The World of Campanula: Biology, Taxonomy, and Horticulture

Campanula, commonly known as bellflower, is the type genus of the Campanulaceae family. The name “Campanula” originates from Latin, meaning “little bell,” which refers to the characteristic bell-shaped flowers of these plants.

This genus includes more than 500 species along with numerous subspecies, primarily distributed across temperate and subtropical regions of the Northern Hemisphere. The greatest diversity is found in areas such as the Mediterranean basin, the Balkans, the Caucasus, and parts of Western Asia. Some species are also native to mountainous tropical regions in Africa and Asia.

Campanula species exhibit a wide range of life cycles, including annuals, biennials, and perennials. Their size varies significantly, from small alpine or arctic plants only about 5 cm tall to taller species that can reach up to 2 meters in height in meadows and woodlands.

Morphology

Leaves are arranged alternately along the stem and often vary in shape depending on their position. Basal leaves tend to be broader and larger, while those higher on the stem are usually narrower. Leaf margins may be smooth or toothed, and both forms can occur on the same plant. Many species contain a milky latex in their stems and leaves.

Flowers are typically borne in panicles, although solitary blooms can also occur. Each flower consists of five fused petals forming a bell-like corolla, usually measuring between 2 and 5 cm or more in length. The most common colors are blue and purple, but white and pink varieties are also found. Beneath the corolla lies the calyx, composed of five sepals. In some species, small appendages appear between the sepals, which are useful for distinguishing closely related taxa.

The fruit is a capsule that contains numerous small seeds.

Ecological Relationships

Campanula plants serve as host species for the larvae of various Lepidoptera insects. These include species such as the common pug moth, the dotted moth, the mouse moth, and others, which rely on bellflowers as a food source during their development.

Cultivation and Uses

Several species are especially well known in horticulture:

Campanula rotundifolia is referred to as “harebell” in England, while in Scotland and Ireland it is often called “bluebell,” though it is not related to true bluebells

Campanula medium, native to southern Europe, is widely cultivated as an ornamental plant and is commonly known as “Canterbury bells”

In addition to wild species found in northern Europe, many cultivated varieties exist. Notable cultivars such as ‘Misty Dawn’ and ‘Kent Belle’ have received the Award of Garden Merit from the Royal Horticultural Society.

Campanula rapunculus, commonly known as rampion, is a biennial plant historically grown in Europe as a vegetable. Its leaves can be eaten similarly to spinach, and its roots resemble radishes. This plant is famously associated with the story of Rapunzel from the Brothers Grimm, although it should not be confused with Valerianella locusta, which is also sometimes called rampion.

In the United Kingdom, national collections of Campanula are maintained at Burton Agnes Hall in East Yorkshire and at Langham Hall in Suffolk.

Taxonomic Notes

Within different classification systems, some members of the Campanulaceae family are sometimes included in Campanula or treated as separate genera, such as Azorina, Campanulastrum, Canarina, Edraianthus, Musschia, Ostrowskia, and Platycodon.

Additionally, certain groups that were once classified within Campanula—such as Annaea, Gadellia, and Theodorovia—have been reassigned in some taxonomic treatments. Other names like Hemisphaera and Neocodon have also been used historically for subdivisions within the genus.