Stellaria media

Morphological description

Annual or biennial herbaceous plant, common chickweed presents prostrate or prostrate-ascending stems, branched from the base, generally 10 to 40 cm long, sometimes up to 50 cm. The stem is quadrangular in section, thin, green or with reddish shades, characterized by a single line of alternating hairs along each internode, which can sometimes be glabrous. At the nodes, the stem can produce roots, contributing to its widely spreading habit on the ground.

The leaves are opposite, ovate or ovate-rounded in shape, with entire margins and acute or acuminate apex. The lower leaves are petiolate with petioles as long as the leaf blade, while the upper ones are larger and sessile. The leaf texture is herbaceous, generally glabrous, with some slight ciliations at the base. The floral bracts are herbaceous, progressively smaller.

The flowers are small, numerous, gathered in rather loose terminal dichasial cymes. Each flower is borne on an erect pedicel 3-40 mm long, which elongates during fruiting to 4-6 times the length of the calyx and bends downward, often covered with spreading hairs.

The calyx consists of five lanceolate, obtuse sepals, 3-5(6) mm long, generally hairy outside and with narrow membranous margins. The petals are white, deeply bifid, about one-third to two-thirds the length of the sepals, but can sometimes be absent or reduced. The stamens are 3-5, with thin white filaments and rounded anthers, violet-reddish in color.

The ovary is unilocular, greenish-green, with three erect white styles, which tend to curve in later stages. The fruit is a pyriform or ovoid capsule, 2.5-5 mm long, opening apically in six valves, slightly protruding beyond the persistent calyx. The seeds are small, reniform, reddish-brown, covered with rounded tubercles of flat or convex shape.

The root system consists of a thin, shallow taproot.

Habitat and distribution

Common chickweed is a cosmopolitan species, widely distributed throughout the Italian territory and the Mediterranean basin, without significant gaps in its distribution. It mainly grows in anthropized environments, as a weed of cultivated fields, vegetable gardens, gardens, roadsides, dumps, and wet places. The species adapts to different soil types, preferring well-worked or disturbed soils, although it can tolerate variable conditions.

In Italy, it is found from the plains up to altitudes of 1600-2500 m a.s.l., showing remarkable ecological plasticity. It is frequent both in hilly and foothill areas and in high mountains, where it exploits open and sunny or partially shaded environments.

Flowering period

The flowering of common chickweed is very extended, potentially lasting from January to December in mild climate areas, with flowering peaks from spring to autumn. The presence of flowers almost throughout the year is favored by the plant’s ability to adapt to variable climatic conditions and its annual or biennial nature.

Ecology and pollination

The species reproduces through hermaphroditic flowers, predominantly autogamous but potentially pollinated by small pollinating insects attracted by the white flowers. The flower structure, with deeply bifid petals and colored anthers, favors the attraction of small pollinating insects.

Seed dispersal mainly occurs by falling near the mother plant, but also through animals that can accidentally transport them. The seeds are also appreciated by numerous granivorous bird species, which indirectly contribute to the plant’s spread.

Curiosities and traditional uses

Common chickweed is traditionally known for its medicinal properties and its use as an edible wild plant. It contains tannins, mineral salts, saponins, and vitamins that confer diuretic, laxative, diaphoretic, and expectorant properties. It is also used externally as a soothing and refreshing agent for eczema, itching, and ulcers.

In cooking, the young and tender parts of the plant are used in soups, fillings, and side dishes, but consumption should be limited to small quantities due to the saponin content, which in excess can be toxic. The popular name "centocchio" probably derives from the ease with which the plant grows everywhere, almost like “a hundred eyes” watching the surrounding environment.

Birds particularly like the seeds, from which various vernacular names derive such as “erba passerina” or “mordigallina”.

Etymology

The scientific name derives from the Latin stellaria, meaning “pertaining to the star”, recalling the star-shaped form of the flowers when fully open. The Italian name “centocchio” alludes to its abundance and widespread presence, as if the plant had “a hundred eyes” on the ground.

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)