This species is often put into the separate genus Ceterach Willdenow as Ceterach officinarum Willd., on the basis of its peculiar pinnatipartite fronds, submarginally anastomosing veins, and the dense, abaxial scale covering. However, all these characters also occur in other clades within the family, and molecular studies (Van den heede et al., Amer. J. Bot. 90: 481–495. 2003) have shown that “Ceterach” consists of two separate clades both nested within Aspleniaceae and not meriting generic status[].

Common Name: Scale Fern

General Information

Asplenium ceterach is an evergreen fern growing from a short and erect or spreading rhizome. It produces a cluster of fronds up to 20cm long and 5cm wide[].
The plant is harvested from the wild for local use as a medicine. It is grown as an ornamental in gardens.

Known Hazards

Although we have found no reports of toxicity for this species, a number of ferns contain carcinogens so some caution is advisable[].
Many ferns also contain thiaminase, an enzyme that robs the body of its vitamin B complex. In small quantities this enzyme will do no harm to people eating an adequate diet that is rich in vitamin B, though large quantities can cause severe health problems. The enzyme is destroyed by heat or thorough drying, so cooking the plant will remove the thiaminase[].

Botanical References

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Range

Eurasia - Britain to Spain and eastwards th the Caucasus, central Asia, Pakistan; Africa - Macaronesia, north Africa to Egypt, Levant

Habitat

Limestone rocks and mortared walls[]. Dry rock crevices at elevations from 1,400 - 2,600 metres in western China[].

Properties

Medicinal Rating
Habit	Evergreen Fern
Height	0.15 m
Cultivation Status	Ornamental, Wild

Cultivation Details

A calcicole plant, it requires a freely draining but moist alkaline soil[]. It tolerates full sun but prefers a position with at least part-day shade[] and also grows in deep shade[]. Plants can be grown in old brick walls[].
In very dry conditions the fronds roll up into a tube shape, unrolling with the return of moisture[].
A very ornamental plant[].
Members of this genus are rarely if ever troubled by browsing deer[].

Edible Uses

None known

Medicinal

The whole plant is antitussive and diuretic[]. It is widely used in the Mediterranean to treat gravel in the urine and is also used with other mucilaginous plants to treat bronchial complaints[]. The taste is very bitter and needs to be sweetened with other herbs such as liquorice[].
The plant is harvested from late spring to summer and can be dried for later use[].
Some caution should be employed in its use since it has not been fully tested[].

Other Uses

None known

Propagation

Spores - best sown as soon as they are ripe on the surface of a humus-rich sterilized soil. Keep the compost moist, preferably by putting a plastic bag over the pot. Germinates in spring[]. Spring sown spores germinate in 1 - 3 months at 15°c[]. Pot on small clumps of plantlets as soon as they are large enough to handle and grow them on in light shade in a cold frame or greenhouse. Keep them humid until they are well established. When they are at least 15cm tall, plant them out into their permanent positions in late spring or early summer.