182 



AGRONOMY 



Typical forms for propagation. The branches of almost any 

 plant may strike root under favorable circumstances, but in 

 plants that depend very much upon vegetative methods there 

 are usually well-defined parts developed for the work. Several 

 of these have received distinctive names, such as sucker, stolon, 

 offset, tuber, rootstock, bulblet, and cormel. A snicker is pro- 

 duced by an adventitious bud upon some underground part, 



usually a root. Many 

 plants, among which 

 may be mentioned the 

 lilac, plum, locust, and 

 white poplar, sucker 

 freely. In such species 

 injury to the root or 

 cutting back the top 

 may induce suckering. 

 A stolon is a slender 

 branch that bends over 

 and roots at the tip, as 

 in the black raspberry, 

 currant, June berry, 

 and golden bell. The 

 offset is a short, thick, 

 horizontal branch, either 

 on the surface or un- 

 derground, which pro- 

 duces a plant at the tip. It differs from a stolon chiefly in 

 being shorter and thicker and designed solely for reproduction. 

 The century plant, house leek, and ostrich fern produce nu- 

 merous offsets. Runners differ from offsets mainly in being 

 slenderer and longer, and in producing new plants at each node, 

 as in the strawberry. Tubers are short, much thickened under- 

 ground branches that lie in the soil over a season of cold or 

 drought and produce new plants upon the return of a more 



FIG. 131. Base of a sunflower stem showin 

 offsets for reproducing the plant 



