Green bean and Mung bean

Green bean noun - A common bean plant cultivated for its slender green edible pods.

Mung bean is a synonym for green bean. In some cases you can use "Mung bean" instead a noun phrase "Green bean".

Mung bean noun - Erect bushy annual widely cultivated in warm regions of India and Indonesia and United States for forage and especially its edible seeds; chief source of bean sprouts used in Chinese cookery; sometimes placed in genus Phaseolus.

Green bean is a synonym for mung bean. You can use "Green bean" instead a noun phrase "Mung bean".