dragon's head vs dragonhead

dragon's head and dragonhead both are nouns.

Word	Noun	Adjective	Verb	Adverb
dragon's head	Yes	No	No	No
dragonhead	Yes	No	No	No

As nouns, dragon's head and dragonhead are synonyms defined as:

dragon's head and dragonhead: American herb having sharply serrate lanceolate leaves and spikes of blue to violet flowers

Other synonyms of dragon's head include Dracocephalum parviflorum.

dragon's head (noun)	dragonhead (noun)
American herb having sharply serrate lanceolate leaves and spikes of blue to violet flowers	American herb having sharply serrate lanceolate leaves and spikes of blue to violet flowers