bitter melon 
Too bitter to be eaten raw, it is an ingredient in various kinds of Asian cooking, such as soups or steamed dishes.
zucchini 
Small white-fleshed squash picked before fully ripe; it is an essential ingredient in ratatouille.
pattypan squash 
When very ripe the flesh turns hard and white; its firm flesh has a flavor similar to the artichoke.
crookneck squash 
The soft edible rind is covered in small ridges; best if picked very early, it can be eaten raw or cooked.
straightneck squash 
The result of genetically altering the crookneck squash to eliminate the thin crooked neck; it is eaten raw or cooked.
chayote 
This squash, grown mainly in tropical countries, is used in Creole cooking; the central stone can be eaten once cooked.