PERIWINKLES 371 



ever, as these trees are in such places, nothing approaching the full value 

 is got out of them by this neglect. Their numerous suckers are allowed 

 to gi-ow unchecked, and consequently the elegant tree becomes a shapeless 

 bush that flowers sparingly. The chief attention required is the removal 

 of these suckers and the digging in of fresh soil from time to time. The 

 waste of energy stopped, a main trunk is formed, and the bush becomes 

 a tree upon which, in spring-time, blossoms are more conspicuous than 

 leaves. Propagation is easily effected by means of cuttings inserted in a 

 shady border, or more quickly by utilising the suckers for the purpose. 

 Varieties are also reproduced by budding, crown-grafting, and cleft- 

 grafting. Budding may be performed either in April or July ; grafting 

 should be done in March, and the stock used should have been raised 

 from seed. For forcing, strong plants are grown in pots with loamy soil, 

 outdoors, and those with plenty of flower-buds are taken in, in succession, 

 during the winter, and submitted to a moist temperature of 55°, which 

 may be gradually increased to 00°. Flower-buds are distinguished from 

 wood-buds by their roundness and larger size. Plants cannot be forced 

 two seasons in succession ; after flowering they should be cut back and 

 turned into the border. 



Description of Plate 178. Syriiiga vulgaris, the Common Lilac: flowers 



Piatesi78andi79.and leaves. Fig. 1 is a detached flower, enlarged; 2, a 

 section of the same. 



Plate 179. A. S. j^ersica, the Persian Lilac; Figs. 1 and 2, enlarged 

 flower and section respectively. B. S. chinensis, or Rouen Lilac. 



PEEIWINKLES 



Natural Order Apocynace^. Genus Viiica 



ViNCA (the Roman name, from vincio, to bind or connect: in allusion to 

 use of its pliant stems). A genus of about ten species of perennial herbs 

 or under-shrubs, with opposite- evergreen leaves, and white, blue, pui-ple, 

 or rosy flowers. The calyx has five pointed lobes. The corolla is salver- 

 shaped with five oblique lobes, the tube hairy within, the throat angled 

 and thickened. The five stamens have very short filaments, and the 

 anthers have a bearded membrane at the tip. The ovary consists of 

 two cai-pels, and the long style supports a cup in which is the stigma. 

 The fruit consists of a couple of slender rounded follicles containing many 

 seeds. The species are natives of Europe, Asia, and Africa ; two being 

 found in Britain, but both probably introduced. 



