Abstract
Eriocaulon itapevense, a new species from the Coastal Plain grasslands of Southern Brazil, is described and illustrated. The new species is morphologically similar to E. magnificum, from which it differs mainly by the pubescent and opaque-green to greyish leaves, spathes and scapes, the strongly cucullate and pungent leaf apex, the longer lateral slit of the spathe, the longer and wider involucral bracts, and the rhombic-spathulate median petals of the pistillate flowers. The description of the new species is accompanied by photos and line drawings, information on geographical distribution, habitat and a conservation status assessments. Additionally, we provide an annotated checklist and an identification key for the Eriocaulaceae from the Coastal Plain grasslands of Southern Brazil. Our checklist comprises five genera and nine species, including Eriocaulon arechavaletae and Paepalanthus planifolius, which are new records for this region.