 each of which a common name has been given. This name is in Latin an adjective 

 plural, usually taken from the name of some one typical genus, generally the best 

 known, the first discovered, or the most marked (e. g. Ranunculacece from Ranunculus). 

 -Ihis is however for the purpose of study and comparison. To speak of a species, to 

 refer to it and identify it, all that is necessary is to give the generic and specific names. 



182. Natural Orders themselves (of which we reckon near 200) are often in the 

 same manner collected into Classes ; and where Orders contain a large number of 

 genera, or genera a large number of species, they require further classification. The 

 genera of an Order are then collected into minor groups called Tribes, the species of 

 ■ genus into Sections, and in a few eases this intermediate classification is carried still 

 , .her. •^ ne names of these several groups the most generally adopted are as follows, 

 beginning with the most comprehensive or highest : — 



Classes. Genera. 



Subclasses or Alliances. Subgenera. 



Natural Orders or Families. Sections. 



Suborders. Subsections. 



Tribes. Species. 



Subtribes. Varieties. 



Divisions. 

 Subdivisions. 



183. The characters (3) by which a species is distinguished from all other species of 

 , e . 8fune genus are collectively called the specific character of the plant ; those by 



oth n! geUus is di8 tmguished from other genera of the Order, or its Order from 

 ner Orders, are respectively called the generic or ordinal character, as the case 

 ay be. The habit of a plant, of a species, a genus, etc., consists of such general 



Sy.j as 8trike the e 3' e at first fight, such as size, colour, ramification, arrange- 

 ent of the leaves, inflorescence, etc., and are chiefly derived from the organs of 



Te getation. 



in f . Classe8 » 0r ders, Genera, and their several subdivisons, are called natural when, 

 ace 01 ?" 15 them ' a11 resem hlances and differences are taken into account, valuing them 

 diff Mg t0 their evide nt or presumed importance ; artificial, when resemblances and 

 rIo«!r nc ^ e8 , ln 8ome one or very few particulars only are taken into account indepen- 

 aently of all others. 



Order' Ptl n um her of species included in a genus, or the number of genera in an 



diffe 



SDecipa r»«» «a iu uuiisuuuwj me enure kouub . *» """""i 



is the ™ I l a ? r . re8emble each other so much as t0 be a11 in _ cluded "I2 ne % e . nuB ; and there 



differ lV ery variabl e- Sometimes two or three or even a single species may be so 

 srJfl n l 0m a11 oth er8 as to constitute the entire genus : in others, several hundred 



fortur. ^T dl8cre pancy in the number of genera to a Family. There is moreover, ran 

 Planta^ff ' m a num ber of instances, great difference of opinion as to whether certain 

 G*to * e ," ng from each other m certain particulars are varieties of one species or De- 

 stitute nct s Pecies ; and again, whether two or more groups of species should con- 

 «end- aS - many 8ections of one genus, or distinct genera, or tribes of one Order, or 

 real ei"t Natural Orders. In the former case, as a species is supposed to have a 

 solute Ir* m nature . the question is susceptible of argument, and sometimes of ab- 

 tmrv C- , But the P ,ace a g TOU P should occupy in the scale of degree isveryarbi- 

 rect niH " g i n a mere question of convenience. The more subdivisions upon cor- 

 alwavs tT lP 8 are multiplied, the more they facilitate the study of plants, provided 

 hensL jj" 11 resting-points for constant use, the Order and the Genus, are compre- 

 >nto a d- f • dl8tinct - But if everv group into which a genus can be divided be erected 

 'ssnou!! t,nct , genus, with a substantive name to be remembered whenever a species 

 •KWncnrf* ' aU the advantages derived from the beautiful simplicity of the Linnmui 

 "nature are gone. 



