Re: What is the meaning of green and greens in these phrases?
Some vegetables come in different colors. There are red beans, black beans, yellow beans, green beans and brown beans. Bell Peppers come in red, green, yellow and chocolate (brown). Other peppers come in different colors as well, but usually when a color is mentioned, they mean Bell Peppers.
The tops (leaves) of some plants like mustard and turnips are eaten. On big cultural difference between the north and south is that Southerners eat the greens of the turnip and feed the roots to the pigs where the Northerners eat the roots and feed the greens to the pigs.
Spring onions are like new potatoes, they are harvested when young and small.