BILLBERRY BLADDER-NUT. 187 



greatly facilitate new root growth ; failing this, they will 

 root freely in the temperature of a stove, if placed in a 

 shaded position for two or three weeks, after which they 

 will bear increased light and sunshine during the latter 

 part of the day. 



Billberry. See Vaccinium. 



Biota. See Thuya. 



Birch. See Betula. 



Birthwort. See Aristolochia. 



Bitter Sweet. See Celastrus and Solanum. 



Blackberry (Rubus villosus and vars.). Rosacecr. 



New varieties are obtained from seeds, which may be 

 sown as soon as they are cleaned from the ripe fruit, or 

 which may be stratified until the next spring. If the soil 

 is in prime condition, fall sowing is preferable. 



Varieties are multiplied by suckers and by root cuttings. 

 The suckers spring up freely about the old plants, espe- 

 cially if the roots are broken by the cultivator ; but they 

 have few fibrous roots, and are inferior. The best plants 

 are obtained from root cuttings (Fig. 62). Roots from 

 one-fourth to three-eighths inch in diameter are selected 

 for this purpose. The roots are dug in the fall, cut into 

 pieces an inch or two long, and stored until early spring. 

 They may be buried in boxes of sand after the manner of 

 stratified seeds, or stored in a cool cellar ; callusing pro- 

 ceeds most rapidly in a cellar. The pieces are planted 

 horizontally an inch or two deep, in loose, rich soil. It is 

 best to put them in a frame and give them slight bottom 

 heat, although they will grow if planted in the open in 

 April or May, but the plants will make much less growth 

 the first season. Some varieties do not strike quickly 

 without bottom heat. When the variety is scarce, shorter 

 and slenderer pieces of root may be used, but these de- 

 mand bottom heat. The heat in the frames is usually sup- 

 plied by manure, or the heat of the sun under the glass 

 may be sufficient. In these frames the cuttings may be 

 started in the north late in March, or some six or eight 

 weeks before the plants can be set out-doors without pro- 

 tection. When the weather has become somewhat set- 

 tled, the plants may be planted out, and by fall they will 

 be 2 to 3 feet high. See Dewberry. 



Bladder-nut. See Staphylea. 



