32 SEPARATION AND DIVISION. 



taken that the corms do not become so cold and wet as 

 to cause them to rot. 



2. DIVISION. 



The word division is commonly applied to that phase of 

 separation in which the parts are cut or broken into pieces, 

 in distinction to propagation by means of parts which 

 naturally separate at the close of the season ; but no hard 

 and fast line can be drawn between the two operations. 

 Whilst separation is mostly concerned with bulb-like and 

 corm-like organs, division operates mostly upon tubers and 

 rootstocks. 



A tuber is a prominently thickened portion of a root or 

 stem, and it is usually subterranean. The potato, sweet 

 potato and dahlia furnish good examples. Tuberiferous 

 plants are multiplied by planting these tubers whole, or in 

 many cases the tubers may be cut into small portions, as 

 described in Chapter IV., in the descriptions of cuttings. 

 In hardy species, the tubers may be allowed to remain in 

 the ground during winter, but they are generally dug in 

 the fall and stored in a dry and cold place, but where they 

 will not freeze. 



An offset is a crown or rosette of leaves, usually borne 

 next the surface of the ground, and which in time detaches 

 itself and forms an independent plant. The best examples 

 occur in the house-leeks, plants which are more familiarly 

 known as "hen and chickens" and "man and wife." 

 These offsets take root readily, and in propagating there 

 is no other care necessary than to remove and plant them. 



A crown is a detachable portion of a rootstock bearing 

 roots and a prominent bud. Rhizomes or rootstocks mul- 

 tiply individuals and extend the distribution of the species 

 by means of a progressive movement of the crowns. The 

 rootstock grows during summer, and at the end of the sea- 

 son each branch develops a strong terminal bud, which 

 usually produces a flowering stem the following season. 

 The rootstock gradually dies away at its old extremity, 



