326 



ICOSANDRIA. 



Rubus, t. 826, 827, 71(5; Fragaria, t. 1524; 

 Potentilla, t. 88, 89, 862; Tormentilla, t. 863, 

 864; Geum, t. 106 ; Dri/as, t. 451 ; and Comarum, 

 t. 1 72 : all elegant plants, agreeing in the astringent 

 qualities of their roots, bark and foliage, and in their 

 generally eatable, always innocent, fruit. The vege- 

 table kingdom does not afford a more satisfactory 

 example of a natural order, composed of natural 

 genera, than this ; and Linnaeus has well illustrated 

 it in the Flora Lapponica. His genus Tormentilla, 

 differing from Potentilla in number of petals and 

 segments of the calyx, though retained by Jussieu, 

 may perhaps be scarcely distinct ; yet there is a 

 difference in their habit, which has induced me to 

 leave it for further consideration. Haller united 

 them both with Frag aria and Comarum, which 

 the character and habit of the latter totally forbid, 

 and Gartner has well suggested a mark from the 

 smoothness of the seeds in Fragaria, (as well as 

 Comarum,') to strengthen that of its pulpy recep- 

 tacle. Whatever difficulties may attend these genera, 

 how admirably does the fruit serve us in Rosa, 

 Rubus, Dry as and Geum, to discriminate those 

 whose leaves, flowers, and habit all stamp them as 

 distinct ! A student cannot do better than to study 

 this order and these genera, as an introduction to 

 the knowledge of more obscure ones; and the beau- 

 tiful plants which compose it, mostly familiar to 

 every body, are easily obtained. 



