LIST OF FLOWERS 



the Rock Garden respectively. The former, with its delicate blue 

 blo^oms, makes a charming training plant for the greenhouse, while 

 the latter is perfectly hardy and forms dense tufts of wiry stems, some 

 6 inches high, bearing trusses of deep blue flowers early in September, 

 which last untU the frost cuts them off. It is easily propagated by 

 division in spring. 



POLEMONIUM. A hardy perennial useful in some of its varie- 

 ties for the Rock Garden. P. humile is one of the best, but though 

 hardy on a well-drained light soil it will not endure during the winter 

 in a damp situation. It is a pretty plant with pale blue flowers set 

 on stems a few inches high. A larger kind, more suited for the 

 border, is that called Richardsonii, with clusters of bell-like flowers 

 of deep blue or of pure white. Both the white and the blue kinds are 

 fragrant and useful for cutting. P- cceruleum (Jacob's Ladder) is 

 a well-known variety of which there are several kinds — ^with blue 

 flowers, with white flowers, or with variegated foliage. 



POLIANTHES (Tuberose). The Tuberose is usually grown as 

 a greenhouse plant, but in warm districts and in a sheltered border 

 it will flower freely in the open. Its delightful fragrance and its pure 

 white flowers render it a valuable plant, and in the greenhouse it is 

 easily flowered by planting the bulbs in pots fiUed with a compost 

 of loam and leaf mould and plunging the pots in a bottom heat of 

 60° to 70°. 



POLYANTHUS. Although this is usually considered to be a 

 variety of Primula elatior (the Oxlip Primrose), it seems more con- 

 venient to place it under the heading of its well-known name of 

 Polyanthus. For rich and varied colouring the Polyanthus excels, 

 perhaps, any of our spring flowers, and though it may not yield 

 itself so well as others for producing masses of colour, it is most 

 effective when set in small clumps, so that the beauty of each plant 

 may be discerned. Its cultivation is perfectly simple, for it will 

 thrive in any garden soil, though it prefers one which is rich and 

 moist, and flourishes best in a sheltered and somewhat shady situa- 

 tion. It can easily be raised from seed sown in the open during the 

 summer months and may be increased by division in autumn or early 

 spring. Its varieties are almost innumerable and a selection may be 

 made without difficulty from any good seed catalogue. 



POLYGALA. A family of dwarf creep hg shrubs, some of which 

 are excellent for the Rock Garden. P. Chamcebuxus purpurea is a 

 beautiful example, with bright evergreen leaves and purplish stems, 

 Q 241 



