Mimosa (Acacia dealbata)

While the yellow flowers Margarita is carrying are not identified in Part I of the novel, they would be instantly recognizable to Muscovites of the Soviet period as Mimosa, the first flowers to appear in the spring, imported from the South.

It is probably not insignificant that both the Mimosa and Margarita are only named in Part II.

Margarita's flowers are a symbol of misery; yellow is the color of the madhouse (state buildings were painted dark yellow, and "yellow house" means "madhouse"), as well as the color of betrayal--one should never give yellow flowers to a lover in Russia.