170 AN INTRODUCTION 



have been given to these distinctions, are to be ne- 

 glected as impertinent in this science, though for 

 the purposes of gardening they have their use. 



The VIRTUES and USES of plants furnish no spe- 

 cific difference ; and the distinctions therefore of phy- 

 sical writers are not always to be depended on. 



The DURATION of plants is no sure mark of dis- 

 tinct species, being often owing rather to the place 

 than to the nature of the plant. In warm regions, 

 plants that are annual with us will become perennial 

 01* arborescent; as is found in Tropaeolum, Beta, 

 Majorana, Malva arborea, c. And on the con- 

 trary. cold regions will occasion perennial plants 

 to become annual ; as is observed in Ricinus, Mi- 

 rabilis, &c.* 



MULTITUDE or quantity is an accidental circum- 

 stance in plants, and cannot conclude any thing, 

 whether the increase be of the plant itself, or of its 

 roots, steins, leaves, or fructification. 



PUBESCENCE is an uncertain mark; as by culture 

 and change of soil plants are subject to lose as well 

 their spines as their hair or down. 



LEAVES, though they for the most part furnish 

 most elegant specific differences, as has been observ- 

 ed in the last chapter, are yet subject to luxuria- 

 tion in the same species, which must be carefully 

 distinguished. This may respect their opposition 

 and composition, and also their being crisp (curled) 

 or bullate (bladdery.) 



In respect to opposition, opposite leaves will some- 

 times become tern, quatern, or quine, growing by 

 threes, fours, or fives ; and then the stem also from 

 quadrangular, square, will become polygonous, of 

 many sides f. 



1 * Ricinus aad Mirabilis are naturally perennial plants, and 

 are only killed by frost in cold countries. 



t Lysimachia lutea major foliis ternis (Tourn.) 

 Lysimachia lutea major foliis quaternis (Tourn.) 



