The Living Materials 



51 



Fig. 16. Root of dandelion grown in culture. Callus normally 

 forms on roots of many composites on both distal and proximal 

 ends of cut or injured segments (see paired nodules at the left). 

 Leaves frequently develop from these calluses (upper left). This 

 is in shari> contrast to the behavior of callus on plants which 

 proliferate only at the distal ends of segments. 



