Fig. 4

Neutral red staining of Vanda Mimi Palmer flowers. A whole flower was immersed in 0.5% (w/v) aqueous neutral red for 10 min to 24 h (overnight), and then rinsed in tap water. Arrows indicate the stained areas. FRONT indicates the frontal view of the flower, BACK indicates the dorsal view of the flower, a and b indicate unstained flower as control, c and d stained for 10 min, e and f stained for 20 min, g and h stained for 30 min, i and j stained for 60 min, and k and l stained overnight