possibly associated with the spread of phytoplasma which is affecting the flowers of the Dianella plants. See https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/yellows.html#:~:text=Phytoplasmas%20commonly%20cause%20distorted%2C%20dwarfed,%2C%20leaflike%20structures%2C%20called%20phyllody for general information about phytoplasmas.