Why do only some orchids have a scent

[mimigirl]

does an orchid that is fragrant have to be pollenated to be fragrant? If an orchid has a fragrance does that mean it was pollenated? help

[Tschimm]

No.
The fragrance attracts pollinators. So once the flower is pollinated, actually it doesn't need to be fragrant anymore 😉

[Leafmite]

Orchids do what they need to do to attract the pollinator they require. So, if they don't need a fragrance to attract a pollinator, they don't emit one.
Some orchids mimic other flowers, some mimic a potential mate (Mormolyca ringens), some put out a powerful sweet night fragrance to attract moths and some, like a few famous bulbos, might smell and look, to a beetle or fly, like rotting meat.

A different reason, though, is that some orchids, through breeding for other traits needed to win awards at shows, have lost the fragrance typical of the original species. This is happening also with roses, carnations and many other types of flowers. It is surprising how many new varieties of roses no longer have a fragrance. :|

[Stray59]

Hello everyone, just wanted to chime in here - I was reading that there is a theory of "rewarded" and "unrewarded" orchids. If the flower produces nectar or wax that insects utilize, often those flowers do not produce a scent. If the flower does produce a scent, there is little or no "reward" of nectar or wax. This is debatable, but it seems to be a "rule of thumb" among those that study such.
I agree with leafmite that an orchid will do whatever it needs to in order to attract a pollinator, just as the bee orchid (Ophrys apifera) has evolved a lip that looks so much like the Tetralonia cressa bee that the males try to mate with it and thus carry pollen from plant to plant. Orchids are tricky little plants!
And I cannot stand that they have bred the fragrance out of roses - IMO, if they don't smell, they do not represent roses. They seem "soul-less" to me!

[Leafmite]

Stray, I agree. My father's hobby has always been roses...fragrant tea roses. He was surprised a few years ago when most of the new roses from J&P were not fragrant. Years ago, the fragrance was considered very important to roses but, now, it is petal count, coloring, and size.

[Stray59]

Way off subject, but that is why I only plant antique or antique reproduction roses and English roses - very hard, phenomenal shape (old cabbage, quartered, buttoned, etc) and fragrances that just blow your nose off your face. With so many options, I only choose fragrant roses and fragrant orchids, unless it is something really spectacular!
Have a great spring - hope you find some good smelling roses in bloom...

[Paul]

Ah, but then there are those who are more than happy to have scentless roses! There are many scented roses that I cannot tolerate being in close proximity to for any length of time -- those with a more ... pungent ... fragrance will give me a splitting headache.

[Stray59]

Paul:
To each his own - there is a flower lover for every type of plant it seems!
I cannot imagine not being able to enjoy the stronger fragrances of roses - or orchids for that matter.
Sorry about the headaches - that has to be tough!

[Orchid Whisperer]

In roses, I prefer the old-fashioned scented roses. If you have never smelled a 'Mister Lincoln' or a 'Chrysler Imperial', you are missing out!

[Leafmite]

Sorry to hear this, Paul. You'd probably love my mounted Brassavola nodosa...no fragrance at all. I bought a second one and am hoping for a different result.

I collect mostly fragrant orchids and I also like other fragrant flowers (lilac, hyacinth, jasmine, gardenia, citrus, etc.) and plants with fragrant leaves (allspice, cinnamon, hazelnut, herbs). Where orchids are concerned, when I get a clone that isn't fragrant, I often find a home for that one and try again. Or, I just buy multiple seedlings and keep the one(s) that are fragrant. I do have a few orchids that are not fragrant but most of mine are.

Mr. Lincoln is one of my favorite roses. I am hoping that my Mr. Lincoln and Pink Peace survived the winter.