old witchgrass vs Panicum capillare

old witchgrass and Panicum capillare both are nouns.

Word	Noun	Adjective	Verb	Adverb
old witchgrass	Yes	No	No	No
Panicum capillare	Yes	No	No	No

As nouns, old witchgrass and Panicum capillare are synonyms defined as:

old witchgrass and Panicum capillare: North American grass with slender brushy panicles; often a weed on cultivated land

Other synonyms of old witchgrass include old witch grass, tumble grass, witch grass, witchgrass.

old witchgrass (noun)	Panicum capillare (noun)
North American grass with slender brushy panicles; often a weed on cultivated land	North American grass with slender brushy panicles; often a weed on cultivated land