Apium graveolens Celery - Apiaceae

Inflorescence Type: compound umbel (=umbel of umbels)
Note peduncle (below) and rays, the latter terminating in simple umbel units

Foeniculum vulgare Fennel - Apiaceae

Inflorescence Type: compound umbel (=umbel of umbels)
Note rays terminating in simple umbel units (the flowers pedicellate)