Polypodium vulgare

Common name: Polypody of the Oak, Wall Fern, Brake Root, Rock Brake, Oak Fern

Plant Family: Polypodaceae

Habitat: Native to Europe, Africa and East Asia it is found in mainly northern or upland area. It grows on trees (both living and dead), in woodlands, and on old walls (RHS, 2002).

Cultivation: Polypody prefers moist, well drained, humus rich soil in partial shade. It is propogated by spores in autumn, or by division in spring or early summer. The rhizomes can be harvested in autumn (RHS, 2002).

Parts used: Although referred to as a root in the traditional literature, the part used is more accurately described as a rhizome.

Phytochemistry: Saponins (Osladin), Triterpinoids (Ecdysteroids), Phenols (Phloroglucins), Volatile oils, Fixed Oils (Chevallier, 2000; Jizba, Dolejš, Herout, & Šorm, 1971)

Traditional uses: Gerard tells us that Galen writes “…polypodie doth dry, but yet without biting”, he also reports Dioscorides saying “…that it is of power to purge and to draw forth choler and phlegm.” He goes on to say “For in very deed Polypody of itself does not purge at all, but only serueth [supports] a little to make the belly soluble” and he recommends combining it with Marshmallow or other things that “…moove the stoole by their slipperiness.” (Gerard, 1633 [2015]). Culpeper describes Polypody as a cold and dry remedy of Saturn good for ‘purging melcancholy’. He goes onto say “It dries up thin humours, digests thick and tough phlegm, and thin phlegm also, even from the joints”. He also mentions combining it with Marshmallow. He also recommends it for the quartan ague, against melancholy, and troublesome sleep and dreams, and the dried root for nasal polyps (Culpeper, 1653 [2007]). An Eighteenth century Irish herbal says “It is very good against bowel disorders and purges bilious substances, …it is good for opening obstructions of the spleen, and easing fevers”(K'Eogh, 1735 [1986]). Mrs Grieve continues the purgative theme recommending the root as a mild laxative, and adding a tonic in dyspepsia and loss of appetite, an alterative in skin condition, and also useful in dry coughs and catarrhal conditions (Grieve, 1931).

Scientific research: There is remarkably little scientific research on Polypodium vulgare, what there is is mainly analyses of its compounds. The saponin osladin is responsible for the roots sweet taste (Jizba et al., 1971). The rhizome also contains significant quantities of Potassium, Sodium, Calcium and Magnesium (EMEA, 2008). In vitro anti-viral properties were found in the rhizome when tested on monkey cells (Husson GP, 1986). In vivo on rats have demonstrated that the rhizome had a sedative activity, prolonged sleeping time, was anticonvulsant, and antipyretic (Mannan A, 1989).

Summary of action: Laxative, Cholagogue, Expectorant (Barker, 2001) (Chevallier, 2000)

Indications: Polypody is useful in mild constipation (particularly in children) and one that can be used for a reasonable length of time. It also stimulates bile flow making it useful in cases of indigestion and jaundice. It also has a mildly stimulating effect on the respiratory system making it useful in congestion and coughs (Barker, 2001) (Chevallier, 2000).

Cautions: None known except the root may cause a harmless skin rash on some susceptible individuals (Grieve, 1931).

Dosage: Decoction. Half a tsp ground rhizome to a cup of water simmered for 15 minutes, half a cup 3 times a day. Liquid extract (2:1) 20-40ml/week (Bartram, 1995)

References

Barker, J. (2001). The Medicinal Flora of Britain and Northwestern Europe: Winter Press.

Bartram, T. (1995). Thomas Bartram's Encyclopedia of Herbal Medicine. Dorset: Grace Publishers.

Chevallier, A. (2000). Encyclopedia of Herbal medicine. Gret Britain: Dorling Kindersley.

Culpeper, N. (1653 [2007]). Culpeper's Complete Herbal. Hertfordshire: Wordsworth Editions.

EMEA. (2008). ASSESSMENT REPORT ON POLYPODIUM VULGARE L., RHIZOMA.

Gerard, J. (1633 [2015]). The Herbal or general History of Plants (J. Johnson Ed.). LONDON: Dover.

Grieve, M. (1931). A Modern herbal. London: Jonathan Cape.

Husson GP, V. R., Delaveau P. (1986). Recherche de Propriétés Antivirales de quelques Extraits D’orgine Naturelle. Ann. Pharmaceutiques Françaises, 44, 41-48.

Jizba, J., Dolejš, L., Herout, V., & Šorm, F. (1971). The structure of osladin - the sweet principle of the rhizomes of polypodium vulgare L. Tetrahedron Letters, 12(18), 1329-1332.

K'Eogh, J. (1735 [1986]). Botanalogica Universalis Hibernica (An Irish Herbal) (M. Scott Ed.): Aquarian press.

Mannan A, K. R., Asif M. (1989). Pharmacodynamic studies on Polypodium vulgare (Linn.). Indian Journal of Experimental Biology, 27, 556-560.

RHS. (2002). New Encyclopedia of Herbs and their Uses (Revised ed.). London: Dorling Kindersley.