''Cystopteris dickieana'', commonly known as Dickie's bladder-fern, is a

fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...

with a wide distribution in the

Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...

. There is debate amongst botanists as to whether it is a species in its own right, or a variety or subspecies of '' C. fragilis''.

Distribution and habitat

''C. dickieana'' is native to several

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

an countries including

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

, and

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, and in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, and also north

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

in the

Atlas Mountains The Atlas Mountains are a mountain range in the Maghreb in North Africa. They separate the Sahara Desert from the Mediterranean Sea and the Atlantic Ocean; the name "Atlantic" is derived from the mountain range, which stretches around through M ...

. It is typically found in

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

habitats below the tree-line, although it also grows at lower altitudes in locations with cool summers.

Discovery and Victorian collectors

The first recorded discovery of the plant was made by William Knight, Professor of Natural Philosophy at

Marischal College Marischal College ( ) is a large granite building on Broad Street in the centre of Aberdeen in north-east Scotland, and since 2011 has been the headquarters of Aberdeen City Council. The building was constructed for and is on long-term lease fr ...

Aberdeen Aberdeen ( ; ; ) is a port city in North East Scotland, and is the List of towns and cities in Scotland by population, third most populous Cities of Scotland, Scottish city. Historically, Aberdeen was within the historic county of Aberdeensh ...

. Knight came across a small population growing on base-rich rocks in a sea cave (known locally as a "yawn") on the coast of

Kincardineshire Kincardineshire or the County of Kincardine, also known as the Mearns (from the Scottish Gaelic meaning "the stewartry"), is a Shires of Scotland, historic county, registration county and lieutenancy areas of Scotland, lieutenancy area on the ...

. The first publication to record it was the 1838 ''Flora Aberdonenis'' which included a note of its occurrence written by a pupil of Knight's, George Dickie. Dickie also sent a live specimen to Robert Sim, a nurseryman from

Kent Kent is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Essex across the Thames Estuary to the north, the Strait of Dover to the south-east, East Sussex to the south-west, Surrey to the west, and Gr ...

, who believed it to be a new species and published his views in the 1848 edition of the ''Gardener's and Farmer's Journal'', naming it ''C. dickieana''. Rarer British ferns came under severe threat from

Victorian Victorian or Victorians may refer to: 19th century * Victorian era, British history during Queen Victoria's 19th-century reign ** Victorian architecture ** Victorian house ** Victorian decorative arts ** Victorian fashion ** Victorian literatur ...

fern collectors in the mid 19th century in Scotland, a period of collecting that became known as ''

Pteridomania Pteridomania or fern fever was a Victorian craze for ferns. Decorative arts of the period presented the fern motif in pottery, glass, metal, textiles, wood, printed paper, and sculpture, with ferns "appearing on everything from christening ...

'' (or "fern-fever"). In 1860 Dickie reported that the original colony had been collected to

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

from the yawn where its original discovery had occurred. The evidence for this is conflicting, but today there is a population of more than 100 plants there, where it grows in a roof fissure in the company of ''

Athyrium filix-femina ''Athyrium filix-femina'', the lady fern or common lady-fern, is a large, feathery species of fern native to temperate Asia, Europe, North Africa, Canada and the US. It is often abundant (one of the more common ferns) in damp, shady woodland envi ...

'' and '' Dryopteris dilatata''.

Taxonomic controversy

Taxonomic classification within the genus ''

Cystopteris ''Cystopteris'' is a genus of ferns in the family Cystopteridaceae. These are known generally as bladderferns or fragile ferns. They grow in temperate areas worldwide. This is a very diverse genus and within a species individuals can look quite ...

'' is complex. Within a year of Sim's publication

Thomas Moore Thomas Moore (28 May 1779 – 25 February 1852), was an Irish writer, poet, and lyricist who was widely regarded as Ireland's "National poet, national bard" during the late Georgian era. The acclaim rested primarily on the popularity of his ''I ...

stated his view was that, on balance, Dickie's Bladder-fern was a variety of ''C. fragilis''. Various opinions have been published over the intervening years, with a consensus that ''C. dickeana'' was a separate species emerging in the 1930s, although recent research suggests that Moore's caution may have been appropriate.Parks, J. C., Dyer, F. A. and Lindsay, S. (2000
"Allozyme, Spore and Frond Variation in Some Scottish Populations of the Ferns Cystopteris dickieana and Cystopteris fragilis"
''Edinburgh Journal of Botany'' 57: 83-105. Cambridge University Press. Retrieved 1 June 2008. ''C. dickeana'' has broader, less divided and more closely spaced

pinnae Pinna may refer to: Biology * Pinna (anatomy), or auricle, the outer part of the ear * ''Pinna'' (bivalve), a genus of molluscs * Pinna (botany), a primary segment of a compound leaf People Surname * Christophe Pinna (born 1968), French marti ...

than ''C. fragilis'', and the spores of the former are typically wrinkled and ridged rather than the spiny form of the latter's. However, there are significant variations within the populations of both forms and these characteristics are by no means fixed. On the other hand, there is also evidence that crosses of the two types produce sterile hybrids. ''C.'' × ''montserratii'' is a proposed hybrid between ''C. dickeana'' and ''C. fragilis''. The treatment of ''Cystopteris'' in the ''Flora of North America'' (1993) regards ''Cystopteris dickieana'' as a synonym of ''Cystopteris fragilis''.

Conservation

In the UK the fern's natural population is entirely confined to Scotland, where it occurs at a number of

locations (up to 420 m altitude) as well as the first-discovered coastal cave; it is protected under the

Wildlife and Countryside Act 1981 The Wildlife and Countryside Act 1981 (c. 69) is an act of Parliament in the United Kingdom implemented to comply with European Council Directive 79/409/EEC on the conservation of wild birds. In short, the act gives protection to native species ...

."Scotland's Wildlife: The Law and You"
SNH. Retrieved 4 July 2008.

References

Lusby, Phillip and Wright, Jenny (2002) ''Scottish Wild Plants: Their History, Ecology and Conservation''. Edinburgh. Mercat.

Notes

External links

Illustration
{{Taxonbar, from=Q2176480 dickieana Ferns of Asia Ferns of Europe Ferns of the Americas Ferns of Canada Ferns of the United States