Erodium cicutarium

Morphological description

Annual or sometimes perennial herbaceous plant, with a bushy or scapose habit, generally 3 to 60 cm tall, but under favorable conditions it can also reach 60 cm. The stem is hairy with erect-patent hairs and often shows reddish shades; it can be reduced or subnull, with a length of 1-5 cm, and has a prostrate habit. The root system is taprooted.

The basal leaves are fully pinnately divided, 3-5 cm long and 1-2 cm wide, composed of 9-11 ovate segments, deeply incised for more than half of the blade, with a herbaceous texture and pubescent or rough surface. The leaves can be rosetted or cauline, alternate or opposite, with petioles up to 15 cm long. The stipules, located at the base of the petiole, are lanceolate-ovate, sometimes connate, with a ciliate margin and color ranging from pink to straw.

The flowers are hermaphroditic, actinomorphic, pentamerous and arranged in small umbels or cymes containing from 2 up to 10 flowers, supported by peduncles 1-2 cm long (from 1.5 to 6.5 cm according to the English source), which are erect during anthesis and bent during fruiting. The bracts at the base of the capitulum are ovate, acute, with ciliate margins, straw-colored or pink.

The calyx consists of five free sepals, 3-6 mm long, lanceolate-ovate, pubescent and with a short apical mucro. The petals are five, pink of varying intensity, sometimes with a dark spot at the base, 4 to 10 mm long and slightly longer than the sepals; their claw is ciliate and hairy. There are five fertile stamens alternating with five scale-like staminodes, all fused at the base.

The ovary is superior and bears styles fused into a characteristic elongated "beak" of 2.5-4 cm, which extends the fruit. The fruit is a schizocarp composed of five hirsute achenes, 4-7 mm long, with an apical pit and a more or less marked groove below it. At maturity, the achenes separate thanks to the hygroscopic movement of the style, which tears into spiral awns, facilitating seed dispersal.

The species shows high morphological variability depending on environmental conditions, with more vigorous plants and more abundant flowering on rich soils or in summer. The color and size of the petals can vary significantly.

Habitat and distribution

It is a subcosmopolitan species, present almost worldwide, with some gaps at continental or climatic levels. In Italy and the Mediterranean it commonly grows in anthropized and semi-natural habitats: uncultivated areas, road edges, dry meadows, vineyards and sandy soils. It prefers sunny exposures and well-drained soils, from sea level up to about 1800 meters altitude.

Its presence is frequent in thermophilic and hilly environments, also submontane, and it adapts to variable moisture conditions, from dry to moderately moist. In general, it is found in disturbed or open places, with loose and poor substrates, often in association with other pioneer species.

Flowering period

Flowering extends from February to November, with peaks in September-October, and can occur practically throughout the year in mild climate areas. The duration and maximum intensity of flowering vary depending on local climatic conditions and altitude.

Ecology and pollination

The flowers of this species, pink and pentamerous in structure, are visited by pollinating insects that favor pollination, although detailed data on the main pollinators are not available. The arrangement of flowers in scapose inflorescences facilitates insect access.

Seed dispersal occurs through a self-launching mechanism: the spiral beak of the fruit acts as a hygroscopic spring which, reacting to humidity changes, coils and uncoils, flinging the achenes far from the mother plant. Moreover, the spiral awns can adhere to animal fur, promoting epizoochorous dissemination.

Curiosities and traditional uses

This species is known for its medicinal properties and is used in traditional medicine. The whole plant, deprived of roots, collected in flowering, and the seeds contain tannins, ellagic acid, gallic acid and potassium salts. It is used as a diuretic, antihemorrhagic and uterine tone stimulant.

From a food perspective, the plant is edible and can be used in cooking as a wild vegetable. However, its use for therapeutic or food purposes should always be evaluated with caution and under specialist supervision.

The family Geraniaceae, to which it belongs, is characterized by names recalling the shape of fruits similar to the beak of wading birds: the genus Erodium derives from the Greek "erodios" (heron), Geranium from "geranòs" (crane) and Pelargonium from "pelargòs" (stork), highlighting the zoological inspiration in botanical nomenclature.

Etymology

The genus name Erodium derives from the Greek “erodios”, meaning "heron", referring to the elongated and pointed shape of the fruit similar to the beak of a heron. The specific name cicutarium refers to the similarity of the leaves to those of hemlock (genus Cicuta), due to their pinnatifid division.

The Italian common name "Becco di gru" also recalls the characteristic shape of the fruit, very elongated and pointed, similar to the beak of a crane.

Sources

• Acta Plantarum - Flora delle regioni italiane (actaplantarum.org)
• Acta Plantarum - Flora delle regioni italiane (scheda di Daniela Longo)
• World Flora Online (WFO)