P. 'Mini Lamb' flowers have litmus paper like qualities. This is not surprising as the anthocyanin pigments are known to change their colour depending on the acidity or alkalinity of their environment. In contrast to the chlorophylls and carotenoids they are water soluble. The section of flower on the left has been dipped in a quite strong solution of mild alkali, bicarbonate of soda NaHCO3, pH 8.1. The section on the right has been dipped in lemon juice (citric acid) pH of 2.3. The middle flower has been recently picked and is just starting to dry out. It has not been treated in any way. The colours of the image, taken as one shot have not been altered. | 
Passiflora 'Mini Lamb' litmus paper!
