438 



HOW PLANTS ARE SCATTERED 



412. Dispersal of seed plants by bulblets. Almost every 

 farmer's boy knows what " onion sets " are. This name is often 

 given to little bulbs produced at the top of a naked flower stalk, 

 or scape, by some kinds of onions which do not usually flower 

 or bear seed. Tiger lilies produce somewhat similar bulblets in 

 the axils of the leaves, and there is a large number of species, 



FIG. 338. Fruit of smoke tree (Rhus Cotinus) 



Only one pedicel bears a fruit, all the others are sterile, branched, and covered 

 with plumy hairs 



scattered among numerous families of plants, all characterized 

 by the habit of producing bulblets or fleshy buds, borne on the 

 stems or leaves above ground and of use in propagation. When 

 mature the bulblets fall off readily, and if they find lodgment 

 on unoccupied soil they grow readily into new plants. Some- 

 times they are carried moderate distances by wind or water, 



