jack-in-the-pulpit vs arum

jack-in-the-pulpit and arum both are nouns.

Word	Noun	Adjective	Verb	Adverb
jack-in-the-pulpit	Yes	No	No	No
arum	Yes	No	No	No

As nouns, arum is a hypernym of jack-in-the-pulpit; that is, arum is a word with a broader meaning than jack-in-the-pulpit:

jack-in-the-pulpit: common American spring-flowering woodland herb having sheathing leaves and an upright club-shaped spadix with overarching green and purple spathe producing scarlet berries
arum: any plant of the family Araceae; have small flowers massed on a spadix surrounded by a large spathe

Other hypernyms of jack-in-the-pulpit include aroid.

As nouns, arum is a hypernym of jack-in-the-pulpit; that is, arum is a word with a broader meaning than jack-in-the-pulpit:

jack-in-the-pulpit: common European arum with lanceolate spathe and short purple spadix; emerges in early spring; source of a starch called arum
arum: any plant of the family Araceae; have small flowers massed on a spadix surrounded by a large spathe

Other hypernyms of jack-in-the-pulpit include aroid.

jack-in-the-pulpit (noun)	arum (noun)
common American spring-flowering woodland herb having sheathing leaves and an upright club-shaped spadix with overarching green and purple spathe producing scarlet berries	any plant of the family Araceae; have small flowers massed on a spadix surrounded by a large spathe
common European arum with lanceolate spathe and short purple spadix; emerges in early spring; source of a starch called arum	starch resembling sago that is obtained from cuckoopint root