Zuzu, Here's what I'm basing it on.
If you go through the species entries at Kew WCSPF it notes: Lifeform: Tuber geophyte
http://apps.kew.org/wcsp/home....
At eFloras:
http://www.efloras.org/florata...
If there are more than one underground structure I've found they note it in the Genus level entry description, when there is one.
Deleting the 1 gal. container reference from the parent plant entry makes sense to me.