July 23, 1910 



HORTICULTURE 



101 



Notes From the Arnold Arboretum 



The genus Sorbaria has been enriched during the last 

 years by a number of very desirable Asiatic species. 

 They all flower later than the well known Soriaria sorbi- 

 folia (Spiraea sorbifoUa) and this alone would be a 

 point in their favor, but they possess besides other fea- 

 tures which make them superior to the old species. The 

 one nearest to this and closely following it in the time of 

 flowering is Sorbaria stelUpila, a Japanese species, 

 which differs in its more spreading habit and taller 

 stature. Still higher grows S. assurgens which attains 

 a height of eight to ten feet and differs in its narrower 

 and more numerous leaflets with very close set veins and 

 in its larger and somewhat looser panicles. Like the 

 preceding it is of more spreading habit and therefore 

 more graceful than the S. sorbifolia. The handsomest 

 uf all is S. Aitchisonii; it grows almost as tall as the pre- 

 ceding species and is still more graceful, chiefly on ac- 

 count of its bright green handsome foliage which con- 

 trasts beautifully with the usually red stems; the leaf- 

 lets are narrow and lustrous and very distinct from the 

 foliage of the other sj^ecies; the panicles reach fifteen 

 iuelies in length, they are rather loose and add much to 

 the gracefulness of the shrub. Unfortunately this spe- 

 cies is not quite hardy in the neighborhood of Boston, 

 though it will survive an ordinary winter without being 

 much injured. Eemarkable for its comparatively great 

 heiglit it attains is S. arborea recently introduced by 

 Wilson from western China. It reaches twenty feet in 

 height in its native country; its panicles are open and 

 loose and almost as broad as high. Another species also 

 recently introduced by Wilson grows almost as high, but 

 differs in its quite glabrous foliage purplish in a young 

 state; this species is quite new and has not yet been 

 named and described. The two last named species are 

 apparently hardy and certainly valuable additions to our 

 summer-flowering shrubs. All the species are very ef- 

 fective with their large clusters of white flowers and 

 their graceful pinnate foliage. They are easily propa- 

 gated by seeds and by hardwood cuttings and are worthy 

 the attention of the nurserjTnan and landscape gardener. 



The summer-flowering Spireas are at present almost 

 the only group of shrubs which afford a great variet)' of 

 different fonns in bloom. They are all low or medium- 

 sized shrubs well adapted to be planted as single speci- 

 mens on the la\vn or in the borders of shrubberies. One 

 of the handsomest is Spiraea Bumalda var. Anthony 

 Waterer with large flat clusters of crimson flowers ; it 

 grows only two or three feet high, while the similar S. 

 jnponica var. airosaiiguinea with deep pink flowers at- 

 tains a heiglit of about five feet. Another handsome form 

 is 1?. Margarifae with large corymbs of pink flowers pro- 

 duced in great profusion ; it grows three or four feet high 

 and a well developed specimen forms a round bush cov- 



ered all over with its large flower clusters. Spiraea revir- 

 escens with light pink flowers shows the peculiarity to 

 bloom a second time during September and October. 

 Spiraea concinna with pinkish white flower clusters is 

 also very free flowering and handsome. Another good 

 form is S. superba with liglit pink or pinkish white flow- 

 ers. While all the Spireas mentioned so far have their 

 flowers in large flat clusters. .S'. syringiflora bears its pink 

 flowers in broad pyramidal panicles ; it scarcely exceeds 

 two feet in lieight and is a very handsome free flowering 

 shrub. Similar but with white or pinkish white flowers 

 is S. nothaj it attains about three feet in height. Still 

 somewhat higher are 8. sanssouciana and S. Nobleana 

 witli pink flowers. From four to sLx feet high grow the 

 old and well known species as ;S'. Douglasii, S. Menziesii 

 and S. BilliariKi with pink flowers in elongated pani- 

 cles. With these summer-flowering Spireas the best 

 results will be obtained, if they are pruned rather severe- 

 ly in autumn or early spring, as the flowers appear at the 

 end of the young shoots and the more vigorous the shoots 

 are the larger will be the flower clusters. 



Rose Prof. C. S. Sargent 



The Cb.inese and Japanese Eosa Wichuraiaua has 

 proved an excellent parent to many of our best hardy 

 garden roses, but in no case has it proved more valuable 

 tlian in the production of the hybrid rose which forms 

 the cover illustration of this issue. In the first instance 

 E. Wichuraiaua was crossed with E. Crimson Eambler 

 and then the progeny was recrossed with E. Baroness 

 Eothschild with the result that the seedling combines 

 all the good qualities of the three roses which have been 

 used in its evolution. The flowers are single, about 

 three inches across, pale rose in color and produced in 

 the greatest profusion in pyramidal clusters all along 

 the strong branches — one cluster carrying fully sixty 

 blossoms — from the middle of May till the end of June. 

 The foliage has the desirable glossy green color so char- 

 acteristic of E. Wichuraiaua and remains in good con- 

 dition til! late in fall. 



As a garden rose this variety has a great future be- 

 fore it and it is very appropriate that such a meri- 

 torious addition to the list should receive the name of 

 the distinguished director of the Arnold Arboretum. 

 Jackson Dawson has given us a number of valuable 

 roses and it is to be hoped that this successful hybridist 

 will continue his efforts in this line and give us still 

 more rose? as good as the Prof. C. S. Sargent. 



Our Sixth Annual Convention Number 



^ Will be issued under date of August 13, 1910. It will be full of interest for those who go 

 to the Convention at Rochester, and equally so for those who stay at home. It will be widely 

 distributed and in publicity value to the advertiser will have no superior. Take a generous sized 

 space. You'll find yourself in good company. ^ ^ J- ^ ,^ ^ ^ ^ ^ 



IT PAYS ! 



IT PAYS! 



IT PAYS ! 



