Roses Really Do

OutKast – Roses – 2003

video link

It’s true. Roses really do smell like the end product of our metabolism. Two major constituents of the smell of roses are Skatole and Indole, which are good olfactory representatives of excrement. They’re also used extensively in perfume.

This may or may not explain why many air fresheners (at least as far as I know since the dawn of aerosolized air fresheners) smell like roses. Regardless of whether shit and flowers go together like peanut butter and jelly, it was used a lot as an air freshener scent, at least as far as the early 90’s. (Anyone like to weigh-in here on the history of air fresheners?)

But this fact does explain why I, among others I’m sure, hallucinate excrement when smelling roses – you expect it to be there. This is called redintegration, a kind of hallucination, and it’s explained in this clip from Hidden Scents:

Part of a smell can carry with it the co-occurring odor molecules around them in the memory, and it will later be used to substitute for the whole. Strains of cannabis, aside from the strong skunk-like smell, can have significant amounts of limonene in them. Through redintegration, the potent smells of such cannabis become so tied together that upon smelling an orange (almost entirely limonene), a frequent user might hallucinate the other odors of cannabis along with the orange. This phenomenon represents an apparition superimposed in order to satisfy the nose-brains’ insistence on predicting an odor based on limited or partial information – a behavior that is not limited to olfactory perception.

Post Script

The scent of “musk” comes from the neither region of the musk deer. Just saying. Today you wouldn’t know that, because that scent of musk is now more associated with fresh laundry. Musk is a very big molecule, for a smell, and it sticks really well to your clothes even as they’re being washed, so it’s the main ingredient in laundry detergents.

When you smell “clean laundry,” you don’t think you’re smelling musk, but you are. Funny how today we associate clean with a thing that ultimately comes from an animal’s butt. (Please note that today, most if not all musk comes from a laboratory and not an animal.)

Some Flowers Smell Bad

I often associate the smell of a rose with that of solid human waste, by way of restroom air fresheners; incidentally, the reason floral smells are so good in air fresheners, is that they share similar aroma compounds, like indole and skatole. image: Glorious Garden

The secret of the world's smelliest flower

Simon Cotton, The Conversation, via phys.org, July 9, 2015

[note this post is a bit outdated]

Most people already know about the world's smelliest flower. Here I'd like just take note of its associated lexicon, taken from the above article.

First let's hear about this "master of disguise":

"Its smell is designed to attract insects such as flies and carrion beetles, which normally feed on decaying flesh, which will help pollinate it. The spathe is green on the outside but the flower head is red, so it looks like meat. This plant is really cunning – as it blooms it gives out quite a lot of heat, up to 36°C, which encourages the molecules to spread out by helping them vapourise, and also confirms the impression of "warm meat". The insects crawl over the spathe to leave their eggs in what they believe to be rotten meat, in the process transferring pollen – and this pollinates the plant."

-Amorphophallus titanum

-corpse flower

-carrion plant

-hot, rotten flesh

-dimethyl disulphide (DMDS)

-dimethyl trisulphide (DMTS)

-"disgusting"

-'off-flavor' in beer (result of the fermentation process)

-"sweaty skin" acids

-indole

-human faeces

-"dead-horse arum"

-dimethyl sulfide (DMS)

-"smell of the seaside"

-black truffles underground in some parts of France.

(DMDS and DMTS are associated with the smell of Italian white truffles.)

*This list contains terms associated with plants of similar genus, and terms for molecules that may only contribute to, but do not wholly represent, their reference-term (indole is a component of human feces, but not the only one).