Vibrotome sections of I. lacunosa seeds showing seed coat away from hilar and bulge area (A); seed coat under hilum (B); bulge and micropyle area (C); hilum fissure (D); bulges detached (E); hilum–bulge area (F); bulge–hilum margin (G); and bulge–adjacent seed coat margin (H). BP, Bulge; [BP], detached bulge; CP, counter palisade; EC, endodermal cells; EP, epidermal cells; ES, elongated and compacted sclereid cells under bulge; HP, hilum pad; HS, hilar fissure; L, light line; MP, micropylar region; PC, palisade cells; QS, square-shaped, less compacted sclereids in seed coat away from the hilar and bulge area; QSH, square-shaped, less compacted sclereids in hilum pad; SC, sclereid cells; SL, slit; [SL], place where slit occurs.