umbel

An umbel is a type of inflorescence in which a cluster of flowers shares a common point on the flowering stem; each flower is borne on its own short stalk, or pedicel, and all pedicels radiate outward to resemble an umbrella. The term comes from Latin umbella, a diminutive of umbra, shade. Umbels are especially characteristic of the Apiaceae (the Umbelliferae).

There are simple umbels, where all pedicels originate from a single point on the main axis, and compound umbels, where the main stalk bears rays that end in one or more secondary umbels (umbellules). The overall inflorescence can be flat-topped or slightly domed.

Flowers in umbels are usually small, actinomorphic, and arranged densely; colors are typically white or yellow, sometimes greenish. They often bloom in spring or summer and attract a variety of pollinators. Heads of umbels may be accompanied by bracts and running from the base to the tip of the inflorescence.

Common examples include Daucus carota (carrot), Foeniculum vulgare (fennel), Anethum graveolens (dill), Petroselinum crispum (parsley), Apium graveolens (celery), and Coriandrum sativum (coriander). Larger or highly conspicuous umbels occur in Heracleum mantegazzianum (giant hogweed) and Conium maculatum (poison hemlock).

In botany, the umbel is a key identifying feature within the Apiaceae and is frequently used to describe and classify herbaceous plants and some trees with umbrella-like flower clusters.