um·bel / ˈəmbəl/ • n. Bot. a flower cluster in which stalks of nearly equal length spring from a common center and form a flat or curved surface, characteristic of the parsley family.DERIVATIVES: um·bel·late / ˈəmbəlit; -ˌlāt; ˌəmˈbelit/ adj.

umbel An inflorescence in which all the pedicels arise at the apex of an axis. It is commonly compound, usually umbrella-shaped, and is characteristic of Umbelliferae .

umbel A type of racemose inflorescence in which stalked flowers arise from the same point on the flower axis, resembling the spokes of an umbrella. An involucre (cluster) of bracts may occur at the point where the stalks emerge. This arrangement is characteristic of the family Umbelliferae (Apiaceae; e.g. carrot, hogweed, parsley, parsnip), in which the inflorescence is usually a compound umbel.

umbel (bot.) inflorescence in which the flowers are borne upon nearly equal pedicels springing from a common centre. XVI. — F. †umbelle (mod. ombelle) or L. umbella sunshade, dim. of umbra shadow; see UMBRA.
So umbellifer XVIII, umbelliferous XVII.