David, Yes, a tuber is a special sort of stem. But because plants enjoy confounding our best efforts to "pigeonhole" them, there are cases where stem tissue may be transitional to root tissue. One South African Dioscorea sp. was found to possess both root and stem tissue (at the anatomical level) mixed within its rootstock. Potatoes are interesting in that they propagate by stolons and form a larger network for a single plant (please correct me if I'm wrong on this). What could be called a more 'orthodox' tuber is solitary, static and accumulates mass over time-- Cyclamen, many Sinningia, Begonia x hybrida, etc. Dylan On 4 June 2012 12:05, David Ehrlich <idavide@sbcglobal.net> wrote: > Gosh, in elementary school I was taught that a tuber is a stem, not a > root. Of > course, the only tubers that New York City schoolchildcren were likely to > be > familiar with were potatoes, where the tuber is a stem -- I think. > > David E. > > > > > ________________________________ > From: Peter Taggart <petersirises@gmail.com> > To: Pacific Bulb Society <pbs@lists.ibiblio.org> > Sent: Mon, June 4, 2012 4:39:43 AM > Subject: Re: [pbs] Musa corms > > I was taught that a tuber is a swollen root and that a rhizome is a swollen > stem. > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ > -- "*Reason is itself a matter of faith. It is an act of faith to assert that our thoughts have any relation to reality at all.*" ~ Gilbert K. Chesterton