Image acquisition
For image acquisition, diaspores were arranged on the flat scanner avoiding any contact or overlap. The number of sampled diaspores varied for each taxon according to their availability in the seed collection (Figure 3). We sampled all available material that met sample preparation standards for up to 30 diaspores. In cases where the number of available diaspores exceeded 30, we sampled seeds to cover an area of up to 200 cm2. The flatbed scanner was covered with a wooden frame 10 mm thick with a royal blue background (Figure 4). Images were acquired with a flatbed scanner (HP Scanjet G4010) at a resolution of 1,200 DPI to well-represent small seeds and fine appendages. All automatic correction functions associated with the scanner software were disabled to ensure that the RGB values of the samples were not manipulated. The resulting images were saved in the Joint Photographic Experts Group (JPEG) format with no compression.