Butter-bean plant and Shell bean

Butter-bean plant noun - Bush bean plant cultivated especially in southern United States having small flat edible seeds.

Shell bean and butter-bean plant are semantically related. In some cases you can use "Shell bean" instead a noun phrase "Butter-bean plant".

Shell bean noun - A bean plant grown primarily for its edible seed rather than its pod.

Butter-bean plant and shell bean are semantically related. Sometimes you can replace phrase "Butter-bean plant" with "Shell bean", this phrases are similar.