POLEMONIUM POTENTILLA . 147 



POLEMONIUM. 



Jacob's Ladder. 



Polemonium cceruleum. Blue-flowered. This is one of the 

 old standard border flowers, and is known by the common name 

 of Jacob's Ladder, from its beautiful pinnately-cleft leaves, 

 (leaflets arranged on each side of a common petiole or leaf- 

 stem ;) its lively blue flowers, nodding, on the ends of the 

 branches. There is another variety with white flowers. Each 

 variety is worthy of a place in the flower department, being per- 

 fectly hardy and of the most easy cultivation ; flowers in June ; 

 two feet high. 



POTENTILLA. 



Potentilla, in allusion to its supposed potential virtue in 

 medicine. 



This is a numerous genus, consisting of strawberry-like look- 

 ing plants, with mostly yellow flowers. 



Potentilla atrosanguinea. Dark blood-colored Potentilla. 

 This is one of the finest species, with beautiful foliage, and 

 blood-colored flowers, from Nepal, one and a half foot high ; 

 in flower from May to September. Propagated from divisions 

 of the root, and from seed. 



Pontentilla formosa. Synon. Napalensis. This is an- 

 other beautiful species from Nepal, with fine rose-colored flow- 

 ers, which are produced the greater part of the season. 



Pontentilla splendens has yellow flowers, of not much beauty, 

 but the leaves are elegant, being silvered over with a silky 

 down, and interruptedly pinnate. Flowers dichotomous, in 

 corymbs ; from Nepal. 



Pojitentilla grandiftora has fine large yellow flowers a 

 native of Siberia. 



Pontentilla russelliana is a splendid hybrid with scarlet 

 flowers. 



