All Pilea species are monoecious: staminate and pistillate flowers occur on same plant, even mixed in same inflorescence. To avoid self-pollination, they ripen at different times. By the time achenes are maturing, as here, staminate flowers are gone. They differ in the number of tepals: 4 instead of 3. One such four-tepal remnant of staminate flower is present here at lower left.