Stamen structure of Humiriaceae. A Sacoglottis perryi stamen cluster of 2 types, ventral B Sacoglottis perryi stamen cluster of 2 types, dorsal C Sacoglottis perryi short-stamen anther with open stomium and pollen D Sacoglottis guianensis androecium with interstaminal staminodes (st), dorsal E Schistostemon macrophyllus stamen cluster of 3 types, ventral F Schistostemon macrophyllus stamen cluster of 3 types, dorsal G Schistostemon oblongifolius trifurcate filament tip, dorsal. Sources: A–C Tripp 2984 D Carvalho et al. 4396 E, F Maas et al. 6577 G Maas et al. 6804 (all US).