Campanula rapunculus

Morphological description

Biennial herbaceous plant reaching a height between 30 and 100 cm, with an erect habit and thin, angular stem, generally glabrous or with slight scattered pubescence, often branched in the upper part. The base is provided with a taproot, tuberous and fleshy, fusiform in shape, whitish, up to about 10 cm long, similar to a small turnip.

The basal leaves are arranged in a rosette and are oblanceolate or oblong-obovate in shape, with dentate or crenate-dentate margins and light green surface, often wavy. These leaves have a petiole and develop mainly in autumn and spring. The cauline leaves, instead, are very reduced, lanceolate or linear, sessile, alternate and sparse, up to 1.5-2 cm long, with simpler margins compared to the basal ones.

The flowers are gathered in panicles or narrow and elongated clusters, with pedicellate axillary flowers arranged more or less erect. The calyx is glabrous, formed by five linear teeth, about two thirds the length of the corolla, often patent or turned backward. The corolla is campanulate, gamopetalous, 1-2 cm long (up to 2.5 cm according to some sources), with color varying from pale blue-lilac to lilac, rarely white or pinkish-violet, with five acute lobes folded outward, reaching about one third of the total length of the corolla. The dimensions of the corolla tend to be longer than wide, with a tube length equal to about two thirds of the flower. The style is simple and hairy, while the stamens are five, free with swollen filaments at the base.

The fruit is a dehiscent capsule, erect and glabrous, containing numerous small seeds.

Habitat and distribution

Species widely distributed in the paleotemperate area, found in many regions of Europe, Western Asia and North Africa. In Italy it is present throughout the territory, preferring environments with calcareous and well-drained soils. It commonly grows in uncultivated places, roadsides, fields, dry meadows, olive groves and coppices, up to an altitude of about 1500 m a.s.l.

It prefers sunny or partially shaded exposures, typical of open woodland environments, clearings, forest edges and dry grasslands. Its presence is common in Mediterranean and temperate regions, where it adapts well to poor and dry soil conditions.

Flowering period

The flowering generally extends from May to August, with possible variations depending on altitude and latitude. In more temperate or mountainous climates, flowering may start later or be shorter, while in warmer and Mediterranean areas it can begin already in late spring.

Ecology and pollination

The plant is mainly pollinated by pollinating insects attracted by the blue-lilac color of the flowers, such as bees, bumblebees and other hymenopterans. The structure of the corolla, with its open lobes and campanulate shape, facilitates access to nectar and pollen. The presence of a well-developed and toothed calyx helps protect the flowers during development.

The seeds contained in the capsule are small and light, favoring dispersal mainly by falling (barochory), but they can also be transported by insects or small animals that facilitate their spread in the surrounding territory.

Curiosities and traditional uses

The root of this species is edible and appreciated in cooking for its sweetish taste, due to the presence of inulin, a carbohydrate that does not contain starch and which, when broken down, produces levulose instead of glucose. This makes the consumption of the root suitable also for diabetics. The roots are consumed raw, often in salads, while the basal leaves, with a bitter but pleasant taste, are used to flavor soups, broths and savory pies.

From a medicinal point of view, the leaves were used in external applications to combat warts, while the infusion of the flowers was employed as a mouthwash for gargling. The plant therefore has a traditional officinal value, although such uses should be considered for informational purposes only.

The German name Rapunzel-Glockenblume is known thanks to the Brothers Grimm fairy tale "Rampion Bellflower", in which the protagonist is associated with this plant, highlighting its cultural as well as botanical importance.

Etymology

The generic name "Campanula" derives from the bell shape of the flowers typical of the genus. The specific epithet "rapunculus" means "small turnip" in Latin, referring to the shape of the tuberous root, similar to that of a turnip. The common Italian name "Rampion Bellflower" recalls this characteristic, emphasizing the edible root and the popular tradition linked to the plant.

Sources

• Prof. S. Pignatti, "Flora d'Italia"
• Acta Plantarum - Flora delle regioni italiane (scheda di Giuliano Salvai)
• Tela Botanica / H. Coste, "Flore descriptive et illustrée de la France"
• World Flora Online (WFO)