umbellet

/ˈʌmbəˌlɛt/
noun
  1. A small or secondary umbel, especially one forming part of a compound umbel.
    • Each umbellet of the fennel plant contains dozens of tiny yellow flowers.
    • The gardener examined the umbellet closely to see if the seeds were forming.
    • In a compound umbel, the main stalk branches into several umbellets.