160 PHYTOGRAPHY. 



parated by commas, which does not happen in drawing up the 

 specific characters. Colon and Semi-colon are made use of, 

 when the parts of the principal organs are to be described ; 

 for instance, in speaking of leaflets, after the principal leaf; 

 of petals, after the corolla in general ; of the partitions and 

 valves of the fruit, after the fruit itself 



249. 



Having finished the description, we proceed to give an ac- 

 count of the situation and duration of the plant, as also of 

 the use which is made of it in arts and trades. In as- 

 signing the station, correctness is chiefly to be recommended, 

 not only for facilitating the finding of plants, but also be- 

 cause the nature of a plant, and its discrimination from re- 

 lated species, depend partly upon this. The culture of 

 plants in Botanic Gardens may derive the most important ad- 

 vantages from such exact descriptions of their stations. No 

 advantage is derived from knowing that the plant grows in Af- 

 rica, A-merica, or New Holland ; but it is of the utmost impor- 

 tance to know under what degree of latitude, at what height 

 above the level of the sea, in what soil, and amidst what cir- 

 cumstances it grows. From these descriptions, which scarce- 

 ly any person has given so carefully as Humboldt, both the 

 natural historian of the vegetable world and the botanical gar- 

 dener may receive directions. 



In stating the duration of plants, we often commit mistakes, 

 especially when plants have been reared in gardens ; because 

 many tropical plants, which in their native country are per- 

 ennial, become annuals in our cHmate, from causes which we 

 cannot explain. Hence, in the writings of the great botanists, 

 many errors are found, which can only be corrected by ob- 

 serving plants in their native countries. 



