Convolvulus althaeoides

Morphological description

Perennial herbaceous plant, with a semi-climbing or prostrate habit, Convolvulus althaeoides has stems ranging from 30 to 60 cm long, with a woody base and twining, flexible herbaceous branches. The plant is completely rough due to spreading hairs, often brown in color, which give it a rough and bristly surface to the touch.

The leaves are petiolate, gray-green in color, with blade shape and size varying along the stem. The lower leaves are irregularly triangular, 15-25 mm wide and 20-30 mm long, with obtusely crenate or lobed margins. The upper leaves, positioned higher, are deeply divided into 5-9 unequal lobes: the central lobe is larger, lanceolate, and coarsely toothed. The leaf arrangement is alternate along the stem.

The flowers appear singly or in pairs in the axil of the smaller leaves, with peduncles 6-8 cm long that clearly exceed the size of the leaves themselves. At the base of the peduncles there are two linear bracteoles, located about one fifth from their tip. The calyx is formed by lanceolate and obtuse teeth, 7-10 mm long, with a velvety surface due to the presence of hairs. The corolla is conical, funnel-shaped, with a diameter of 2-3 (up to 4) cm and a length of 2-4 cm; the color is pink-lilac, more intense at the center, with darker shades towards the throat of the flower.

The fruit is a spherical capsule, sometimes slightly pointed, about 6 mm in diameter, generally containing 1-2 locules with four seeds (tetraspermic capsule). The plant also develops through a long rhizome that allows perennation and vegetative spread.

Habitat and distribution

Convolvulus althaeoides is a typically Mediterranean species, with a steno-Mediterranean distribution, limited to coasts and regions with a Mediterranean climate, including areas of central-southern and insular Italy. In Italy it grows in dry and open environments, preferring cliffs, clearings in the Mediterranean scrub, edges of roads and paths, up to an altitude of about 600 meters above sea level.

It prefers sunny exposures and poor, dry soils, often calcareous or rocky, typical of Mediterranean coastal and hilly areas. The presence of rhizomes gives the species a good ability to survive under drought conditions and in shallow soils.

Flowering period

Flowering mainly extends from April to June. In some Mediterranean areas, especially in warmer and coastal zones, flowering can begin as early as April and continue until June, with peak flowering in May. Flowering is relatively short and coincides with the milder and more humid spring months.

Ecology and pollination

Convolvulus althaeoides is pollinated by pollinating insects, attracted by the colorful flowers and their funnel-shaped form which facilitates access to nectar and pollen. The pink-lilac corolla, darker at the center, acts as a visual signal for pollinators, which mainly include bees and butterflies.

The plant exhibits a mixed reproductive strategy, being capable of reproducing both sexually, through seed production contained in the capsules, and vegetatively, through the rhizome which allows the formation of new plants even in the absence of pollination. Seed dispersal mainly occurs over short distances, favoring colonization of surrounding habitats.

Curiosities and traditional uses

Convolvulus althaeoides is a toxic medicinal species, traditionally used for its laxative and purgative properties. The leaves and roots, collected in spring, contain starch, gums, resins, sugars, salts, and saponins, which confer stronger laxative effects compared to other species of the genus Convolvulus.

In Mediterranean folk medicine, this plant has been used to treat fevers of hepatic-biliary origin, hepatic dropsy, and disorders of intestinal inertia due to liver insufficiency. The flowers have also been considered useful as febrifuges.

From a cultural and folkloric point of view, species of the genus Convolvulus have had a symbolic role in antiquity. Pliny the Elder and his contemporaries attributed ritual meanings to these plants, using them for sacrificial ornaments and funeral crowns. It was believed that the spirit of the Nymph Smilace, transformed into a plant for the love of the young Crocus, was imprisoned in these plants.

It should also be noted that medicinal use must be approached with caution, as the plant is toxic and the information provided is for informational purposes only.

Etymology

The genus name Convolvulus derives from the Latin convólvo, meaning "I entwine," referring to the twining and climbing stems typical of species in this genus.

The specific name althaeoides derives from the Greek term althaéa, which indicated a medicinal plant called Althea, and the suffix -oides meaning "similar to." It thus indicates a plant resembling Althea, whose Greek name altháino means "I heal," "I cure," emphasizing the medicinal value attributed to the species.

The Italian common name "vilucchio rosso" refers to the pink-reddish color of the flowers, a distinctive characteristic of the plant.

Sources

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