I had to laugh at the idea of a child getting rhubarb when they have been in trouble - that is sour! Too bad about the plant-that-is-not-Jerusalem-artichoke! It makes me feel so fortunate to have so many books and other resources for identifying plants. When I was younger, information was a lot more difficult to find about so many plants, too. I was fortunate to have people to teach me some plants, like this Curly Dock. You are that person for your community, I think -- and for us here on Steemit! But I have learned so much more from books over many years, too.

You might be interested in this resource about Curly Dock from the Invasive Species Specialist Group. They say this plant is in the top five most widely distributed plants in the world. And maps I have seen show it being all through Central America -- and it is on plant lists for Costa Rica and Panama. Here are some other names -- maybe you will recognize one:

acedera crespa (Spanish), acedera crispada (Spanish), romaza crespa (Spanish), gualtata (Spanish), vinagrillo (Spanish), acelgas (Spanish), lengua de caballo (Spanish), romaza (Spanish), lengua de vaca (Spanish)