Glebionis coronaria

Morphological description

Annual herbaceous plant between 20 and 60 cm tall, with an erect and very branched habit. The stem is glabrous, that is hairless, and has an ascending and scapose appearance, with numerous branches that give the plant a dense and articulated structure. The emitted odor is intense and aromatic, a distinctive characteristic of the species.

The leaves are light green, sessile and bipinnatipartite, that is divided into lanceolate lobes which in turn are divided into smaller often toothed lobes. The lower leaves are larger and pinnatifid, while the upper ones tend to be narrower, oblong-lanceolate, sometimes clasping the stem and with toothed or entire margins.

The inflorescence consists of solitary capitula, varying in size from 30 to 50 mm in diameter, placed at the apex of the peduncles, which are thickened towards the end. The capitula have a crown of ligules (peripheral flowers) of intense yellow or yellow-white color, sometimes with partial orange shades. In the center there is a disc composed of numerous tubular florets of yellow-orange color. The scales of the involucre (modified calyx) are oval and often characterized by blackish edges.

The fruits are achenes 2-3 mm long; those derived from the outer (ray) flowers are distinctly trigonous with winged angles, while those of the disc are compressed, with four angles and a more pronounced posterior ridge. There are no pappus or specialized dispersal structures.

The root system is not described in detail in the sources, but since it is an annual species common in disturbed habitats, a taproot or fasciculate root can be presumed, suitable for rapid establishment in light and well-drained soils.

Habitat and distribution

It is a typically Mediterranean species, classified as Steno-Mediterranean, with distribution limited to the coastal areas of the Mediterranean basin, also known as an entity of the "Olive area". In Italy it grows mainly from the plain up to 600 meters of altitude, in anthropized environments such as cultivated fields, uncultivated lands, road edges, ruins and areas exposed to full sun.

It prefers well-drained and sunny soils, often disturbed by agricultural activity, where it behaves as a weed species. Its presence is frequent especially in regions with a Mediterranean climate, with extension also in the coastal areas of Southern Europe, North Africa and the Middle East.

Flowering period

Flowering occurs from April to August, with greater abundance during the summer months. The period may vary slightly depending on altitude and latitude, but in general the species is visible in flower from late spring until the end of summer.

Ecology and pollination

The species is pollinated by pollinating insects, attracted by the bright color of its flowers and the aromatic scent. The structure of the capitulum, with peripheral ligulate flowers and central tubular ones, is typical of Asteraceae and favors entomophilous pollination. No particular pollination strategies other than normal insect visits are reported.

Seed dispersal occurs mainly by natural fall of the achenes, which do not have winged or feathery structures for aerial transport. Probably human activity and the passage of animals also contribute to the spread of seeds in agricultural and uncultivated soils.

Curiosities and traditional uses

Known for a long time as a weed of Mediterranean crops, Glebionis coronaria is also appreciated for its food and medicinal uses. The leaves and young shoots are edible and used as vegetables or to flavor dishes, especially in Eastern cuisine, where it is widespread for its characteristic aroma and antioxidant properties.

Studies conducted in the Mediterranean, particularly at the CNR of Sassari, have shown that it is a good forage plant for grazing sheep, with positive effects on milk production. Furthermore, it is rich in essential oils with antifungal properties, useful during forage ensiling.

In traditional medicine it is known for its aromatic and antioxidant potentials, although pharmaceutical uses should be considered with caution and under specialist supervision. No particular folkloric or ritual references associated with the species are recorded.

Etymology

The specific name “coronaria” derives from the Latin corona (crown, wedding crown), referring to the "crown-like" arrangement of the ligulate flowers around the central disc. The Italian common name “Crowndaisy” recalls the color of the flowers and the resemblance to chrysanthemums, well-known ornamental flowers.

The current genus, Glebionis, has an etymology not clearly defined, while the former genus Chrysanthemum derives from the Greek chrysos (gold) and anthos (flower), meaning “golden flower”, precisely for the characteristic yellow color of the capitula.

Sources

• Acta Plantarum - Flora delle regioni italiane (actaplantarum.org)
• Acta Plantarum - Scheda di Mirna Medri
• Tela Botanica / H. Coste, Flore descriptive et illustrée de la France