In article , david david@abacusnurse
ries.freeserve.co.uk writes
Always thought French Beans had fibrous roots.....now Runner beans form a
tuber and used to be lifted stored, then planted early to give a light crop
of early beans.

French bean roots have nitrogen fixing nodules which make them look
tuberous.
--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/garden/