dormancy; was :Re: Hippeastrum papilio

Jim McKenney
Sun, 02 Dec 2012 15:04:59 PST
I like Jim Shield's definition of "dormancy", if only because it helps to understand why the use of that word can be confusing. What I mean is that the definition is given in relatives rather than absolutes. In other words, the physiological conditions which define dormancy in one plant lineage are not necessarily indicative of dormancy in other plant lineages. The same person who describes a leafless tulip bulb as dormant during the summer probably describes an evergreen conifer as dormant during the winter (and so much for the supposed confusion of the words dormant and deciduous). Extreme xerophytes such as cactuses and other succulents spend most of the year in what to laymen seems a state of suspended animation: are they dormant? We base these decision on what is grossly observable rather than on any deep understanding of the plant's physiology.

I did not use the term deciduous (for me a word with strong woody plant connotations) and I was not confusing "dormancy" and "deciduous"! 

"Dormancy" in tulips and "dormancy" in Hippeastrum papilio (as the term is being used in this thread) produce very different gross effects in the plants in question. If you pointed to a tulip bulb and a pot of leafy (but "dormant") Hippeastrum papilio, and then asked people which was dormant, common sense would prompt almost everyone to pick the tulip bulb. And someone well versed in tulip physiology might be able to make the case that more was going on in the tulip than in the hippeastrum. The experienced grower of Hippeastrum papilio might counter with a good case for his plant. It's not a matter of right or wrong, it's just that dormancy is expressed differently in different plant lineages. 

Dormant as applied to plants is a metaphor. And since the "meta" part of the concept get conveyed better than the underlying science, we end up using the word ambiguously.  

Jim McKenney

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