Musa corms

Jim McKenney
Mon, 04 Jun 2012 12:42:18 PDT
Dylan, here's the way I look at this discussion.

There are people who believe that the answer to these questions is merely a matter of definition: once the definition of corm is in place, and the definition of rhizome is in place, then the difference between the two is a difference in kind.

On the other hand, there are people (this is my camp) who believe that  what we call typical corms, as in most crocuses,  evolved from rhizomes (remembering that some crocuses produce rhizomes, too),. To this camp,  the corm is simply a much compressed rhizome. Or rather, to interject the important distinction you made when we discussed this in the past, the corm is a much compressed modular rhizome. For people in this camp, the difference between a corm and a rhizome is a difference of degree. 

Those who believe a difference in kind is involved will no doubt insist on sharp distinctions and, since such distinctions are not characteristic of the way things happen in nature, will no doubt find themselves involved in this discussion for a long time. 

Those who believe a difference in degree is involved are probably content to recognize that while  some people might consider a given structure a corm and other people  might consider the same structure a rhizome, the only fact is that it is what it is regardless of what we call it. 

Dylan, when I read what you wrote "Would you agree that it is important todiscern structures morphologically as well? I think it is important to
recognize that there is a useful degree of precision-- limited though it
may be-- in defining terms for geophyte rootstocks." 
I had to wonder if what you meant when you said "discern structures morphologically" was that things which look alike (structures discerned morphologically). even when they are analogous rather than homologous structures, deserve the same useful degree of precision of definition routinely given to homologous structures. If that is what you meant, I think I would disagree for at least two reasons. For one, if the structures in question are analogous rather than homologous, then the distinctions between them are on the level of importance of the level of the distinctions to be made between insect wings and bird wings. Yes, it is important to learn the basic distinction (your limited useful degree of precision), but is it really worth a lot of discussion? The other reason is this: a system based on analogous distinctions will always be in tension with one based on homologous distinctions; and since most people will recognize the homologous distinctions to
 be more natural than the analogous distinctions, the system of analogous distinctions will suffer a constant attrition as more and more people come to understand the homologous distinctions. 

I can't believe I wrote that on such a beautiful spring day! I need some sunshine. 

Jim McKenney 

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