56 RULES FOR 



other plants, even of the same Genus, in the reader, 

 as well as any allusions to the rarity or frequency of 

 a plant, are manifestly faulty. 



The Root (7) often affords solid specific distinc- 

 tions, but is not infallible; nor can it always, in cul- 

 tivated plants, or in dried specimens, be examined, 

 or preserved. 



Stems (12) frequently afford clear and certain di- 

 stinctions, in their forms, postures, angles, wings, or 

 other particulars. 



Leaves (30) abound in the most elegant and un- 

 exceptionable characters for specific discrimination, 

 in their situation, form, division, surface, margin, 

 veins, and even pubescence. But scarcely any one 

 mark concerning them is absolute, throughout all 

 plants whatever, and experience only can teach, in 

 every case, what is most to be relied on. 



Appendages (47) are usually very serviceable in 

 specific characters, especially the Stipulas, as to their 

 presence or absence, situation, form, or even duration. 



Inflorescence (48) is declared by Linnseus to yield 

 the best of all specific differences. Phil. Bot. sect. 

 279. The importance of the distinctions to be de- 

 rived from hence is so great, that some botanists, 

 especially of the French school, do not scruple to 

 found some of their Generic Characters upon it. 

 Even Linnseus is justly charged with having had re- 

 course to the inflorescence, in arranging the Genera 

 of the Umbelliferous tribe (48:7), though the prin- 

 ciple is disguised under the idea of an Aggregate 



