pig laurel vs kalmia

pig laurel and kalmia both are nouns.

Word	Noun	Adjective	Verb	Adverb
pig laurel	Yes	No	No	No
kalmia	Yes	No	No	No

As nouns, kalmia is a hypernym of pig laurel; that is, kalmia is a word with a broader meaning than pig laurel:

pig laurel: North American dwarf shrub resembling mountain laurel but having narrower leaves and small red flowers; poisonous to young stock
kalmia: any plant of the genus Kalmia

pig laurel (noun)	kalmia (noun)
North American dwarf shrub resembling mountain laurel but having narrower leaves and small red flowers; poisonous to young stock	any plant of the genus Kalmia