Wall Rue: Applications, Treatments, Health Benefits

Wall rue (Asplenium ruta-muraria) is an evergreen fern of the striped fern family that prefers to grow in wall and rock crevices. It is said to be a small medicinal plant with a small effect. Nevertheless, it is a multi-talent, as it supports all organs. Despite these positive attributes, it no longer plays a role in modern herbal medicine.

Occurrence and cultivation of wall rue

An infusion of tea from the dried leaves of the plant helps as a mouthwash against minor injuries and inflammation of the oral cavity. In folk medicine, the striped fern still has some applications. Wall rue is also known by the English name wall rue, as well as by the vernacular names wall striped fern, stone rue, and stoanneid herb. The perennial fern is native to all temperate hemispheres of the Northern Hemisphere and grows very slowly, it can reach a height of 15 centimeters. The plant is a cultural follower, as it prefers to grow in mortar joints and crevices of old walls and penetrates into inner cities. The plant chooses these locations because the walls of old masonry in their original state have hollow and moist cracks and joints, which the wall rue needs to grow. It can also withstand periods of drought. Its natural habitat is mountains and low mountain ranges, where it tolerates both acidic and calcareous rock. However, it prefers nutrient-rich limestone. In its natural habitat, it occurs only as a companion to other crevice plants. Outside these natural habitats, it is given the character of a separate plant species under the scientific name Asplenietum trichomano-rutae-murariae – wall-rue. The thickened rhizome and leaf glands bridge the dry periods and keep the rosette plant from drying out. The leaves are three to four pinnate and show an irregular triangular to oval outline. The pinnae are diamond-shaped, incised or notched at the front, and wedge-shaped at the base. They grow two to three millimeters long. The petioles and leaf blade are green. When the sori (accumulation of sporangia) have reached the mature stage, they cover the entire underside of the pinnae, which then turn brown. The fern plant now looks uniformly green from above and brown from below. In ferns, fertilization occurs by a drop of water on the underside of the prothallium, and the eggs chemically attract the spermatozoids. The pregerms are lentil-sized and grow in moist niches. Following fertilization, the sporophytes develop. These serve for reproduction and photosynthesis. Sporulation occurs throughout the year. The sporangia are arranged in the form of long strips along the vascular bundles on the underside of the fronds. They are covered by a transparent indusium (veil on ferns as a thin ligule). The sporangia are self-seeders with cohesion mechanism. Wind disperses the spores as granules fly. Between August and November the spores ripen on the leaves. Those who wish to use wall rue as a medicinal plant should collect the self-seeded wild specimens, as cultivation is quite difficult. However, its use is recommended only if there is sufficient knowledge of the plant, due to its slightly toxic effect.

Effect and application

The natural ingredients of stone rod are tannins and tannins. Since many of the plant’s own ingredients can unleash strong side effects when unprocessed, a cautious and exclusively diluted dosage is recommended. In folk medicine, striped fern was mainly used as an expectorant, for lung, liver, spleen and eye ailments and in astringency. Its medicinal properties are astringent, antipyretic, detoxifying, blood purifying, ophthalmic, menstrual, diuretic, stonolytic and expectorant. A use is induced in eye diseases, menstrual cramps, swellings and rickets. An infusion of tea from the dried leaves of the plant helps as a mouthwash against minor injuries and inflammation of the oral cavity. Cooked in wine, fern is said to stimulate hair growth as a hair rinse. Fern leaves and roots preserved in chamomile oil make a tincture for rubbing against swellings, muscle cramps and varicose veins. In modern medicine, the fern plant is no longer used.Interested amateur healers will not find much about this rosette-shaped fern plant in this regard. The references of herbal medicine are mainly exhausted in the preparation of teas and historical backgrounds from folk medicine. Mainly experienced herbalists of the rural and traditional mountain areas of Bavaria and Austria still use this cultural successor as herbal mixture, herbal tea or as tincture for rubbing. Thus, the stone rod plays a role mainly in garden culture together with other fern species as an ornamental plant.

Health significance, treatment and prevention.

Like all ferns, stone rue is slightly poisonous. The leaves of the plant, which can be collected and used throughout the year, are difficult to dose. For this reason, self-responsible, medical self-experimentation is discouraged. Contraindications are pregnancy and lactation. Complaints that may occur in connection with the use of striped fern are typical symptoms of poisoning, such as nausea, vomiting, fatigue and dizziness. Since wall rue no longer plays a role in modern medicine, it is not used in the field of homeopathy, unlike many other medicinal herbs. For this reason, pharmacies and alternative practitioners do not sell products with its components in the form of globules, tablets or ointments. Also, unlike many other popular herbs such as St. John’s wort or nettles, the fern plant is not for sale as a herbal tea. However, rock rue is still popular with some people for eye ailments. In the past, eye drops were made from the dried plant extract to treat eye inflammation. Nowadays, however, such use is discouraged because of a possible risk of infection.