FIGURE 3 in Plant structure ontology: How should we label plant structures with doubtful or mixed identities? *

FIGURE 3. Ricinus communis (Euphorbiaceae). Development of complex androecial units inside the calyx of male flowers (calyx removed in Figs. A–E). A. Young male flower bud. Triangular floral apex starting to form primary primordia. Scale bar = 150 µm. B. Next floral developmental stage, showing ca. 11 primary primordia. Scale bar = 80 µm. C, D. Two consecutive stages of androecium development. The primary primordia divide to form secondary and tertiary primordia. Scale bars = 150 µm. E. Young branching stamens seen from the side. Scale bar = 400 µm. F. Portion of mature branched stamen showing primary, secondary and tertiary branches. Note anthers with thecae separated by elongated connective appendages at ends of the distal branches. Scale bar = 1 mm. G. Mature male flower with calyx divided into 5 reflexed lobes. Several branched stamens are shown: the central ones with long stalks, the peripheral ones with short stalks. Scale bar = 3 mm.