Umbel

Type of inflorescence

Conioselinum pacificum

An umbel is a type of inflorescence that is characteristic of the Apiaceae family, although it can be found in other plant families as well. In an umbel, the individual flower stalks, known as pedicels, arise from a common point, much like the ribs of an umbrella. This structure can be simple or compound, with the latter having secondary umbels, or umbellets, branching off the main stalks.

Structure

Umbels can vary in size and complexity. A simple umbel consists of a single layer of pedicels that radiate from a central point. In contrast, a compound umbel has multiple layers, with each primary pedicel supporting a secondary umbel. This arrangement is particularly common in the Apiaceae family, which includes well-known plants such as Daucus carota (carrot) and Conioselinum pacificum.

Daucus carota

The structure of an umbel allows for efficient pollination, as the flowers are presented in a flat or slightly rounded cluster, making them easily accessible to pollinators such as bees and butterflies. The uniformity of the flower arrangement also aids in the dispersal of seeds.

Examples

Several plant species exhibit umbel inflorescences. Some notable examples include:

• Daucus carota, commonly known as Queen Anne's lace, is a wild carrot species with a characteristic white umbel.
• Conioselinum pacificum, known as Pacific hemlock-parsley, features compound umbels typical of the Apiaceae family.
• Fatsia japonica, although not in the Apiaceae family, displays umbels in its flowering structure.
• Primula veris, or cowslip, is another example of a plant with umbel-like inflorescences.
• Pelargonium zonale, a type of geranium, also exhibits umbel formations.

Fatsia japonica

Ecological Significance

Umbels play a significant role in the ecology of their environments. The open and accessible structure of the umbel makes it an attractive target for a variety of pollinators. This can lead to increased genetic diversity and successful reproduction for the plants. Additionally, the dense clustering of flowers can provide a visual signal to pollinators from a distance.

Related pages

• Inflorescence
• Apiaceae
• Pollination