REPRODUCTIOISr BY STEMS AND LEAVES 



85 



of the earliest blooming herbaceous kinds, such as squills, 

 hyacinths, tulips, crocuses, and snowdrops, are grown from 

 bulbs or other forms of underground stem. The commonest 

 of all instances of propagation by this kind of stem is that of 

 the potato, which is never grown from seed except for the 

 production of new varieties. jVs every farmer and market gar- 

 dener knows, each potato will produce as many new plants as 



it has buds ("eyes"); though 

 ' /^'Jf^iP^ it i^ better not to cut the 

 potato into too small pieces 

 for propagation, or the plants 

 ■will grow slowly at first. 



Tig. 68. Propagation of the strawberry plant by runners 

 A, the parent plant; B, the young plant; r, runner; 6, bract. Half natural size 



77. Reproduction by offsets and similar branches. An offset 

 is a lateral branch for vegetative reproduction, usually rather 

 short, as seen in the cardinal flower and the houseleek. Some- 

 times the offset ends in a leafy rosette ; in any case the branch 

 readily takes root and begins life as a new individual. 



A stolon is an ordinary branch which roots at or near the tip 

 and so forms a new plant, as is often seen in the black raspberry. 

 A runner is a very slender stolon, leafless except near the tip, 

 where it roots and grows into a new plant, as in the straw- 

 berry (Fig. 68), the silverweed, and other cinquefoils.^ 



1 The word runner is also used, for lack of a better term, for the slender 

 underground steins shown in Fig. 66. 



