318 PROPAGATION OF PLANTS. : 



of tubers, care being taken to preserve at least one eye or bud on each> 

 This dividing is done in spring, the tubers having been kept in a warm, 

 dry place over winter. To multiply scarce varieties, the tubers may be 

 potted, and as the sprouts push they may be slipped off and treated as 

 cuttings, planting in sand or light soil, where they will receive a little 

 bottom heat. When roots have formed in the cuttings they should be 

 placed singly in small pots. Cuttings made of either the side or termi- 

 nal shoots, taken from large plants, strike root very readily under glass. 

 Grafting is sometimes practised, a small piece of a tuber answering for 

 a stock, the cion being inserted as shown in figure 106, and held in place 

 with a ligature of bass or fine twine. The grafted tuber is then planted 

 in a frame and given the same care and attention as usually bestowed 

 upon cuttings. 



Convolvulacece (Morning Glory or Convolvulus Family). A family 

 of half a dozen or more genera, but nearly seven hundred species. The 

 common Morning Glory (Ipomcea), and Quamadit (Cypress Vine), are 

 well-known annual climbers of this family. A few genera, such as the 

 Cuscuta (Dodder), and Calystegla (Bindweed), are weeds which have 

 become intolerable nuisances in many localities. The Sweet Potatd 

 (Ipomcea batatas), is the most valuable member of the family, although 

 there are many other species of the same genus that are extensively cul- 

 tivated for ornamental purposes. The perennial, tuberous-rooted species 

 are propagated from sprouts, which are forced out "in great abundance 

 by placing the tubers in a hot-bed, or where they will receive gentle 

 bottom heat. The sprouts, when a few inches long, are pulled off and 

 planted out separately. This is the usual mode of propagating the 

 varieties of the Sweet Potatoes, but this and other perennial species may 

 be multiplied by cuttings of the vines, taken off at almost any time dur- 

 ing the summer. 



Crassulacece (Orpine Family). A large family composed princi- 

 pally of succulent herbs. There is about a dozen genera and several 

 hundred species. The best known are Bryophyllum, Crassula, Sedum, 

 Rochca and Scmpcrvivum. The common House Leek (Sempervivum tecto- 

 runi) is a familial* and good representative of the family, and while the 

 other genera may not be as hardy or as difficult to kill out, still they 

 may be readily propagated by divisions, or cuttings of leaves and stems. 



Cructferece (Mustard Family). A large order containing many 

 kinds of useful and edible, as well as ornamental plants. There are 170 

 genera and nearly 1,300 species. Many of our common garden veg- 

 etables, such as Cabbage, Cauliflower, Cress, Horseradish, Mustard and 

 Turnip, belong to this family, but the propagation of these plants is to 

 familiar to all cultivators to be repeated here. Among the ornamental 

 genera, the following are worthy of some attention : Arcibis (Rock 

 Cress), Alyssum (Sweet Alyssum), Ibcris (Candytuft), Chieranthus (Wall- 

 flower), Ilesperis (Garden Rocket), and Matthiola (Stock or Gilliflower). 

 These, however, are all easily propagated by seeds, divisions, or from 



