hound's-tongue vs herb

hound's-tongue and herb both are nouns.

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

As nouns, herb is a hypernym of hound's-tongue; that is, herb is a word with a broader meaning than hound's-tongue:

hound's-tongue: biennial shrub of Europe and western Asia having coarse tongue-shaped leaves and dark reddish-purple flowers
herb: a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests

Other hypernyms of hound's-tongue include herbaceous plant.

As nouns, herb is a hypernym of hound's-tongue; that is, herb is a word with a broader meaning than hound's-tongue:

hound's-tongue: perennial shrub of North America having coarse tongue-shaped leaves and pale-blue to purple flowers
herb: a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests

Other hypernyms of hound's-tongue include herbaceous plant.

hound's-tongue (noun)	herb (noun)
biennial shrub of Europe and western Asia having coarse tongue-shaped leaves and dark reddish-purple flowers	aromatic potherb used in cookery for its savory qualities
perennial shrub of North America having coarse tongue-shaped leaves and pale-blue to purple flowers	a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests