Ophioglossum azoricum

Ophioglossum azoricum
Ophioglossum azoricum in coastal grassland, Dooncarton, Co. Mayo
Scientific classification
Kingdom:	Plantae
Division:	Pteridophyta
Class:	Psilotopsida
Order:	Ophioglossales
Family:	Ophioglossaceae
Genus:	Ophioglossum
Species:	O. azoricum
Binomial name
Ophioglossum azoricum C. Presl 1984
Synonyms
Ophioglossum vulgatum L. subsp. ambiguum (Coss. & Germ.) E.F.Warb. Ophioglossum sabulicolum Sauzé & Maillard Ophioglossum vulgatum L. subsp. vulgatum var. minus Ostenf. & J.Gröntved Ophioglossum vulgatum L. subsp. vulgatum var. islandicum A$A.Löve & D.Löve Ophioglossum vulgatum L. subsp. polyphyllum auct., non A.Braun Ophioglossum sabulicola Sauzé

Ophioglossum azoricum, the small adder's-tongue fern, is a small fern of the family Ophioglossaceae.

Distribution

Ophioglossum azoricum is native to islands in the northern Atlantic Ocean and adjacent westernmost Europe from the Azores north to western France, the British Isles, Iceland and Greenland. It also occurs in the Toscana region of Italy.^[1]

This species mostly occurs on bare or shortly vegetated ground on exposed coastal clifftops. An exception to this habitat preference is populations in the New Forest, Hampshire where plants occur in tightly grazed damp grassland in a non-maritime setting.^[2]

In Iceland, ^[3] and Greenland, ^[4] it is restricted to geothermal areas where higher temperatures allow its survival. This species is on the Icelandic list of endangered species.

Description

The frond of Ophioglossum azoricum consists of a single, pointed leaf blade and a narrow pointed spore-bearing spike on a stalk. The spike has about 4-18 segments on each side, each of which opens up when ripe to release spores. The sterile blades are broadest near the middle and taper towards both ends.

Taxonomy

This taxon is sometimes treated as a subspecies of Ophioglossum vulgatum, as Ophioglossum vulgatum ssp. ambiguum (Coss. & Germ.) E.F. Warburg.

This species is thought to be derived from a hybrid between Ophioglossum vulgatum and Ophioglossum lusitanicum.^[5]

This species has a chromosome number of 2n=c.480.^[5]

References

1. Ophioglossum azoricum at Schede di botanica
2. Ophioglossum azoricum at Online Atlas of the British and Irish Flora
3. Löve Á. (1983) Flora of Iceland.Almenna Bókafélagid
4. Lid J, Lid DT, Elven R. 1994 Norsk flora. 6th edition. Oslo: Det Norske Samlaget
5. Stace C. (1997). New Flora of The British Isles, second edition. Cambridge: Cambridge University Press

External links

• BSBI map: Distribution of Ophioglossum azoricum in the British Isles
• "The Ferns (Filicopsida) of the British Isles" — Ophioglossum azoricum — by L. Watson and M. J. Dallwitz.
• West Highland Flora: species account for 'Ophioglossum azoricum