In my experience as a cycad grower I frequently come across individual plants that display a single unusual characteristic that I have never seen associated with that plant in the past. In nearly all cases it turns out to be what I term as an “example of singular occurrence.” To me this means that I don’t remember seeing it happen to that plant in the past, and it hasn’t persisted in successive years, when the plant repeats the same portion of its growth cycle. When I discuss these occurrences with other cycad growers, the typical response from them is that we were observing a mutation.
I decided I needed to look up the definition of mutation. The dictionary defines it as “any heritable alteration of the genes or chromosomes of an organism.” This caused me to think that if what many of us have been characterizing as a mutation, and a mutation involves the “heritable alteration of the genes or chromosomes,” then why are these alterations or deviations not consistently displayed year after year in the plant, as do other genetic characteristics? Perhaps we are not really observing a mutation at all. Perhaps the term anomaly would be more appropriate. The word anomaly is defined as: “Deviation from the normal or common order, form or rule.” I suppose that these two definitions may be interpreted to have some degree of synonymous meaning. However as defined, a mutation can also be considered an anomaly, but an anomaly isn’t necessarily a mutation, because an anomaly doesn’t have to have a heritable change of genes or chromosomes.
Although this term anomaly may be more acceptable, by definition it still suggests no root cause that would describe what, if anything, physically has taken place to cause cycads to display the “example of singular occurrence.” For me the question remains unanswered. The many influential variables that comprise cycad culture convince me to believe that perhaps we may never be able to connect all of the dots to understand what may cause an “example of singular occurrence.”
An infrequent or unusual manifestation could be the result of any singular or combined number of abnormal or extreme conditions that the plant may experience. This must include any of a myriad of cultural variables, such as: excess or shortage of water, nutrition, heat, cold, dryness, humidity, shade, sun, pests, etc.
It occurs to me now while I ponder the many aforementioned variables that cycads are subjected to in nature, that nearly this entire list of conditions, even in their more extreme form, doesn’t really seem to be that unusual. In other words, the more time I have spent growing, the more often I have witnessed a variety of unusual or extreme examples, which ironically tend to make these occurrences less unusual.
Just perhaps in the overall scheme of things, the occasional example of “singular occurrence” isn’t a mutation or an anomaly at all, but in the big picture of the potentially long lifespan of cycads, these occurrences may be considered the norm.
All dictionary definitions are quoted from the New College Edition of The American Heritage Dictionary of the English Language.