scarlet pimpernel vs pimpernel

scarlet pimpernel and pimpernel both are nouns.

Word	Noun	Adjective	Verb	Adverb
scarlet pimpernel	Yes	No	No	No
pimpernel	Yes	No	No	No

As nouns, pimpernel is a hypernym of scarlet pimpernel; that is, pimpernel is a word with a broader meaning than scarlet pimpernel:

scarlet pimpernel: herb with scarlet or white or purple blossoms that close at approach of rainy weather
pimpernel: any of several plants of the genus Anagallis

scarlet pimpernel (noun)	pimpernel (noun)
herb with scarlet or white or purple blossoms that close at approach of rainy weather	any of several plants of the genus Anagallis
	European garden herb with purple-tinged flowers and leaves that are sometimes used for salads