This is all about chemistry and genetics. But nothing on 'why roses smell nice'.

It's really a puzzle. Why on earth should Homo Sapiens consider a rose's smell to be 'nice'? Dogs like roses' smell about the same as shit. They don't give a damn.

Further, why are rainbows pretty? Why is a waterfall inspiring? And on and on.

You have to have some kind of special model to explain this, I think. Something beyond simple reproductive survival. But I don't know what.

Anyway, interesting that we all smell slightly differently! So indeed qualia is a bigger issue than we may have thought.

I've seen the argument before that humans find flowers pretty because they indicate fertile land, where there are flowers there will be animals, etc. Impossible to really know, I suppose.

Anyone who's done any gardening would find that fertilizer - both natural and otherwise - do not smell pleasant.

Fertile land exists naturally without the manual addition of manure fertiliser.

...and smells much the same!

our monkey brain this mean fruits later, maybe.

It could possibly be ancestral from some specie that relied on flowers in a more direct way.

Rainbows then? A pretty rock? A lone tree on a remote hilltop illuminated by a sunrise?

These are definitely higher order experiences (requiring perhaps consciousness) that have nothing to do how your olfactory nerves were once wired.

Arboreal human ancestors ate a lot of fruit.

Not all rose types smell as nice as others. There are countless types, all bred for specific characteristics over hundreds of years.

If one such characteristic is pleasant smell (and why would it not be), then the answer is obvious. By and large, roses smell nice because human bred them to.

That may explain why roses smell nice, but many wildflowers smell nice too.

> By and large, roses smell nice because human bred them to.

That theory seems unlikely to me since wild roses smell good.

I would say that the modern roses that don't smell good have instead lost their smell because they were selected on other criteria.

Dogs actually are quite interested in the smell of shit.

Your rose smells nice because it was bred to smell nice by human breeders. All the different varieties of cultivated roses that we have today are the product of hybridizing and selective breeding (“artificial selection”) of twelve or so wild rose species; a process that has continued over hundreds if not thousands of years.

While not a hard and fast rule, most plant species with strongly scented flowers usually are white (jasmine, gardenia, etc.) and pollinated by nocturnal animals like moths and bats. (A great counter-example is corpse flowers, which use scent to attract a completely different guild of pollinators).

Where I live roses grow wild and always have. They smell as good as cultivated roses.

Do you believe these "wild" roses have never cross-fertilised with cultivated varieties?

Seems unlikely. They line the roads currently and are referenced by settlers when they first came to the area in the 1860s

So-called white flowers are in a bit of their own category, as perfume goes. A _white floral_ is conventionally the flowers you named (I'd add tuberose and orange blossom as commercially important) and have startlingly similar scent profiles. Importantly, they all contain a lot of indoles, which is also in feces so they're sometimes described as fecal or dirty, and has something to do with why they are such conspicuous odors. As a perfume for wearing, they go through pronounced trend cycles.

There are many others of interest. Roses of course but also violet, lavender, lilac, lily, hyacinth, osmanthus, mimosa, marigold, chrysanthemum, chamomile, geranium, carnation. You might count iris, but moreso the tuber than the flower.

I find it extremely difficult to reliably find roses for sale that actually smell like anything at all.

Here’s 206 roses trees varieties ready to order [0]. GF is a lot into flowers and got a lot of stuff from this store, highly recommend them for any plant, great quality and care. Europe only I guess.

[0] https://www.promessedefleurs.com/rosiers/rosiers-parfumes.ht...

I don't see any varietal in there that I can't get from any other store that also doesn't have any scent.

I don’t doubt you’re more knowledgeable than me but if you can’t smell ”any sent” from 200+ “fragrant roses” varieties maybe the problem is to look elsewhere ? Maybe your odorat or your expectations ?

I do smell perfume from certain roses trees as well as does my GF and the roses gardener in this beautiful place [0]. Don’t think smelling roses perfume is a rare condition. Also you probably already know that food additives and ambiance perfumes smells roses like a banana candy taste banana.

I wish you success in your search.

[0] https://albert-kahn.hauts-de-seine.fr/en/collections/present...

Marketing can call a rose "fragrant" all it wants. That doesn't make it so.

I have bought almost every kind of varietal I can lay my hands on in an attempt to find roses with scent for my wife's birthday for 20+ years now. When I started doing this, it was easy to find varietals with scent--some of them would pump the whole house full of it they were so strong. In the last 5 years, even if I buy a scattering of varietals (generally I will buy 4-6 dozens in an attempt to find one), I have come up empty twice.

If, however, I go to something like the Del Mar fair and examine the roses which are called "fragrant", they actually are.

I'll leave the conclusions to you.

Most home garden friendly roses are bred for disease resistance, climate, pest resistance, and flower production. Scent isn't in there.

I have a 'Honey Perfume' that smells nice, but most of the other varieties I have only have very faint scents.

I concur. Even roses which are extremely expensive and nominally "highly scented" don't smell at all, anymore. I used to have to go on a hunt for a varietal with scent, and now even with a lot of hunting, I can't find them anymore.

The problem is apparently that some enzyme that makes scent also tends to break down the flower. So, the "lifetime" of a cut rose is inversely dependent upon the volume of scent.

And, since everything is shipped around the world from the absolute lowest cost area, "lifetime" becomes the only goal with everything else being secondary.

Thus, we have roses with no scent.

Is this a new development in the last couple years?

Covid!

As a completely random aside, I was in a social gathering this week, some people were talking about roses, and I overheard: "Of course the smell has been bred out of roses."

Is this the organic/classy version of amazon yankee candle reviews?

In the UK it is very easy to find scented roses from specialist growers. David Austin for instance has a 'Best for Fragrance' category on their website. They even go into some detail in describing the smells.

I find that scents don't last too long, but I think this is to be expected. On my property most of the scent from roses is produced in the first week's bloom before dissipating.

If they didn't smell nice we wouldn't have domesticated them and planted them all over.

Lots of flowers that don't smell like much get planted all over the place.

Or worse, Bradford Pears - popular ornamental trees with pretty flowers for public roads, and they smell offensive

They are markers on the map. It is like "Can you drink a river ?"

I once stayed at a hotel next to one of the largest rose gardens in the southern hemisphere, with hundreds of varietals.

I walked through smelling every unique type of rose flower and I was surprised to learn that the vast majority do not smell like “roses”!

A rough estimate was that half smell bad or not at all, most of the rest smell like lemons, and a few percent only have the prototypical rose smell.