RE: Inflorescence Odor Changes in Response to Temperature

From: on behalf of Don Burns
Sent: 	Monday, December 15, 1997 10:15 PM
Subject: 	Inflorescence Odor Changes in Response to Temperature

>>The temperature is again tonight dropping into the low 50degF point and 
it is very windy.  Since the wind chill will probably put the effective 
temperature far below 50, once again the water dwellers will spend their 
night in the garage. The Uropspathas have a number of inflorescences most 
of which this afternoon were exuding their characteristicly sweet 
melon-like odor.  Just a few hours later, the fragrance is gone.  I know 
this is not a response to darkness, as they were quite fragrant last 
night at 11PM.

The sole other significant change that took place in the past few hours 
is the temperature: It has dropped at least 12 or 13 degF.  Has anyone 
else observed odor changes in response temperature changes?  Granted, this 
is certainly no controlled experiment I have just performed, but I do 
intend to check out what these guys smell like again mid-day tomorrow.
I am aware of plants whose flowers respond to light, or lack of it, 
to raise the intensity of flower odors, my favorite being Brassavola 
nodosa, the orchid that is pollinated by specific night flying insects. 
But I have not night heard of plants with flowers that respond to 

Dear Don,
This is interesting on two points, the first being that I have only noticed 
odur being produced by my Urospathas around late mid-morning to mid-afternoon, 
and always assumed that it was triggered by the warmth.  My plants took a hit 
from the first cold snap earlier, so none have infloresences that I can check 
The second point is odor perception in these plants.  The Urospatha sp. I have 
from the Orinoco Delta, Venez. (that I used to believe may have been U. 
sagittifolia, now I await further research), produces an odor that to me 
smells of rich, mixed fruit salad, but a LITTLE "past the prime" (stale), 
whereas the U. grandis from Tortuguero Canal in Costa Rica, when I first smelt 
them, evoked OLD childhood memories of walking under a mango tree AFTER the 
fruiting season, when the old, dry remains of fruit and skins are on the 
ground.  It was only after a visiting friend smelt this plant`s bloom and he 
suggested "cantelope !" that it registered in my consciousness that it also 
evoked this relatively unfamiliar (to me !) odor.
If possible, ask visitors or your wife to test the odor and tell you what it 
smells like to them.  I have not smelt lemon in my blooms, but lemon (the 
lemon of temperate climes) is not an odor that I can or would be able to "pull 
up" from my memory bank, as being from the tropics, our lemons smell very 
differently !  Which Urospatha was in bloom, the U. grandis or the one with 
velvety leaves from Fr. Guiana ?  I do not remember what that one smelt like, 
but know that it smelt differently to the others in my collection, as did one 
I lost (with angular petioles) from El Tigre in E. Venez.
All very interesting !

Don Burns   Plantation, FL USA   Zone 10b

Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index