yellow asphodel vs king's spear

yellow asphodel and king's spear both are nouns.

Word	Noun	Adjective	Verb	Adverb
yellow asphodel	Yes	No	No	No
king's spear	Yes	No	No	No

As nouns, yellow asphodel and king's spear are synonyms defined as:

yellow asphodel and king's spear: asphodel with leafy stem and fragrant yellow flowers

Other synonyms of yellow asphodel include Asphodeline lutea.

yellow asphodel (noun)	king's spear (noun)
asphodel with leafy stem and fragrant yellow flowers	asphodel with leafy stem and fragrant yellow flowers