Hawthorn

The blossom of the Hawthorn is very red this year

To prove an old superstition - unlucky to bring flowering Hawthorn indoors - it has been discovered that the flower's sweet scent is also produced during the decay of corpses.

I prefer the little rhyme:

Beware the Oak –
it courts the stroke.
Beware the Ash –
it courts the flash.
Creep under the thorn –
it will save you from harm.