Answer:

HAWTHORN

AnswerCrossword Clue
HAWTHORNTree housing Heyerdahl?
HAWTHORNHedge plant
HAWTHORNDowny ...; its blossom is state flower of Missouri.
HAWTHORNMo.'s flower
HAWTHORNHedgerow tree
HAWTHORNPrickly shrub