horse nettle vs bull nettle

horse nettle and bull nettle both are nouns.

Word	Noun	Adjective	Verb	Adverb
horse nettle	Yes	No	No	No
bull nettle	Yes	No	No	No

As nouns, horse nettle and bull nettle are synonyms defined as:

horse nettle and bull nettle: coarse prickly weed having pale yellow flowers and yellow berrylike fruit; common throughout southern and eastern United States

Other synonyms of horse nettle include ball nettle, ball nightshade, Solanum carolinense.

horse nettle (noun)	bull nettle (noun)
coarse prickly weed having pale yellow flowers and yellow berrylike fruit; common throughout southern and eastern United States	coarse prickly weed having pale yellow flowers and yellow berrylike fruit; common throughout southern and eastern United States