Alliaceous plant and Onion plant

Alliaceous plant noun - Bulbous plants having a characteristic pungent onion odor.

Onion plant and alliaceous plant are semantically related. In some cases you can replace phrase "Onion plant" with "Alliaceous plant", this phrases are similar.

Onion plant noun - Bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb.

Alliaceous plant and onion plant are semantically related. You can use "Alliaceous plant" instead a noun phrase "Onion plant".