1 hour ago, Baron d'Apcher said:"Curly endive" (Cichorium endivia). It's what most in the US call chicory and is more or less unremarkable. Like an unruly head of frisée.
Escarole has wider, flatter leaves.
Puntarella is very different.
There is a photo of puntarelle on the wiki page for endive, if you scroll down. I've not seen putarelle in person, but if the wiki photo of it is correct, what @liuzhouhas is indeed a different vegetable.
I call what liuzhou has curly endive, and yes, escarole is different too, at least in my understanding, and how it is marketed under that name here. The first image in this set of them, is what is sold as escarole here. There is much confusion, though, and not just
on liuzhou's part.
I use curly endive (or whatever it is?) in a soup inspired by Marcella Hazan's recipe for Escarole and Rice Soup, only use beans instead rice. I substitute a can of usually chickpeas, but I've also used pinto and cannellini beans, for the rice. I prefer escarole for this soup, but the curly endive is a fine substitute, if I can't find escarole. A tip from the original version in Marcella's book, "The Classic Italian Cookbook": soup can be made ahead, but stop at the step where you add the rice, because it will get mushy if stored in the soup. You can make the whole thing ahead if using beans. The leftovers in the bean version are good. I really like this soup with chickpeas, and have made it with rice, but it was just okay to me. An observation from me: I find that I don't need to simmer the escarole over fifteen minutes vs. the longer cook called for in both the original and the linked versions of the recipe.