I7 6 THE NURSERY-BOOK. 



ial variety is required, the pseudo-bulbs that are more than 

 one year old should be cut into lengths, and fastened on or- 

 chid rafts, with a layer of sphagnum beneath them. Sus- 

 pend them in a hot, moist house, if possible, over a water- 

 tank. The advantage of this method is that the young plants 

 do not need shifting after they commence rooting on their 

 own account. The section to which D. aggregatum, D. Jen- 

 kinsii, D. densiflorum and D. thyrsiflorum belong, are best 

 propagated by division. (See under Orchids.) 



Dentaria (Tooth wort). Crudferce. 

 Propagated by seeds or divisions. 



Deodar. See Cedrus. 



Desfontainea. Loganiacece. 



Cuttings, placed in a sandy loam, in a gentle heat. 



Desmodium. Leguminosce. 



Increased by seeds, or by cuttings placed under a frame, 

 in heat. 



Deutzia. Saxifrages. 



Commercially, the species are mostly propagated by green 

 hardened cuttings in summer, under a frame. Hard-wooded 

 cuttings may be taken in autumn, and be treated in about 

 the same manner as currant cuttings (see page 58). The 

 deutzias are also propagated by divisions and layers. Some 

 of the dwarf sorts are sometimes forced, to make cuttings 

 for winter use. 



Dewberry (Rubus Canadensis and vars., and Rubus trivialis. 



Rosacece. 



Seeds are handled in the same manner as blackberry seeds. 

 Increased by layers and, like the blackberry, by root cut- 

 tings. Layers are made by simply covering the decumbent 

 canes at the joints. This is the usual method of multiplica- 

 tion. The tips, too, root freely, as in the black-cap rasp- 

 berries. 



Dianella. Liliacece. 



Increased by seeds, sown in gentle heat during spring. 

 By divisions. 



Dianthera. See Justicia. 



Dianthus. See Carnation, Pink and Sweet William. 



Dicentra, Capnorchis, Diclytra (Bleeding Heart). Papaveraceoe. 



The crowns may be divided in early spring, or cuttings 



may be made of the fleshy roots in short lengths, and placed 



