Allium triquetrum

Morphological description

Perennial herbaceous plant belonging to the family Amaryllidaceae, it has a scapose habit and reaches a maximum height of about 30 cm. The root system consists of white, oblong, and compact bulbs, with a thickness that can reach up to 1.5 cm. The stem, or scape, is particularly characteristic for its triangular cross-section, with three pointed wings, from which the specific name derives. At the base of the stem, 2-3 ribbon-shaped leaves are inserted, flattened and keeled on the lower surface, longer than the scape itself, with a width ranging between 3 and 12 mm. The upper leaves are shorter and curved.

The flowers are grouped in loose and asymmetric umbels, with a variable number from 3 to 15 per inflorescence, and are borne on peduncles 1 to 4 cm long. At the base of the umbel there is a two-valved spathe of greenish color which, during flowering, splits and opens assuming a white coloration. The flowers, hermaphroditic and fragrant, have a campanulate shape and can reach a length of about 18 mm. They are composed of six pointed petaloid tepals of white color with a characteristic median green stripe. The stamens, also six in number, are contained inside the perigonium and reach about half its length. The ovary is superior. The fruit is a loculicidal capsule that opens to release the seeds.

Habitat and distribution

This species is typical of humid and shady environments, such as woods, hedges, edges, and road embankments. It grows on generally fresh and well-drained soils, at an altitudinal range from 0 up to about 600 meters above sea level. Distributed in the western Mediterranean basin, its range includes Liguria, the coasts of Spain and Algeria. In Italy it is mainly found in coastal regions with a Mediterranean climate, typically within the area called “dell’Olivo,” where the environment favors its growth.

Flowering period

Flowering mainly extends from November to April, with some variations linked to local climatic and geographic conditions. During this period, the pendulous white flower umbels can be observed in their typical unidirectional arrangement.

Ecology and pollination

The fragrant flowers and campanulate structure favor the attraction of pollinating insects, such as bees and other pollinators that facilitate sexual reproduction. The arrangement of flowers in asymmetric umbels and the presence of spathes that open at the time of flowering are functional adaptations to increase the effectiveness of pollination. Seed dispersal occurs through the loculicidal capsule that opens spontaneously at maturity, favoring the release and distribution of seeds in the surrounding substrate.

Curiosities and traditional uses

Allium triquetrum is an edible and medicinal species, known since antiquity for its beneficial properties. Like most Allium, it contains allicin, a compound with hypotensive, antibiotic, disinfectant, and hypoglycemic properties, and recent studies highlight its positive effects on cardiovascular diseases. Traditionally, both the scape and the small bulbs were consumed raw as salad or used to flavor legume soups.

Historically, garlic was highly valued already 5000 years ago by the Egyptians, who considered it precious enough to use it as a commodity for purchasing slaves. It was also an integral part of the diet of workers engaged in the construction of the Cheops pyramid, to increase their physical resistance.

In the Middle Ages and the Renaissance, Allium triquetrum was attributed numerous therapeutic virtues: it was believed to be effective in combating intestinal worms, stimulating diuresis, treating viper bites, helping hydropic patients, clarifying the voice, relieving persistent cough, eliminating lice, resolving bruises, and promoting the regrowth of lost hair. These indications, although belonging to popular tradition, testify to the long history of medicinal use of the plant.

Moreover, Allium triquetrum is used in repellent preparations, exploiting its aromatic and antibiotic properties.

Etymology

The genus name, Allium, derives from classical Latin and historically identifies plants commonly known as garlic. The etymological origin is debated and could derive from Indo-European roots related to terms for bitter herbs or from ancient linguistic loans, such as Greek or Akkadian. One possible interpretation is linked to the image of the bulb divided into “wings,” i.e., cloves.

The specific name triquetrum refers to the characteristic triangular shape of the stem, which has three protruding points.

The common Italian name “aglio con stelo trigono” directly recalls this peculiar shape of the stem, which constitutes the distinctive trait of the species.

Sources

• Acta Plantarum - Flora delle regioni italiane (actaplantarum.org)
• Acta Plantarum - Flora delle regioni italiane (scheda di Giuliano Salvai)