This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
The following new species have bloomed repeatedly with us this season, and we are therefore encouraged to speak of them as valuable additions to our list of hardy flowering shrubs:
Spiraea Fortunei, or Callosa. This was noticed briefly in the last volume of the Horticulturist, page 328, in an extract from the " Gardeners' Chronicle." It is a Chinese species introduced by Mr. Fortune, in habit it resembles the S. bella ; the young leaves are reddish, and the flowers are produced in large corymbs, of a rich purplish red, or a blood red, color, quite showy. It has been represented in England as "too apt to form leaves rather than flowers," but it is quite free from this defect here. Our warm July weather seems to suit it, for it blooms in the greatest profusion.
Spiraea Billardi. This is a hybrid variety, between salicifolia and Douglassi, produced by M. Billard, a nurseryman at Fontenay aux Roses in France. It has much the appearance of Douglassi in foliage. Its flowers, which are of a bright rose color, are produced in showy panicles, first at the extremities of the branches, and afterwards in the axils of the upper leaves, continuing a long time, perhaps through most of the summer and autumn, in bloom. Both this and the preceding make handsome little bushes, flowering freely, as do all the Spiraeas when quite young.
The cultivation of this genus is so exceedingly simple, that nothing could be said on that point. They are easily propagated from layers made of the young shoots during the summer months.