Blue thistle and Herbaceous plant

Blue thistle noun - A coarse prickly European weed with spikes of blue flowers; naturalized in United States.

Herbaceous plant and blue thistle are semantically related. In some cases you can use "Herbaceous plant" instead a noun phrase "Blue thistle".

Herbaceous plant noun - A plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests.

Blue thistle and herbaceous plant are semantically related. Sometimes you can replace phrase "Blue thistle" with "Herbaceous plant", this phrases are similar.