In fact, the smell is definitely not floral in any way - unless the flower is Deadly Nightshade.
But the DEAD bit is correct. I'm pretty sure the smell is dead mouse - although it could be dead vole - or dead lizard. I found a lizard tail on the floor the other day, so it could be the rest of that reptile!
Meanwhile I'll continue with the lavender hearts and leave the search for the cadaver until later!