Euphorbia exigua vs spurge

Euphorbia exigua and spurge both are nouns.

Word	Noun	Adjective	Verb	Adverb
Euphorbia exigua	Yes	No	No	No
spurge	Yes	No	No	No

As nouns, spurge is a hypernym of Euphorbia exigua; that is, spurge is a word with a broader meaning than Euphorbia exigua:

Euphorbia exigua: European erect or depressed annual weedy spurge adventive in northeastern United States
spurge: any of numerous plants of the genus Euphorbia; usually having milky often poisonous juice

Euphorbia exigua (noun)	spurge (noun)
European erect or depressed annual weedy spurge adventive in northeastern United States	any of numerous plants of the genus Euphorbia; usually having milky often poisonous juice