hound's-tongue vs Cynoglossum virginaticum

hound's-tongue and Cynoglossum virginaticum both are nouns.

Word	Noun	Adjective	Verb	Adverb
hound's-tongue	Yes	No	No	No
Cynoglossum virginaticum	Yes	No	No	No

As nouns, hound's-tongue and Cynoglossum virginaticum are synonyms defined as:

hound's-tongue and Cynoglossum virginaticum: perennial shrub of North America having coarse tongue-shaped leaves and pale-blue to purple flowers

hound's-tongue (noun)	Cynoglossum virginaticum (noun)
biennial shrub of Europe and western Asia having coarse tongue-shaped leaves and dark reddish-purple flowers	perennial shrub of North America having coarse tongue-shaped leaves and pale-blue to purple flowers
perennial shrub of North America having coarse tongue-shaped leaves and pale-blue to purple flowers