dragonhead vs herbaceous plant

dragonhead and herbaceous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
dragonhead	Yes	No	No	No
herbaceous plant	Yes	No	No	No

As nouns, herbaceous plant is a hypernym of dragonhead; that is, herbaceous plant is a word with a broader meaning than dragonhead:

dragonhead: American herb having sharply serrate lanceolate leaves and spikes of blue to violet flowers
herbaceous plant: a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests

Other hypernyms of dragonhead include herb.

dragonhead (noun)	herbaceous plant (noun)
American herb having sharply serrate lanceolate leaves and spikes of blue to violet flowers	a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests