VEGETATIVE REPRODUCTION 155 
2. By Creeping Stems, Runners, Suckers, and Offsets.— 
Stolons, or runners, are weak prostrate shoots, lying upon 
the surface of the ground, which root at their extremity, 
while the terminal bud gives rise to an erect stem bearing 
leaves—e.g., strawberry (Fig. 56). Suckers are under- 
Fic. 56.—RUNNER OF THE STRAWBERRY. 
ground branches which ultimately turn up and enter the 
air as vertical stems—e.g., mock-orange, rose, raspberry. 
In some cases buds arise adventitiously on roots, and form 
suckers—e.g., elm (Fig. 57), poplar, hawthorn, lilac, rose, 
raspberry, barberry, apple, plum, apricot, peach, etc. 
The connections may ultimately die, and the new plants 
Fic. 57.—Sucker oF Exim. 
consequently lose connection with the parent. Cutting 
down the plants to the ground, or uncovering the soil so 
as to expose the roots to the air and the light, stimulates 
the formation of these buds. Offsets are short runners— 
e.g., houseleek (Fig. 58), London-pride. These are rosette- 
plants ; short stolons arise from the axils of the outer leaves, 
