202 CONVOLVULACE^. 



yet it is very apt to start away green in spring. This can only 

 be obviated by lifting the plants in autumn or early winter and 

 storing them in a drier and warmer position, either out of doors 

 or under cover of glass, or cover of any kind that may be put 

 on during rain or snow, or very severe frost, and removed at 

 other times. It should be cultivated for the sake of the hand- 

 some foliage alone ; and if any indication of flowering manifests 

 itself, the centre of the stem should be pinched out at once, as 

 the development of the flower-stems, if allowed, will lead to 

 deterioration of the leaves, and not unfrequently also the loss 

 of the plant altogether in dry soils or seasons. Even if left 

 out of doors it is benefited by being annually transplanted into 

 new or fresh soil, and by being divided : this to a considerable 

 extent prevents attempts at flowering, and the more thorough 

 the division, the more effectually it does so ; but of course the 

 process will be regulated by the necessity for increase in each 

 individual case; and it should be stated, that without some 

 assistance from artificial heat, very minute divisions do not 

 make much bulk the first season. 



P. pulcherrimum {Prettiest Greek- Valerian), — A dwarf er 

 plant than the last, reaching at the most only about i foot 

 high. It makes a more sparing development of leaves, which 

 are pinnate as in the last, but with smaller and blunter leaflets. 

 The flowers also are smaller, in rather denser trusses, are bright 

 blue, and appear throughout the greater part of summer and 

 autumn. Native of North America. 



P. Richardsonii {Richardsoii s Greek- Valeriaii). — This is a 

 neat and pretty plant, forming attractive tufts of bright-green 

 pinnate leaves, consisting of ten or more small oval leaflets. 

 The flower-stems rise about 6 or 9 inches high, and terminate 

 in a i^\N rather large pale-blue flowers. They appear in suc- 

 cession throughout summer and autumn. Native of North 

 America. 



Besides these the two species Jmmile and reptans are well 

 worth growing. Both are dwarf plants, adapted for culture on 

 rockwork or the front line of mixed borders. The latter 

 flowers in spring, the other throughout summer and autumn, 

 and both are blue-flowered. 



CONVOLVULACE^. 



This is not an important order in so far as the hardy per- 

 ennial species are concerned ; they are few and not very well 



