THE NURSERY-LIST 263 



always more or less injured. It is always best to cut away the 

 roots, let the w r ounds dry and heal for a time, and then treat the 

 plants as cuttings. Many of the opuntias are naturally adapted 

 to propagate themselves vegetatively. The stems are readily 

 detached at the joints. These stems fall to the ground and in a 

 short time develop roots and begin to grow as independent plants. 

 In many of the opuntias the fruits are sterile but proliferous. 

 These fruits may be removed and treated as cuttings and will 

 readily produce new plants. Many of the smaller kinds, such as 

 echinocactus, echinocereus, and mamillaria, produce branches 

 that are readily detachable and easily rooted as cuttings. Some 

 species of mamillaria have side shoots which are so lightly attached 

 that they break off by a slight touch. 



Grafting is easily accomplished in cacti. The possibilities of 

 uniting both species and genera seem to be unlimited. For a long 

 time it has been a practice to graft epiphyllum on pereskia or some 

 upright stiff -stemmed cereus in order to produce a more decorative 

 bush plant. The rat-tail cactus (Aporocactus, or Cereus, flagelli- 

 formis) is frequently treated in the same way. It not infrequently 

 happens that a plant becomes decayed at its base, and when all 

 evidence of decay or disease has been removed there will be so little 

 healthy tissue left that it is next to impossible to get it to grow as a 

 cutting. Such a piece may be grafted on a healthy stock and the 

 plant be preserved, if the growing tip is intact. A cleft-graft or 

 saddle-graft is more desirable when either of these can be employed, 

 since they require less work in preparation and give a large surface 

 for the union of the tissues. The mucilaginous sap that exudes 

 from the cut surface allows the stock and cion to slip apart very 

 easily, and the parts become disarranged unless proper precaution 

 is used to prevent it. For this purpose the needle-like spines of 

 pereskia or opuntia may be used. The two parts are pressed 

 firmly together into the desired position, and then a spine is thrust 

 through the united portions, securely pinning them in that position. 

 No wax is required, but it is best to wrap the graft closely with 

 raffia to exclude the air. The grafted plants are then placed in 

 a warm moderately moist place until the tissues have become 

 thoroughly knitted together. They should not be placed where 

 subject to drying, for under such conditions the cut surface will 

 be the first to dry, and consequently a perfect union will be 

 prevented. 



With small globose or thick plants, such as mamillaria, echino- 



