capitulum
ca.pit.u.lum \k*-'pich-*-l*m\ \-l*\ n or ca.pit.u.la [NL, fr. L, small head] pl 1: a rounded protuberance of an anatomical part (as a bone) 2: a racemose inflorescence with the axis shortened and dilated to form a r ounded or flattened cluster of sessile flowers