A catkin arrangement of flowers.
A corymb arrangement of flowers.
This Lily of the Valley forms flower clusters, or racemes.
A head is a flower cluster with a short body, and without pedicles to the blossoms.
A simple panicle, the branches only once branched.
A raceme arrangement of flowers.
A spathe is a bract or leaf enwrapping a spike or cluster or blossoms.
A spike arrangement of flowers.
An umbel arrangement of flowers.
Racemes clustered in racemes, making a compound raceme, or umbel as in this Caraway.