The umbrella is an inflorescence typical of Apiaceae or Umbelliferae; this can be simple or composed.
The umbrella is a racemose inflorescence (a cluster) formed by flowers with pedicels (rays) that all start from the same point and reach the same height.
The compound umbrella is similar to the simple one, but with the rays that end with other small umbrellas (umbrella) on which the flowers are inserted.
The characteristic of the umbrella is that, often, this is provided at the base of a casing formed of bracts. In it the flowers are small and symmetrical pentamera: you have 5 petals and 5 stamens, with in the center an ovary inferior to two carpels. The sepals are absent or, in some cases, very reduced due to the fact that the glass is almost completely welded to the ovary.
In the umbrella, in some cases, the peripheral flowers are irregular; in this case the external petals are clearly larger, and contribute to making the umbrella the so-called “similar flower”. The ovary carries two styles that widen at the base in a nectariferous disk.