Clonal and sexual reproduction of Wolffia plants, the smallest angiosperm. A, Plants of Wolffia globosa (Roxb.) Hartog in clonal reproduction. B, Close-up view of W. globosa vegetative fronds showing mother frond (MF) and daughter fronds (DF). C, Close-up view of W. globosa fronds showing maturation of minute protogynous flowers. D, Several flowering fronds under natural condition. Photographed by Jun-Xia YUAN and Qing HUANG. See YUAN et al., pp. 509–517 in this issue.