Paeone post script - Fragrance

Lee Poulsen
Thu, 15 May 2008 22:38:43 PDT
On May 15, 2008, at 5:32 PM, Robin Bell wrote:

> However, I have come to the conclusion
> that this is such a subjective thing, that it is almost beyond
> comprehension: even for two people standing in front of the same
> plant.

> Certainly we are at, or close to, the bottom of the pack. That is why
> I am very suspicious of this as a criterion for plant I.D. unless
> it's based on machines such as gas chromatography.

> I don't know whether a plants
> fragrance is modified by cultural conditions, but, considering how
> many other aspects are, it would be hard for me to believe that it is
> not. Surely, at least as likely to compound the issue is individual
> (human) variation.

I know that to a certain extent, smell is subjective. And the sense of  
taste is also greatly affected by the sense of smell. In fact, I  
remember from long ago in high school biology class when we arrived in  
class and there were small paper strips on everyone's desk. At a  
certain point, the teacher told everyone to place the strip on our  
tongues. Immediately, more than half the class spit out the paper and  
made sounds of disgust, while the remaining students stared at their  
classmates in bewilderment because they couldn't taste anything at  
all. It turns out that a significant percentage (of Americans?) do not  
have the gene to be able to detect/taste this particular compound--at  
all. For the majority who do have the gene, it tastes very bitter.  
Since smell is a significant part of our ability to taste, it doesn't  
surprise me that different people can have different reactions to the  
same esters or other compounds that go into making the fragrance of a  
particular flower. It can also explain why some people don't smell any  
fragrance at all in some flowers that many others do detect. The point  
is that there are some fragrances that a large majority of all humans  
can detect that shouldn't be ignored just because a minority of humans  
can't detect it. Should we ignore the colors of some flowers just  
because a minority of humans can't see or distinguish certain colors?

Now whether it's a pleasant fragrance or not may well be a matter of  
cultural conditions. So I can understand reticence with which  
adjectives might be used to describe the fragrance. However, I think  
that if a majority can detect the fragrance it ought to be noted just  
as a majority can detect certain tastes such as sweet or bitter or  
sour, and foods or fruits can certainly be aptly described including  
descriptions of taste.

And while I still love flowers that have no fragrance that I can  
detect, for many reasons other than the fragrance, I also equally love  
flowers whose fragrance may be their most notable characteristic. So I  
am in the other camp that wonders why fragrance isn't also always  
included as yet one more component of a species' ensemble of  
characteristics. IMNSHO, I think it's just as important as how long or  
wide the tepals are or the peduncle or some other part of the flower.  
Just because some people can't detect the fragrance doesn't mean it's  
not important; it just makes it a more difficult characteristic to  
describe if you happen to be the botanist who is describing a new  
species and just happen to be missing a gene that allows you to detect  
the fragrance, even if the large majority of humans CAN detect it. It  
frustrates me to no end to read about a species new to me that doesn't  
have an appearance or other visible quality that strikes my fancy and  
so I turn down the opportunity to obtain it, only to discover some  
time later after the opportunity has passed that it has an amazingly  
wonderful fragrance that would have made me instantly snatch it up,  
but that was never mentioned in its description.

(And yes, there are some scents that I don't find pleasing that others  
do (e.g., "paperwhite" Narcissus), or that are too strong and so  
rapidly become unpleasant in enclosed spaces. But some of these I love  
when growing in the right setting for that plant. One that always  
comes to mind is the one called night blooming jasmine (Cestrum  
nocturnum). I would never have chosen to grow this based on what the  
plant or its flowers look like. The flowers are very small and too  
pale greenish for my tastes and the plant is tall and gangly. And  
while it is too strong and unpleasant up close for me to ever bring a  
"bouquet" of the flowers inside in a vase, to me it is intoxicating to  
step outside into a yard on a warm summer night where one of these  
plants is blooming somewhere in the yard.) On the other hand, I was  
just as entranced the first time I saw a raceme of Strongylodon  
macrobotrys ("Jade Vine") in bloom. (Some of my friends I showed the  
blooms to at the Huntington this year thought it was merely an  
interesting curiosity and kind of weird.)

--Lee Poulsen
Pasadena, California, USA, USDA Zone 10a

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