trillium, wood lily, wake-robin(noun)

any liliaceous plant of the genus Trillium having a whorl of three leaves at the top of the stem with a single three-petaled flower

jack-in-the-pulpit, Indian turnip, wake-robin, Arisaema triphyllum, Arisaema atrorubens(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

Wake-robin(noun)

any plant of the genus Arum, especially, in England, the cuckoopint (Arum maculatum)