Hybridizes with :

• Western-Scaly Male-Fern (Dryopteris affinis) to produce Dryopteris × complexa.
• Mountain Male-Fern (Dryopteris oreades) to produce Dryopteris × montaniae.

Many similarities to : Mountain Male-Fern (Dryopteris oreades) which appears like a smaller version, but with slightly fewer sori (4-6) and with Western-Scaly Male-Fern (Dryopteris affinis) which seems to have slightly more sori (6-9).

The specific epithet 'filix-mas' of the scientific name refers to it being a male plant ('filix-femina' being the opposite of 'filix-mas').

One of the most common Ferns of the UK. The leaves sometimes over-winter (in mild winters). New leaf growth happens in April. Leaves are mid-green and taper at both ends. Spores are ripe August to November.

Grows in woods, hedge-banks, screes and rocks and is widespread being absent from a few places in Lincolnshire and the East Midlands, and several locations in Scotland. Less frequent in Ireland.

Both Male-Fern and Lady-Fern (Athyrium filix-femina) are said to contain a toxic oleoresin called Filicic Acid which has the ability to paralyse tapeworms and other intestinal parasites. The roots of this species of fern contain between 1.5 - 2,5% of Filicaic Acid. Its use medicinally should only be practised by qualified practitioners and be followed by a non-oily purgative such as magnesium sulfate (MgSO₄ Epsom Salts), after all, it is poisonous!

Fresh plants also contain the enzyme Thiaminase (as does Bracken) which destroys Vitamin B1 (Thiamin) leading to vitamin B deficiency.

ACYLPHLOROGLUCINOLS

An extract from the root or rhizome of the Male-Fern (and other species belonging to the Dryopteris Genus) is used as the drug Aspidium, which is used to treat Tapeworm and also cancerous tumours, as a contraceptive and as a bacteriocide. The extract contains the flavone Dryopterin, Triterpenoids and a plethora of PhloroGlucinol derivatives which are based upon PhloroGlucinol. PhloroGlucinol exists in a resonance hybrid equilibrium of two tautomers, one 1,3,5-Trihydroxybenzene which has phenol-like characteristics and the other 1,3,5-Cyclohexanetrione which exhibits ketone-like characteristics. Here the hydrogen atoms of the -OH are shared between the oxygen atoms and the carbon ring. This is probably a direct result of the alternate structure, and probably would not occur for 1,2,5- or 1,2,3- arrangements of the -OH groups. It exhibits so-called keto-enol tautomerism. As a result phloroglucinol is polyfunctional. Brown Algae also produces Phloroglucinol derivatives known as Phlorotannins. Phloroglucinol itself is a useful starting compound for the manufacture of both pharmaceuticals and explosives. It itself is also used as a treatment for gallstones, spasmodic pain and other gastrointestinal disorders. The Phloroglucinol derivatives present in the extract (called crude Filicin mixture) are condensation of various phloroglucinols to form one, two, three or four-ring 'polymers' of phloroglucinol linked by methylene bridges. They are not exact polymers, for the acyl moieties on the individual phloroglucinol molecules differs slightly. Acyl Moieties in Phloroglucinols (A) acetyl groups [R = methyl] (P) propionyl groups [R = ethyl] (B) butyryl groups [R = n-propyl] (iB) isobutyryl groups [R = isopropyl] (V) n-valeryl groups [R = n-butyl] The (B) butyryl group [R = n-propyl] is the most common. The letters appear after the name to indicate which groups and in which order they occur in the 'polymers'. Thus Albaspidin-AB has an acetyl group on the first ring, and a butyryl group on the second ring. A prenylated PhloroGlucinol Hyperforin also occurs in species of St John's Wort, see Slender St John's Wort. Constituents of the crude Filicin mixture in Male-Fern Flavaspidic Acid-BB >20% ParaAspidin-BB >20% Filixic Acid-BBB >20% Filixic Acid-ABB 5% - 10% Flavaspidic Acid-AB 5% - 10% Filixic Acid-ABA 1% - 5% Trisdesaspidin-BBB 1% - 5% Trisflavaspidic Acid-BBB 1% - 5% Tetraflavaspidic Acid-BBBB 1% - 5% Trisflavaspidic Acid-ABB 1% - 5% Trispara-aspidin-BBB c.2% Aspidinol B <1% NorFlavaspidic Acid-BB <1% NorFlavaspidic Acid-AB <1% ParaAspidin-AB <1% Albaspidin-BB <1% Albaspidin-AB <1% Albaspidin-AA <1% TetraAlbaspidin-ABBA <1% TetraAlbaspidin-BBBB <1% For other Dryopteris species the constituents and amounts differ There are three main series of dimers, the Albaspidins, the Flavaspidic Acids and the NorFlavaspidic Acids and several other series including the Aspidins, Para-Aspidins and Iso-Aspidins. ALBASPIDINS The Albaspidins are based upon two Filicinic Acid moieties linked by a methylene bridge, with various groups attached at the positions shown by R1 and R2 in the diagram below. Albaspidin-AA      R1 = R2 = CH3 The albaspidins present in the rhizomes are: Albaspidin AA      R1 = R2 = CH3 Albaspidin-AB      R1 = CH3; R2 = n-propyl Albaspidin-BB      R1 = R2 = n-propyl Albaspidin-PB      R1 = ethyl; R2 = n-propyl Albaspidin-PP      R1 = R2 = ethyl Albaspidin-AP      R1 = CH3; R2 = ethyl Albaspidin-iBiB    R1 = R2 = isopropyl Albaspidin-BV      R1 = n-propyl; R2 = n-butyl Albaspidin-iBV     R1 = isopropyl; R2 = n-butyl Albaspidin-VV      R1 = R2 = n-butyl FLAVASPIDIC ACIDS Flavaspidic Acid-AB Flavaspidic Acid-BB Flavaspidic Acid-AP Flavaspidic Acid-PA Flavaspidic Acid-PB Flavaspidic Acid-BP Flavaspidic Acid-PP Flavaspidic Acid-VV Flavaspidic Acid-VB Flavaspidic Acid-BV Flavaspidic Acids seem to be the most pharmacologically active phloroglucinol in Male-Fern and exhibits anti-bacterial action and taeniacidal activity against tapeworms. Those tested were Flavaspidic Acid-AB and Flavaspidic Acid-PB. However, Desaspidin, which is found in Broad Buckler-Fern (Dryopteris dilatata), is the more potent. NORFLAVASPIDIC ACIDS NorFlavaspidic Acid-AB NorFlavaspidic Acid-BB NorFlavaspidic Acid-AP NorFlavaspidic Acid-PB ASPIDINS Similar variations exist for the Aspidins, Para-Aspidins and iso-Aspidins shown above. There are also similar series of two-ringed AcylPhloroglucinol derivatives called the Desaspidins, the Phloraspins, the Phloraspidinols, the Phlorapyrones, the Abbreviatins and the Margaspidins, all with various substitutions or re-arrangements in the position of the acyl moieties. The variety of acylphloroglucinols is too large to show here and many may not be produced in Male-Fern but in other Dryopteris species. DESASPIDINS Desaspidin-AB Desaspidin-BA Desaspidin-BB Desaspidin-PB Desaspidin-BP Desaspidin-AP Desaspidin-PA Desaspidin-PP Desaspidin-VV Desaspidin-VB Desaspidin-BV The Desaspidins, found in Broad Buckler-Fern (Dryopteris dilatata) are more potent anti-bacterial and taeniacidal against tapeworms than are the Flavaspidic Acids. The more usual Desapidins are Desaspidin-BB and Desaspidin-AB. TRIMERS and HIGHER POLYMERS of ACYLPHLOROGLUCINOLS A third Felixic Acid, Felixic Acid-ABB, is also produced within Male-ferns, but the reader can interpolate the structural formulae from the above two. Penta-Albaspidin-BBBBB and Hexa-Albaspidin-BBBBBB also exist, where the outer two rings are Filicinic Acid derivatives and the inner moieties are repeats of the Phloroglucinol derivatives just as they are in the Tetra-Albaspidins above.

A FLAVONE
Male-Fern also contains the novel C17 flavone Dryopterin which has an extra fused lactone ring (lowest ring). This constitutes part of the many components of the Filicin which can be extracted from the rhizomes, and may have contributed to its pharmacological properties. It should be pointed out that the preparation is no longer used medicinally because of its toxicity.