Diapensia lapponica is a plant in the family
DiapensiaceaeDiapensiaceae is a small family of flowering plants, comprising 20 species in seven genera.Genera*Berneuxia Decne.*Diapensia L.*Diplarche Hook.f. & Thomson*Galax Sims*Pyxidanthera Michx.*Schizocodon Siebold & Zucc....
, and the only species in the genus
Diapensia. It is a
circumborealThe Circumboreal Region is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan...
arctic-alpineAn arctic-alpine taxon is one whose natural distribution includes the Arctic and more southerly mountain ranges, particularly the Alps. The presence of identical or similar taxa in both the tundra of the far north, and high mountain ranges much further south is testament to the similar...
species which grows on exposed rocky ridges that are kept free from snow by high winds .
It is a small
cushionA cushion plant is a compact, low growing, mat forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world...
-forming
evergreenIn botany, an evergreen plant is a plant having leaves all year round. This contrasts with deciduous plants, which completely lose their foliage for part of the year....
perennialA perennial plant or perennial is a plant that lives for more than two years. When used by gardeners or horticulturalists, this term applies specifically to perennial herbaceous plants...
shrubA shrub or bush is a horticultural rather than strictly botanical category of woody plant, distinguished from a tree by its multiple stems and lower height, usually less than 5-6 m tall. A large number of plants can be either shrubs or trees, depending on the growing conditions they experience...
, up to 15 cm in height. It has oval blunt leathery toothless leaves, up to 1 cm long, which are arranged in dense rosettes.
Diapensia lapponica is a plant in the family
DiapensiaceaeDiapensiaceae is a small family of flowering plants, comprising 20 species in seven genera.Genera*Berneuxia Decne.*Diapensia L.*Diplarche Hook.f. & Thomson*Galax Sims*Pyxidanthera Michx.*Schizocodon Siebold & Zucc....
, and the only species in the genus
Diapensia. It is a
circumborealThe Circumboreal Region is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan...
arctic-alpineAn arctic-alpine taxon is one whose natural distribution includes the Arctic and more southerly mountain ranges, particularly the Alps. The presence of identical or similar taxa in both the tundra of the far north, and high mountain ranges much further south is testament to the similar...
species which grows on exposed rocky ridges that are kept free from snow by high winds .
It is a small
cushionA cushion plant is a compact, low growing, mat forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world...
-forming
evergreenIn botany, an evergreen plant is a plant having leaves all year round. This contrasts with deciduous plants, which completely lose their foliage for part of the year....
perennialA perennial plant or perennial is a plant that lives for more than two years. When used by gardeners or horticulturalists, this term applies specifically to perennial herbaceous plants...
shrubA shrub or bush is a horticultural rather than strictly botanical category of woody plant, distinguished from a tree by its multiple stems and lower height, usually less than 5-6 m tall. A large number of plants can be either shrubs or trees, depending on the growing conditions they experience...
, up to 15 cm in height. It has oval blunt leathery toothless leaves, up to 1 cm long, which are arranged in dense rosettes. It bears solitary white flowers, on stems up to 3 cm tall.
It could be aged by counting growth-rings, and on this basis, many Canadian plants have been shown to live to over a century old .
Two subspecies are recognised:
- Diapensia lapponica subsp. lapponica in eastern North America
North America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
, GreenlandGreenland is an autonomous constituent country within the Kingdom of Denmark located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago...
, ScotlandScotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, ScandinaviaScandinavia is a geographical region in northern Europe that includes, and is named after, the Scanian Province. It consists of the kingdoms of Norway, Sweden, and Denmark...
, and western ArcticThe Arctic is the region around the Earth's North Pole, opposite the Antarctic region around the South Pole. The Arctic includes the Arctic Ocean and parts of Canada, Greenland , Russia, the United States , Iceland, Norway, Sweden and Finland.The word Arctic comes from the Greek αρκτικός , "near...
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
- Diapensia lapponica subsp. obovata in eastern Arctic
The Arctic is the region around the Earth's North Pole, opposite the Antarctic region around the South Pole. The Arctic includes the Arctic Ocean and parts of Canada, Greenland , Russia, the United States , Iceland, Norway, Sweden and Finland.The word Arctic comes from the Greek αρκτικός , "near...
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
, KoreaKorea is a civilization and formerly unified nation currently divided into two states. Located on the Korean Peninsula, it borders China to the northwest, Russia to the northeast, and is separated from Japan to the east by the Korea Strait....
, Japanis an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, AlaskaAlaska is the largest state of the United States of America by area; it is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and the YukonYukon , or The Yukon, is the westernmost and smallest of Canada's three federal territories. It was named after the Yukon River, Yukon meaning "Great River" in Gwich’in....
Status in Britain
In
BritainGreat Britain is an island lying to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island. With a population of about 59.6 million people, it is the third most populated island on Earth. Great Britain is surrounded by over 1000 smaller...
,
Diapensia is found only at a single site, Sgurr an Utha , near
GlenfinnanGlenfinnan is a village in Lochaber area of the Highlands of Scotland. It is located at the northern end of Loch Shiel, at the foot of Glenfinnan.See http://wikitravel.org/en/Glenfinnan for more details....
in
LochaberLochaber is one of the 16 ward management areas of the Highland Council of Scotland and one of eight former local government districts of the two-tier Highland region...
, the species' most southerly site in Europe. Here, the species occurs on acidic soil among stones on the ridge between the summit of Sgurr an Utha and the adjoining hill called Fraoch-bheinn, at 760 to 780 metres above sea-level. Its total extent at this site is less than 5,000 m². A total of 1,200 clumps or mats have been counted, and monitoring since 1980 has not detected any change in this population.
The discovery of
Diapensia took place in July 1951; C. F. Tebbutt, a birdwatcher, found the plant, recognising it as "something different" .
Diapensia was one of a trio of Arctic plants discovered in Scotland in the early 1950s. Although no new species to Britain had been discovered in Scotland since Victorian times, in 1950, the Arctic plant
Koenigia islandica had been found on the Isle of Skye, and in 1952,
Artemisia norvegica was found on
Cul MorCùl Mòr is a shapely, twin summited mountain in the far north west of Scotland whose higher summit is the highest point of Inverpolly. It is almost completely separated from its southern neighbour, Cùl Beag...
. A photograph of the plant by Robert Moyes Adam taken on 14 June 1952 (soon after the initial discovery) is held by the St Andrews University Library .
It flowers at this site in May or June, the exact time varying from year to year. Some sources state that the species is found at a second site but recent sources state that this is not the case .
The plant is listed in the 3rd edition of the British vascular plant
Red Data BookThe IUCN Red List of Threatened Species , founded in 1948, is the world's most comprehensive inventory of the global conservation status of plant and animal species. The International Union for the Conservation of Nature and Natural Resources is the world's main authority on the conservation...
as
vulnerableA vulnerable species is a species which is likely to become endangered unless the circumstances threatening its survival and reproduction improve...
. It is also protected under Schedule 8 of the
Wildlife and Countryside Act 1981The Wildlife and Countryside Act 1981 is an Act of Parliament in the United Kingdom which aims to protect the wildlife and countryside of the United Kingdom...
.