Apparently it’s a thing to a degree in Europe specifically Russia according to google/bing.
The artist on the comic is from Barcelona, Spain.
Spain isn’t huge into the odd numbers over even but, they are somewhat into it as far as I can tell.
My understanding the traditional funeral flower in France and for the matter Spain is the Chrysanthemum. With that said the tradition is newer in France it dates back to World War I and was more a case that it was what was still around.