Sometimes when you are walking in a garden or woodland you are met by a scent wafting around. Usually pleasant, sometimes not. Normally it doesn’t take long for you to track down the source be it a scented rose, wild mint, the scented petals of some tree or the many thousand other possibilities which occur in the wild.
Just occasionally the scent proves elusive and you can’t immediately track it down so you walk on and forget about it……or you don’t and it niggles away at you because you think that you should be able to answer the riddle. And I am at present working through that process.
It all started with a forest walk last winter, on a cold sharp day. Out of nowhere there was the scent of sweet curry in the air. Very strong but very local. Walk 5 paces and the scent faded. We chatted about it but never thought too much more. Then a few weeks ago I was walking up a pathway in an oak wood and there it was….strong curry scent. There was a large oak branch lying on the track and the scent seemed to be coming from it. I returned the following day and the scent was still about and strong, but as before, very local. To discount the thought that the limb may have fallen on a fungus and thus released the scent, I dragged the limb 20m down the path. The next day the scent was at the limb’s new resting place not its original spot. So this sweet curry aroma was coming from the oak but no amount of close sniffing could locate from exactly where. Friends were taken to the site to make sure a form of madness wasn’t consuming me but all agreed, curry….fenugreek.
This was the first mention of fenugreek so a jar was bought and there it was, exactly the smell that we were after. But what connection could there be between fenugreek and Quercus robur (the common oak)?
Well here goes. This is a theory not fact because I haven’t been able to find anyone or any writing that brings this together. Indeed asking some foresters at a conference at the Palace, recently, I distinctly heard sniggering as I walked away from their table after asking the question! “Daft old man” they might have been impudently chuckling to each other.
The main compound that gives Fenugreek its aroma is Sotolon. Lovage also contains sotolon hence its curry scent. The oak tree also contains sotolon and in some areas wine is matured in oak barrels, which gives the wine a fenugreek nose. What sotolon is doing in an oak tree is not entirely clear although some insecticidal properties are claimed. Why does the aroma only occur rarely and very few people have come across it?
And one morning as I walked from my house there it was again, but faint. I traced the scent this time to a Hypericum shrub and yes, some hypericum species contain sotolon.
Lactarius helvus is a European fungus that also smells of fenugreek but I am pretty sure it’s not involved here. Wrong area, too dry and you would see the fungus if it was there.
So I have a theory but if anyone reading this diary can give the definitive answer, please do. Quite a few country friends are now sniffing away on their woodland walks trying to get their first hit from fenugreek and sniff down the source.
Enjoy your next walk in an oak woodland. Innes