alkali grass vs Zigadenus elegans

alkali grass and Zigadenus elegans both are nouns.

Word	Noun	Adjective	Verb	Adverb
alkali grass	Yes	No	No	No
Zigadenus elegans	Yes	No	No	No

As nouns, alkali grass and Zigadenus elegans are synonyms defined as:

alkali grass and Zigadenus elegans: plant of western North America having grasslike leaves and greenish-white flowers

alkali grass (noun)	Zigadenus elegans (noun)
plant of western North America having grasslike leaves and greenish-white flowers	plant of western North America having grasslike leaves and greenish-white flowers