Strongly scented flowers are usually white in color.

Miscellaneous and Personal Stuff I Must Share
1

My wife just made an interesting observation: Strongly scented flowers are usually white in color.
I wonder if this is widely known, or even “true.”

Googling, I get a hit that shows seven flowers well known for their scent:
[ul][li] Magnolia, white[/li][li] Lilac “White lilacs smell the sweetest”[/li][li] Freesia[/li][li] Violet[/li][li] Sweet pea[/li][li] Rose[/li][li] Gardenia, white[/li][/ul]
Some of these aren’t white. But my wife rejects Rose as a solution — although well-known for its scent, it isn’t a strong scent: the flowers my wife names create strong scents that give pleasure from many meters away. (My wife has become a Google fan, but she didn’t find the white==scented correlation on the 'Net — it popped into her head just now as we were strolling through her flower garden.)

Here are six flower trees (genus in italics) in our garden that reinforce the hypothesis:
[ul][li] Jasmine[/li][li] White champaca (Magnolia)[/li][li] Frangipani (Plumeria)[/li][li] Fiddlewood (Citharexylum) “very strong, carnation-like scent from small white flowers”[/li][li] Tuberose (Polianthes)[/li][li] Ixora, white[/li][/ul]
Our Ixora have little or no scent … because they are red and yellow. My wife told me white Ixora have a strong scent, as I confirmed with Google: “Then a slight breeze carries the scent of one of the few Ixoras that smell, the Siamese White Ixora (Ixora finlaysoniana).”

Another web page lists the 23 most fragrant flowers according to gardeners. Eleven of the 23 are white or very pale (whitish) pink or violet. (* - The page shows cream-colored Magnolia Michelia champaca as particularly fragrant, in contrast to our Michelia alba (White champaca). Apparently there’s controversy about relative fragrances in Section Michelia!)

How about it? Is there a strong correlation between strong scent and flower color? Debunk it? Bunk it?

2

Yes, it’s a well known floral syndrome. There is a correlation between floral characteristics and the sensory capabilities of the pollinators they attract.

Large white flowers with a strong floral scent generally are pollinated by moths or bats which fly at night and have a good sense of smell. Colors can’t be seen well at night, so white is the most visible color. (Also, bats are colorblind.)

Conversely, flowers that attract hummingbirds are usually red and have little odor. Birds have a poor sense of smell but good color vision. The flowers are probably red so they are less attractive to insects, which don’t see that part of the spectrum (but do see into the UV).

Pollination syndromes.

3

Hyacinths are usually somewhere in the purplish range, and have a very strong (and very pleasant) scent. I’d say that they’re certainly stronger than lilac, magnolia, or sweet peas, though I don’t have as much experience with the others. Yes, you can smell a lilac tree from across the street, but that’s because it’s a whole tree: Get that same mass of hyacinths, and you could smell it from even further away.

4

Note that you can’t go by the color of cultivated forms. Humans have bred various colors (and forms) from the original species which may not be correlated with their pollinators.

5

A fair point, but it looks like even the wild type of hyacinths is bluish.

6

I should also say that other kinds of flowers besides those pollinated by moths or bat can be strongly scented, and these will be colors other than white. Hyacinths are pollinated by honey bees, and bee flowers may be scented. Note that neither hyacinths nor honey bees are native to the US. Bee flowers are often blue or yellow, and have patterns that can only be seen in UV.

7

Thanks, Colibri and Chronos.

I’m impressed with my wife that she intuited this connection just from local flower trees she was familiar with.

Speaking of colibri, are you familiar with the poem with these verses?
…
Et d’Amérique vient le petit colibri

De Chine sont venus les pihis longs et souples
Qui n’ont qu’une seule aile et qui volent par couples

8

Honeysuckle smell quite strong and are pale to medium yellow in color. possibly, the pale yellow could be considered a cream color but definitely not white.

9

Honeysuckle are pollinated by nocturnal moths. The scent becomes stronger after nightfall. They turn from whitish to more yellowish after being pollinated.