''Athyrium distentifolium'' commonly known as alpine lady-fern is a

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...

found in widely 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 as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...

. It is a common upland variety above 600 metres in the Highlands of

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

, with more than 10% of the UK population being found in the

Cairngorm mountains The Cairngorms ( gd, Am Monadh Ruadh) are a mountain range in the eastern Highlands of Scotland closely associated with the mountain Cairn Gorm. The Cairngorms became part of Scotland's second national park (the Cairngorms National Park) on 1 ...

, especially on scree slopes in

Glen Feshie The River Feshie ( gd, Fèisidh / Abhainn Fhèisidh) is a major right bank tributary of the River Spey in north-east Scotland. It rises in the remote countryside of the Glenfeshie Forest, flowing initially eastwards before turning sharply to the ...

, and on

Ben Avon Ben Avon ( gd, Beinn Athfhinn, 'mountain of the Avon') is a mountain in the Cairngorms of Scotland. It is a sprawling mountain with a broad summit plateau dotted with granite tors. One of these marks the summit, called ''Leabaidh an Daimh Bhuid ...

, Ben MacDui and Beinn a' Bhùird. Regarded as nationally scarce, it is a snow-tolerant species. The stunted form var. ''flexile'', which is found at 750 metres and above, is found at only 4 sites and is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Scotland."Species Action Plan: Newman's Lady Fern (Athyrium flexile)"
BAP. Retrieved 29 June 2008. The subspecies ''americanum'' is found in the mountains of western

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

and coastal

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...

,"Plants Profile: Athyrium americanum"
USDA Retrieved 24 June 2008. and is sometimes classified as a separate species ''Athyrium americanum''. Athyrium distentifolium JHT IMG 8322.jpg, ''Athyrium distentifolium ssp. americanum'' Athyrium distentifolium JHT IMG 7054.jpg, ''Athyrium distentifolium ssp. americanum lower surface of leaf''

References

External links

distentifolium Flora of Scotland Ferns of the United States {{Polypodiales-stub