hypanthium

noun

hy·​pan·​thi·​um hī-ˈpan(t)-thē-əm 

plural hypanthia hī-ˈpan(t)-thē-ə 

: an enlargement of the floral receptacle bearing on its rim the stamens, petals, and sepals and often enlarging and surrounding the fruits (as in the rose hip)

Word History

Etymology

New Latin, from hypo- + anth- + -ium

First Known Use

circa 1855, in the meaning defined above