FIGURE 4.

Revealing non-visible veins in corolla of flowers. (A) Wild-type of F. graciliflora flower mounted on a petri dish. (B) The absorption of a coloured liquid by the flower reveals its vascular system. As an example, the venation system of F. graciliflora is entirely revealed after the flower had spent several hours absorbing a solution made of blue dye. (C) F. graciliflora flowers that are relatively flat can be immersed into a solution of 70% ethanol to effectively destroy the cells responsible for pigmentation and reveal their venation network in high detail. Scale bar = 2 mm. (D,E) Clarity of pictures taken from non-2D flowers (Scabiosa columbaria, Dipsacaceae) can be improved via z-stacking or focus stacking that combines a set of pictures acquired at different focal points of the flower. (F) These images are subsequently compiled into a single and neat picture. All visible organs that could mask the corolla (e.g., stamen and carpel) should be discarded prior to any imaging. Scale bar = 5 mm.