Re: Tuber vs. Corm
At 06:58 PM 1/11/99 -0600, you wrote:
>I was talking with a Ph.D Botanist (name withheld for obvious reasons) who
>is a recognized authority on different types of bulbs.... He said, when I
>asked him, that Amorphophallus is a corm and not a tuber or bulb. I think
>he said something about the cell structure.....
>Do we want to start this discussion again....???
>Which is it?
>Dewey E. Fisk, Plant Nut
>THE PHILODENDRON PHREAQUE
>Your Source for Tropical Araceae
I don't know what definition your botanist was using, but I define a
corm as a compressed, usually subterranean, modified stem that is
surrounded by dry, scale-like leaves. A tuber is a thickened, compressed,
more or less fleshy, usually underground stem. Using these definitions,
the modified underground stems of the species of Amorphophallus are tubers.
I have not seen any evidence of the modified stems being surrounded by
dry, scale-like leaves. The problem is that some of the tubers have a
corm-like shape with a large apical bud. From what I have seen of the
genus, the underground stems are quite varied. Some look very much like a
rhizome, some look like the "typical" tuber, and others look like corm. We
are looking at a continuum here, and definitions, at least simple ones that
you learn in school, usually only cover the usual, most common conditions.
The thing that I think is important is looking at the range of
modifications, then I think that it is obvious that they are tubers. That
is this Ph.D.'s two-cents worth.
Paul M. Resslar
Professor of Biology
Virginia Wesleyan College
1584 Wesleyan Drive
Norfolk, Virginia 23502-5599