GENERA. 8 1 



Observation, 1. This is a rule of the first importance in scientif- 

 ic botany, and should be kept in view by the student from the 

 very commencement of his studying genera. To the discovery and 

 observance of this rule, botany owes its very existence as a science. 



Linnzeus first insisted on generic characters being exclusively 

 taken from the seven parts of fructification, and he demonstrated 

 these to be sufficient, for all the plants that can be discovered. 



2. The most important characters are afforded by those parts of 



plants which are most essentially concerned in the reproduction of 



the species, as the flower and fruit ; it follows then, that plants 



which agree in these, whether they agree in other points, or not, 



are allied ; and those which do not, are fundamentally different. 



2. Generic characters are drawn from the number, 

 figure, situation, proportion, and connexion of eacli par- 

 ticular part of the fructification. 



Observation. 1. Thus all the different species of calyx, corolla, 

 nectary, pericarp, &c. considered with respect to the five attributes 

 just mentioned, furnish the observer with so many simple charac- 

 ters These simple characters Linnaeus denominates the letters or 

 alphabet of botany. By studing, comparing, and, as it were, spell- 

 ing these letters, the student comes at last to read and understand 

 the generic characters, which the Creator has originally imprinted 

 upon vegetables. JVtilne. 



2. Some characters are more uniform and constant than others ; 

 the parts of the flower and fruit are more constant than the other 

 parts of a plant ; and again, the situation, connexion, and pro- 

 portion of these parts, more constant than the number and 

 figure. 



Colour is in general so variable, that it is not depended on as a 

 character, either of genera or species. 



3. In some few genera, alt the parts of the flower 

 and 'fruit are constant and uniform, as the Lily, Rose* 

 Violet, Iris, &c. 



4. In others, a part only of the frucitiflcation is uni- 

 form and constant. 



5. The part that is uniform and constant in all the 

 species of the genus, is various in various genera. In 

 the genus Anemone, it is the seeds, while the petals vary 

 from 5 to 9. In the genus Acer, Maple, it is the pecu- 

 liar seed-vessel, furnished with a dilated wing, while 



the other parts are inconstant. In Hydrophyllum, it is 

 the closed chinks, which are situated within the co- 

 rolla. 



