Some similarities to : Yarrow but although the petals are crimped as they are in Yarrow, there are three more of them, and the leaves are totally different.
The flowers have a passing resemblance to those of Feverfew, but the outer petals are even fewer in number than they are in Feverfew, numbering nominally eight but can be anything from 5 to 12. Also, un-like the outer petals of Feverfew, those of Sneezewort in the fruiting stage droop downwards slightly like the pleated skirt of a girl moderately twizzing around. The central florets in Sneezewort are a cream colour, whereas they are a brilliant yellow in Feverfew.
Distinguishing Feature : The crimped appearance of the petals surrounding a largish creamy coloured button with many dimples on the surface. Also, many of the flowers have petals that are reflexed downwards away from the top in a conical fashion.
Not to be confused with:
Sneezeweed (Helenium autumnale), which has larger yellow to purplish-brown petals and although it belongs to the same Family Asteraceae, is of species Helenium.
The strongly pungent smell is said to induce sneezing, indeed the dried and powdered leaves have been used as a sneezing powder. An essential oil can be extracted which is used medicinally (although your author has yet been unable to track down the chemical ingredients of this oil). Although its bitter tasting leaves have been used in salads, the plant is poisonous to some farm animals like horses and cows, with symptoms slow to develop, which include fever, tachycardia, difficulty breathing, weight loss, drooling, spasms, and convulsions.
homoSpilAnthol is a
SpilAnthol found both in Sneezewort and in Yarrow (Achillea millefolium). They are N-AlkylAmides and are the substances responsible for the medicinal properties of both of these species. Fourteen differing N-AlkylAmides have been found in Sneezewort and 15 in Yarrow.
Two of those N-AlkylAmides in Sneezewort have never before been found: HomoSpilAnthol (which is deca-2E,6Z,8E-TriEnoic Acid 2-MethylButylAmide) and a related isomeric compound called deca-2E,4E-dienoic Acid N-MethylIsobutylAmide.