Marcgraviaceae/Tetrameristaceae/Balsaminaceae. Histology; mucilage cells, raphides and stone cells in floral organs. (a–d) Schwartzia brasiliensis (Marcgraviaceae). (a) Petal, mucilage cell with non-thickened cell wall. (b) Gynoecium, cells with uniformly thickened cell walls containing raphides. (c) Petal, group of stone cells with thickened, layered cell walls. (d) Sepal, cell with uniformly thickened cell wall and mucilaginous cell centre. (e) Pentamerista neotropica (Tetrameristaceae); petal, cell with uniformly thickened cell wall containing both mucilage and raphides. (f–i) Pelliciera rhizophorae (Tetrameristaceae). (f) Sepal, mucilage cell with non-thickened cell wall. (g) Sepal, mucilage cell with non-thickened cell wall containing raphides. (h) Sepal, cell with uniformly thickened cell wall and mucilaginous cell centre. (i) Gynoecium, stone cell with thickened, layered cell wall. (j) Impatiens parviflora (Balsaminaceae); gynoecium, mucilaginous cells with both non-thickened (on the left) and uniformly thickened cells walls containing raphides. Scale bars: (a,c,e,f–i) = 50 µm; (b,d,j) = 10 µm.