Line drawing of Heteranthera catharinensis C.N.Horn & M.Pell. A Detail of the leaf blade B Detail of the apex of the stem, showing the ligule and an inflorescence at anthesis C Detail of the basal bract, showing the spatulate-mucronate apex D Glandular hair from the cincinnus axis and floral tube E Dissected perianth lobes, showing the 5+1 arrangement F Lateral stamen G Uniseriate hair from the lateral stamen H Central stamen I Gynoecium, showing the glabrous style and unevenly trilobate stigma. Illustration by M.O.O. Pellegrini, based on the paratype (Smith & Reitz 9103, US).