138 DESCRIPTIVE BOTANY. PART I. 



I. Class .... Dicotyledones. 



* Sub-class - - Calyci flora 1 . 

 II. Order - Lcguminosa 1 . 



* Sub-order - - Papilionaceae. 

 ** Tribe - - Lotea. 



*** Sub-tribe - - Genisteae. 



III. Genus - - Antliyllis. 



* Sub-genus (or Section) - - Vulneraria. 

 IV. Species - Vulneraria. 



* Variety - - Dillenii. 



** Race ... - Florilms coccineis. 



*** Variation - - Foliisliirsutissiniis. 



(132.) Value of Characters. In determining the 

 particular group to which a plant belongs, it is neces- 

 sary to compare its " characters" with those of other 

 species. By the term " characters/' we mean the pecu- 

 liar appearances presented by different organs. Thus, 

 a leaf may be round, lanceolate, &c. ; the petals may 

 be united, abortive, &c. ; and these adjectives denote the 

 peculiar characters of these organs. It will readily be 

 understood, that some characters must be of much 

 greater importance than others, in determining the 

 affinities of different species. Thus, the first degree 

 of affinity in phsenogamous plants, is almost always to 

 be ascertained by a single character, residing in the 

 embryo ; and we may determine at once, to which of 

 the two primary groups it belongs, by attending to this 

 circumstance alone. But even here, this primary cha- 

 racter may be so far disguised or modified, as inevit- 

 ably, in some instances, to lead us into error, if it 

 were not possible for us to check our observations by 

 other considerations, of secondary importance in most 

 cases, but which, in the present instance, are quite 

 sufficient to correct our judgment, and to satisfy us 

 of the real affinities of the plant in question. Thus, 

 in the genus Cuscuta, the character of the flower, 

 the structure of the stem, and other circumstances, 

 clearly indicate that it belongs to the class " Dicotyle- 

 dones" although the embryo has no cotyledons, and the 

 stem is leafless. The inference to be drawn from these 



