Notes on Potentilla.--IV. 



By p. a. Rydberg. 

 (Plates 274 and 275.) 



The Aiireae resemble much the Frigidae except that the 

 leaves have more than three leaflets. They are all low plants, 

 generally less than 2 cm. high, except P. dissecta,\s\{\Q}is. sometimes 

 reaches a height of 3 cm. The pubescence is scant, silky, strigose 

 or hirsute, only in a variety of P. dissecta a little tomentose on the 

 lower surface of the leaves, and the plant often becomes glabrous 

 and shining in age. The style in all is very slender and filiform, 

 fastened near the apex of the achene and generally much longer 

 than the achene. Most of the species belonging to this group have 

 truly digitate leaves, but in the North American representatives 

 the outer leaflets are often inserted lower down and the leaves be- 

 come pinnate with approximate leaflets. 



