170 SYSTEMATIC BOTANY. 



Ranunculaceee, we have the tribes Anemonece from Anemone, Ran- 

 unculece from Ranunculus, Hellebores from Helleborus, &c. ; and in 

 botanical works these names of tribes are commonly printed in 

 italics like those of genera and species, while the names of families 

 and all above them are printed in roman letters. 



The names applied to the larger divisions of the Vegetable Kingdom in 

 Natural Arrangements are generally made as characteristic as possible ; 

 but, as will be shown in the Section on Natural Arrangements, none of 

 the single characters of such groups are absolute, and therefore no name 

 founded on one character can be universally descriptive. Thus the 

 name Monocotyledoues is applied to a most natural group, in which are, 

 however, included one or more orders, as the Orchidacese, in which the 

 embryo has no cotyledons. And it may be said that to an advanced 

 student it is far more beneficial to regard all names as abstract signs, used 

 rather to indicate certain plants or groups of plants with which he is 

 acquainted, than as expressive of the characters of the plants to which 

 they are applied. 



These observations on the nomenclature of the Orders and higher 

 groups of plants are placed here for the sake of connexion with the 

 remainder of the subject; but they will be better appreciated after 

 acquaintance is made with the illustrations of them in succeeding 

 Sections. 



Sect. 3. DESCRIPTION OF PLANTS. 



It is the business of every botanist who distinguishes and names 

 a new species of plant to furnish an exact statement of the charac- 

 ters by which it may be recognized by others. 



The most complete fulfilment of this requisition is supplied in 

 what is termed a description of a plant, in which is given a detailed 

 account of the external form, the arrangement and relations of 

 all its organs, according to a fixed plan and in a fixed language, 

 furnished by the terminology made use of in Morphology. 



In order to impress upon the mind of the student the principal points 

 to be looked to in describing a plant, and thus to ensure completeness and 

 accuracy of observation, we subjoin a list of the more salient characteristics 

 which it is desirable to notice in writing a full description of a plant. 

 Some of these are of much greater importance than others, inasmuch as they 

 afford the means of grouping plants into genera and orders, not only phy- 

 siologically but morphologically, &c., and furnish what are called dia- 

 gnostic characters. From their great importance, much stress is deservedly 

 laid on them ; hence, after enumerating the principal "characters " neces- 

 sary to be ascertained in drawing up a full description, we shall insert 

 illustrations of the "schedules'' introduced with so much success for 

 teaching-purposes by the late Professor Henslow, and in which attention 

 is drawn solely to those points of special importance. 



It must also be borne in mind that the terms used are such as are in 

 general use, and are to be taken in their conventional sense, and not as 



