Answer: celandine

AnswerCrossword Clue
CELANDINE"Each monk must go to his .. alone"
CELANDINEPoppylike plant.
CELANDINEYellow-flowered plant
celandineeither of two plants (greater celandine and lesser celandine) supposed to flower when the swallows came, and to perish when they went
celandinea yellow-flowered Eurasian biennial herb (Chelidonium majus) of the poppy family naturalized in the eastern United States