That is the Universal Edibility Test and gets repeated ad nauseam in all the survival circles. You would miss out on some fine choice foods if you did that.
Stinging Nettles (Urtica dioica) is one of them. Pokeweed (Phytolacca americana) too.
Source - used to teach these skills before it was cool to be a "survivalist" on TV and social media.
Yes I don't know how someone figured out that if you cook pokeweed and change the water multiple times then you can finally eat it without it killing you.
Source - used to teach these skills before it was cool to be a "survivalist" on TV and social media.