Rudbeckia laciniata L.
While employed at the Amsterdam Hortus Botanicus in the 1980's, one of the tasks assigned to Bob was to provide texts for the sign posts in the garden. Most of them have been replaced since, as they were deemed "too ideosyncratic", but in remote spots a couple of them can still be found.
This one reads:
The roots of this plant were considered to be the raw material for the production of the ingredient 'Romani R.' Its effect was not entirely clear. Blankaart (1698): " it is rumored that it might kill the Dogs"