SYRINGA CHINENSIS (_syns. S. dubia_ and _S. rothomagensis_).--Rouen, or Chinese Lilac. A plant of small growth, with narrow leaves, and reddish-violet flowers. It is said to have been raised by M. Varin, of the Botanic Garden, Rouen, as a hybrid between S. vulgaris and S. persica, 1795. S. EMODI.--Himalayas, 1840. This is a desirable species, that forms a stout bush or small tree, with oblong, reticulately-veined leaves, and erect, dense panicles of white flowers, that are sometimes lilac tinged. The flowers are strongly scented, and borne in great profusion late in the season. There is a variegated form, S. Emodi variegata, and another named S. Emodi villosa, both good varieties. S. JAPONICA (_syns S. amurensis_ and _Ligustrina amurensis_).--Japan. This is of recent introduction, and is a decided acquisition, producing in summer large and dense clusters of creamy-white flowers. It is a very desirable species, and though coming from Japan seems to be perfectly hardy. S. JOSIKAEA, Josika's Lilac, is of Hungarian origin (1835), and is so totally different from the others as to be well worthy of special attention. It rarely exceeds 6 feet in height, with dark-green, wrinkled leaves, and erect spikes of pale mauve flowers. S. PERSICA (Persian Lilac).--Persia, 1640. This is a distinct small-growing species, with slender, straight branches, and lilac or white flowers produced in small clusters. The form bearing white flowers is named S. persica alba; and there is one with neatly divided foliage called S. persica laciniata. S. VULGARIS.--Common Lilac, or Pipe Tree. Persia and Hungary, 1597. This is one of the commonest and most highly praised of English garden shrubs, and one that has given rise, either by natural variation or by crossing with other species, to a great number of superior forms. The following include the best and most ornamental of the numerous varieties:--alba, pure white flowers; alba-grandiflora, very large clusters of white flowers; alba-magna, and alba virginalis, both good white-flowering forms; Dr. Lindley, large clusters of reddish-lilac flowers; Charles X., purplish-lilac flowers, but white when forced; Souvenir De Ludwig Spath, with massive clusters of richly coloured flowers; Glorie de Moulins, Marie Legrange, Noisetteana, Duchesse de Nemours, and Vallettiana, all beautiful flowering forms that are well worthy of cultivation, and that are of the simplest growth. The double-flowered varieties, for which we are much indebted to M. Victor Lemoine, of Nancy, are fast gaining favour with cultivators in this country, and rightly, too, for they include several very handsome, full flowered forms. The following are best known:--