POPULAR GARDEN PLANTS. 



493 



borders. They are propagated by division after 

 the plants have done flowering, and also from 

 cuttings made of the side-shoots formed at the 

 end of the summer. These should be set in 

 a cold frame, or under a hand-glass in a shady 

 border. When rooted they can be planted out 

 either in the autumn or early spring. 



The double -flowered varieties do not seed 

 easily, and the seedlings are generally inferior. 

 The single varieties are better in this respect. 



Fig. 600.— Pyrethrums. 



The seed should be sown in pans in early 

 spring and placed in a cold frame or on a shelf 

 in a cool greenhouse, covering them with a pane 

 of glass, and shading until they germinate. 



Selection of Sorts. 



Double-flowered. — Alfred, Aphrodite, Duchess of Teck, 

 Empress Queen, Ernest, Evelyn, Eigaro, King Oscar, 

 Lady Kildare, Lenoard Kelway, Lord Posebery, Milton, 

 Pericles, Primrose, Princess Beatrice. 



Single-flowered. — Alice, Apollyon, Dorothy Kelway, 

 F. M. Peacock, James Kelway, J. G. Clarke, Lord 

 Roberts, Macbeth, Mary Anderson, Millicent, Pascal, 

 Princess Irene, Princess Marie, Princess of Wales, Ruth. 



Rhododendron (Hardy). — Undoubtedly 

 the finest and best of hardy evergreens, no 

 other genus combining so much variety of 

 colour, so much beauty of both flower and 

 foliage, with vigour and hardiness. 



The garden Rhododendrons, as distinct from 

 the species from which they are derived, are 

 quite a modern acquisition. The most import- 

 ant of the parent species — R. catavjbien.se, R. ar- 

 boreum, and R. caucasicum — have been introduced 

 within the last hundred years. R. ponticum, 

 which has also played a part in the production 

 of the garden race, was introduced in 1763, but 

 does not appear to have been used for hybri- 

 dizing until long afterwards. Although other 

 crosses, accidental or otherwise, had been pre- 

 viously obtained, the first results which may be 

 said to have begun the evolution of the garden" 

 Rhododendrons, as we know them to-day, were 

 obtained between 1826 and 1835. About this 

 period the Himalayan, R. arboreum, introduced 

 in 1820, flowered for the first time under culti- 

 vation. It is easy to imagine the effect of 

 its glorious crimson trusses on people who 

 had only seen before the comparatively in- 

 effectual and indeterminate hues of the Euro- 

 pean and American species then in gardens. 

 At any rate, the desire was generally felt to 

 get some of its vivid colour into the open air 

 (for it is, itself, only hardy in very few parts 

 of the United Kingdom), and it was used 

 by several hybridists between the dates 

 mentioned. Thus were obtained altaclerense 

 (arboreum x species unrecorded), Nobleanum 

 {arboreum x caucasicum), Russellianum (arboreum 

 x catawbiense), Smithii (arboreum x ponticum). 

 These first hybrids, raised from R. arboreum, 

 naturally retained some of its tenderness, as 

 well as its propensity to break into flower 

 early in the year. But a beginning had been 

 made, and by repeated crossing and selection 

 a hardy, later -flowering race was gradually 

 evolved, which still retained much of the vivid 

 colour of the Himalayan species. In fact, all 

 that is red or crimson in the flowers of the 

 garden race of Rhododendrons has its origin 

 in the "blood" of R. arboreum. In the varieties 

 that are most free from any purple tinge, such 

 as Michael Waterer and Doncaster, even the 

 foliage still bears a strong impress of that 

 species. During the years that followed the 

 first crosses with R. arboreum, several hybridists 

 took in hand their improvement ; but the most 

 noteworthy, both as regards the length of 

 time over which their work has extended and 

 the results obtained, were the Waterers of 

 Knap Hill and Bagshot. Their labours may, 

 indeed, be said to have largely given to the 

 great bulk of the garden Rhododendrons of 

 the present day their chief distinctive features. 



Whilst the great majority of the varieties 



