PHYLLOTAXIS THEORIES AND TEPAL‐STAMEN SUPERPOSITION IN BASELLA RUBRA

Instead of alternating as is typical for the majority of flowering plants, the five stamens of Basella rubra are superposed to the five tepals. The first two tepals toward the abaxial side are initiated first, followed by the two tepals toward the adaxial side and the abaxial tepal that may be lagging behind. Stamen inception mirrors that of the petals, i.e., the two stamens toward the abaxial side are initiated first, followed by those toward the adaxial side and the abaxial one that may be lagging behind. Existing phyllotaxis theories do not seem to fully explain this pattern of petal‐stamen superposition. Apart from the Basellaceae, superposition between perianth members and stamens or stamen fascicles occurs in about 13% of all families of flowering plants, although in some of them it is restricted to only a few members. Other floral patterns that also resist explanation in terms of existing phyllotaxis theories are briefly discussed.