Moehringia muscosa

Morphological description

A small perennial herbaceous plant, Moehringia muscosa presents a tufted habit and prostrate or ascending-branched stems, forming loose and fragile clumps. The height generally varies between 5 and 20 cm, with greenish, glabrous stems characteristically thickened at the nodes. These stems branch from the base and are often slightly ascending, rarely completely erect.

The leaves are opposite, thin, from linear to filiform, with a length that can exceed 3 cm (commonly 20-30 mm, rarely up to 50 mm) and very reduced width, never spatulate towards the apex. The texture is herbaceous and the surface glabrous. The leaf venation is generally single, sometimes with three weak nerves.

The flowers are small, with an overall diameter of about 6-8 mm. They are generally 4-merous, rarely 5 or more petals, arranged in terminal dicyclic inflorescences, composed of 3-6 flowers on thin peduncles up to 12 mm long, which tend to diverge after flowering. The petals are white, obovate in shape, about 7 mm long, i.e. about 1.5 times longer than the sepals, thin and lacking a distinct claw. The sepals are narrowly lanceolate, acute, about 3 mm long, with a single vein, with a wide and scarious margin. The plant has 8 stamens and 2 styles.

The fruit is a denticidal capsule, about as long as the calyx, which at maturity releases reniform, brownish, smooth and shiny seeds, 1.2 to 1.5 mm long, characterized by a narrow slit incision. The strophiole is conical, formed by large and short cells, and in some cases fused into a plate with an entire and thickened margin.

The root system is not described in detail in the sources, but like many mountain perennial herbs it is presumably fibrous and shallow, suitable for rocky or mossy soils.

Habitat and distribution

This species is typical of mountain and submontane environments, with a preference for calcareous substrates. It grows mainly in humid areas, on walls, soil, mosses, shady woods and cliffs, often in rocky and shaded places up to 2,400 meters altitude.

In Italy it is mainly reported in the Alps and the northern and central Apennines, with some stations also in the Pollino. Some occurrences have been reported, albeit with reservation, also in Capri and on Etna. The distribution extends within the European orophyte context, with greater concentration in the southern mountain chains and the Alpine margin.

The preferred environment is calcareous, generally shaded and humid exposure, often in microsites covered by moss, from which the specific name also derives.

Flowering period

Flowering extends from May to August, with possible variability related to altitude and latitude. In the Alpine reliefs the flowering season is mainly concentrated between June and July, while in more southern areas or at lower altitudes it can start as early as May and continue until late summer.

Ecology and pollination

Moehringia muscosa is a species mainly pollinated by pollinating insects, although no detailed data are available on the species involved. The flower structure, with fairly conspicuous white petals and numerous stamens, favors the attraction of pollinators. The presence of terminal inflorescences with multiple flowers facilitates insect visits.

Seed dispersal occurs through denticidal capsules which, at maturity, open releasing small and light seeds, probably dispersed mainly by wind and water. The conical and prominent strophiole could play a role in facilitating dispersal, although no particular strategies of anemochory or zoochory are known.

The plant is a tufted hemicryptophyte, with perennial buds at ground level, which allows it to survive cold winters and even difficult mountain conditions.

Curiosities and traditional uses

No traditions of specific food or medicinal use are known for this species. The Italian common name "erba paglina" probably refers to the thin and filiform appearance of the leaves, which resemble fine straw or thin threads.

There are no relevant folkloric or ethnobotanical references in the specialist literature, probably due to the modest distribution and habitat restricted to mountain areas.

Etymology

The genus name Moehringia is dedicated to Paul Heinrich Gerhard Moehring (1710-1792), a German botanist who contributed to the knowledge of European plants.

The specific epithet muscosa derives from the Latin "muscus", meaning moss, alluding to the ecological preference of the plant for environments covered by moss or similar in appearance and habitat to moss.

The Italian common name "erba paglina" probably refers to the thin and filiform shape of the leaves, which recall fine straw.

Sources

• Prof. S. Pignatti, "Flora d'Italia"
• Acta Plantarum - Flora delle regioni italiane (scheda di Giuliano Salvai)
• World Flora Online (WFO)