Walking near Whyte Lake 2023-11-23 we noticed a faint but definite vanilla scent, very similar to crushed vanilla leaf Achlys triphylla. We narrowed it down to a bracken fern Pteridium aquilinum turned brown but still standing. With more sniffing we found about 1 in ten of the bracken near our path had that scent. The darkest brown had the strongest scent. We picked one, and after a week of drying the scent has reduced but not disappeared. A week later on another West Vancouver hike several people noticed a similar scent near a patch of bracken turned brown, but could not narrow it to any particular plant. A Google search for "+bracken +vanilla scent" turns up ads for perfume. Has anyone met this before?
I left the word "vanilla" out of my search on Duck Duck Go and came up with this page: Hay-scented fern – Forestry.com It includes Pteridium aqualinum in its list, noting that it's not a true Hay-scented fern. Most of the ferns listed are from eastern North America. There is a paper (behind a paywall) titled Essential oil composition and antibacterial activity of Pteridium aquilinum (L.) Kuhn | Biologia Futura (springer.com) I think the term "essential oil" implies fragrance.
Somewhat O/T but here's some interesting culinary information on Pteridium aqualinum. It make me want to try warabimochi. Warabi / Bracken Information, Recipes and Facts - Specialty Produce
Bracken ferns are well-known to contain a carcinogenic compound, which was addressed in the article. However, people who eat bracken fiddleheads or even live in an area where bracken ferns are abundant have been shown to have elevated levels of certain cancers. I certainly wouldn't make eating bracken fiddleheads a habit.
For locals who wish to indulge in some taste testing, matcha warabimochi is available at Konbiniya Japan Centre. I was told other flavors are available at other times. Unfortunately I can't tell you what's written on the wrapping as the text is in Japanese. If you are concerned with the potential carcinogenic factor, chances are the mochi is made from potato starch rather than bracken starch.
