Fig. 1

Floral morphology of successive Nitraria tangutorum flower developmental stages. a S1: stage 1, the petals form a tightly enclosing structure, b S2: stage 2, the petals begin to expand and split, c S3: stage 3, the androecium surrounds the gynoecium, d S4: stage 4, pollination was successful and small fruit has appeared. Scale bar =1 mm (a-b) or 2 mm (c-d)