THE NURSERY-LIST 437 



handled in frames give excellent results. V. tomentosum ( V. plicatum 

 of nurseries) is propagated by cuttings. Ripe cuttings are some- 

 times used for the soft-wooded species. The snowball or guelder-rose 

 (V. Opulus) is rapidly increased by layers, and it propagates well by 

 mature cuttings in summer in a frame or propagating-house (Fig. 

 124) . It is also a good stock for closely related species. V. Lantana, 

 V. dentatum and V. Opulus are good stocks on which varieties 

 difficult to handle can be worked by the veneer-graft in winter. 



Vicia (Vetch). Leguminosce. 



Propagated by seeds sown where plants are to grow. V. Faba is 

 the broad or Windsor bean, which is hardy and a cool-season plant, 

 and the large seeds should be planted early in the season. The 

 forage and cover-crop vetches are sown at the rate of 40 to 100 

 pounds and more to the acre. As a cover-crop in orchards, 30 to 

 50 pounds are usually advised. 



Victoria (Royal Water-Lily). Nymphceacece. 



Grown from seeds. There are two species, one (V. regia) requiring 

 a water temperature of 85 to 90 for germination, and the other 

 (V. Cruziana or Trickeri) a temperature of 65 to 70. The seed is 

 usually sown in February or March in pots or seed-pans that are 

 set in shallow water. Young seedlings are transferred to small pots, 

 and kept growing continuously until large enough and weather is 

 warm enough for transfer to the tanks for blooming. The victorias 

 are annuals and do not form tubers. 



Vigna. Leguminosoe. 



Increased by seeds ; the cow-pea or black-pea (Vigna sinensis) by 

 seeds when danger of frost is past. 



Vinca (Periwinkle). Apocynaceoe. 



Increased chiefly by division and by cuttings, also by seeds. V. 

 rosea may be propagated annually by seeds. 



Viola (Violet. Heartsease. Pansy). Violacece. 



The wild violets may be grown easily from seeds sown in autumn 

 in protected boxes, germination taking place in the spring, the 

 boxes having been exposed to freezing. Dividing the plants is a 

 common method of increase. Some species propagate themselves 

 by runners. 



The florist's violet is readily propagated by offsets or separable 

 parts that form in late winter; these are removed and treated as 



