176 SYSTEMATIC BOTANY. 



Generic Character. The generic character is perhaps the most 

 important element in Systematic Botany. It should contain a short 

 description of the peculiarities of the group, so as at once to cha- 

 racterize this as it exists in itself, and to furnish the means by 

 which it may be distinguished from all other genera belonging to 

 the same division of the Vegetable Kingdom. The following ex- 

 ample of the character of the genus Campanula, Linn., as given in 

 Endlicher's ' Grenera Plantarum,' will illustrate this : 



"Campanula, Linn. Calyx with an ovoid or suhspherical tube adherent 

 to the ovary, the limb superior, five-toothed ; the teeth either flat at their 

 margins or decurrent into lobes overlying the sinuses. Corolla inserted 

 at the summit of the tube of the calyx, more or less campanulate, five- 

 lobed or five-toothed at the apex. Stamens five, inserted with the corolla ; 

 filaments broadly membranaceous at the base, and, with the anthers, free. 

 Ovary inferior, three- or five-celled ; cells superposed to the lobes of the 

 calyx. Ovules numerous, on pla,centas projecting from the central angles 

 of the cell, anatropous. Style covered with quickly deciduous hairs ; 

 stigmas 3-5, filiform. Capsule ovate or turbinate, 3-5-celled ; cells burst- 

 ing near the top or bottom by a parietal valve turning upward. Seeds 

 numerous, mostly ovate, flattened, more rarely ovoid and very small. 

 Embryo orthotropous, in the axis of fleshy albumen ; cotyledons very short ; 

 radicle next the hilurn, centripetal. 



" Perennial or annual herbs, sometimes low and tufted, sometimes erect, 

 tall, many-flowered, diffused through all the temperate and cool regions 

 of the northern hemisphere, forming a great ornament to meadows and 

 groves ; radical leaves very often larger and more obtuse, with longer 

 stalks; stem-leaves alternate, varying ; flowers mostly stalked, racemose, 

 rarely spiked or in clusters, very often rather large, blue, or sometimes 

 white in the same species." 



The first paragraph here contains the essential character of the 

 genus ; the second paragraph is a description of the general cha- 

 racters of the species belonging to it, which is usually appended to 

 such complete generic characters. 



It will be observed that this generic character not only enables us to 

 distinguish plants belonging to this group, but describes the genus so fully 

 that we become acquainted with all its important peculiarities, while, 

 being drawn up irrespectively of any Order, alliance, or class, it is equally 

 available as material for any 'Natural or Artificial classification of Flower- 

 ing plants founded on the floral organs, since it contains the information 

 requisite for ascertaining its relations. 



Diagnosis. The diagnosis of a genus is -more limited in its 

 nature and purpose. It is used, when genera are described under 

 fixed systematic heads simply for distinctive purposes; and it is 

 therefore confined to denoting what is absolutely necessary for this 

 purpose. Thus, in Babington's ' Manual of British Botany,' the genus 

 Campanula occurs under the head of the Order Campanulacea?, the 

 character of which includes much of what is given in the generic 



