Fig. 1

Observation on the petal cells of sweet osmanthus flower from S1 to S6 with SEM and TEM. a Observation on adaxial petal epidermal cells with SEM. White bar 50 μm; b Observation on abaxial petal epidermal cells with SEM. White bar 50 μm; c Observation on adaxial petal epidermal cells with TEM. White bar 5 μm. S1), the outer bud scales unfurled and the inner bud scales still furled; S2, the bud became globular-shaped and the inside bracts covering the inflorescence was visible; S3, the inflorescence burst through bracts and the florets closely crowded; S4, initial flowering stage; S5, full flowering stage; S6, pollen-scattered stage