Figure 3.—

Architecture of Petunia flowers. (A) Schematic of a Petunia flower showing the traditional division into tube and limb and the subdivision in domains D1, D2, and D3. (B) Cell-number and cell-length measures in a mature P. a. parodii flower (top) and a mature P. i. inflata flower (bottom). Right of the flowers is the division into D1, D2, D3, and the number of cells in each of the domains. Left of the flowers the length of the cells in a bottom-top (longitudinal) dimension is given. The length of flowers at the given developmental stage is given above the image in centimeters. Cell numbers and sizes were determined by low vacuum scanning electron microscopy. (C) As in B but for immature flowers. The length of flowers at the given developmental stage is given above the image in centimeters.