Saxifraga stellaris
Encyclopedia
Saxifraga stellaris, the starry saxifrage or hairy kidney-wort, is an Arctic-alpine
Arctic-alpine
An 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 of saxifrage
Saxifrage
Saxifraga is the largest genus in the family Saxifragaceae, containing about 440 species of Holarctic perennial plants, known as saxifrages. The Latin word saxifraga means literally "stone-breaker", from Latin + ...

. It produces panicles of 5–10 white flowers on a stem up to 20 cm (7.9 in) tall, rising from a basal leaf rosette. One subspecies is found from eastern Canada to Russia, including the British Isles, while another is found in the mountains of southern Europe.

Description

Saxifraga stellaris grows as a leaf rosette
Rosette (botany)
In botany, a rosette is a circular arrangement of leaves, with all the leaves at a single height.Though rosettes usually sit near the soil, their structure is an example of a modified stem.-Function:...

, which produces a generally leafless stem up to 20 centimetres (7.9 in) tall. The leaves are toothed and somewhat fleshy, ovate or obovate, and without an obvious petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...

. They are typically 3 cm (1.2 in) long (varying from 1 to 5 cm or 0.393700787401575 to 2 ), with a cuneate (wedge-shaped) base.

The flowers are borne in a loose panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....

 comprising 5–10 flowers; each flower has deflexed sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...

s, surrounding five white petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...

s, 3–6 mm (0.118110236220472–0.236220472440945 ) long, with two yellow or red spots near the base. The anthers are also red or yellow. Flowers are borne from June to August.

The seeds are dark brown, glabrous, 0.6 millimetre long, and 0.3 millimetre wide. They are elliptic, ovoid or reniform in shape, with longitudinal ribs bearing spines. S. stellaris has a chromosome number of 2n = 28.

Distribution and ecology

Saxifraga stellaris has an Arctic-alpine distribution
Arctic-alpine
An 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...

. It is found from Baffin Island
Baffin Island
Baffin Island in the Canadian territory of Nunavut is the largest island in the Canadian Arctic Archipelago, the largest island in Canada and the fifth largest island in the world. Its area is and its population is about 11,000...

, Labrador
Labrador
Labrador is the distinct, northerly region of the Canadian province of Newfoundland and Labrador. It comprises the mainland portion of the province, separated from the island of Newfoundland by the Strait of Belle Isle...

 and Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

 to Arctic Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

, including Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...

, Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...

 and the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...

. Further south, it is found from the Sierra Nevada
Sierra Nevada (Spain)
The Sierra Nevada is a mountain range in the region of provinces of Granada and Almería in Spain. It contains the highest point of continental Spain, Mulhacén at 3478 m above sea level....

 in southern Spain to the eastern Carpathians, including lower ranges such as the Massif Central
Massif Central
The Massif Central is an elevated region in south-central France, consisting of mountains and plateaux....

.

In the Arctic, S. stellaris may occur down to sea level. Within the British Isles, S. stellaris is abundant in North Wales
North Wales
North Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...

, Northern England
Northern England
Northern England, also known as the North of England, the North or the North Country, is a cultural region of England. It is not an official government region, but rather an informal amalgamation of counties. The southern extent of the region is roughly the River Trent, while the North is bordered...

 and Scotland
Scotland
Scotland 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...

, reaching the summit of Ben Nevis
Ben Nevis
Ben Nevis is the highest mountain in the British Isles. It is located at the western end of the Grampian Mountains in the Lochaber area of the Scottish Highlands, close to the town of Fort William....

 (1344 m or 4,409.4 ft), but is only found locally in Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

. Its southernmost stations in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

 are the slopes of Plynlimon
Plynlimon
Plynlimon is the highest point of the Cambrian Mountains in Wales, and the highest point in Mid Wales. It is a massif that dominates the countryside of northern Ceredigion....

 and the Rheidol valley; it does not occur in the mountains of South Wales
South Wales
South Wales is an area of Wales bordered by England and the Bristol Channel to the east and south, and Mid Wales and West Wales to the north and west. The most densely populated region in the south-west of the United Kingdom, it is home to around 2.1 million people and includes the capital city of...

. In the Vosges
Vosges mountains
For the department of France of the same name, see Vosges.The Vosges are a range of low mountains in eastern France, near its border with Germany. They extend along the west side of the Rhine valley in a northnortheast direction, mainly from Belfort to Saverne...

, it occurs around 3600 ft (1,097.3 m), but only rarely below 4300 foot in the Swiss Alps
Swiss Alps
The Swiss Alps are the portion of the Alps mountain range that lies within Switzerland. Because of their central position within the entire Alpine range, they are also known as the Central Alps....

. In the Sierra Nevada
Sierra Nevada (Spain)
The Sierra Nevada is a mountain range in the region of provinces of Granada and Almería in Spain. It contains the highest point of continental Spain, Mulhacén at 3478 m above sea level....

 of southern Spain, it lives at up to 3350 m (10,990.8 ft).

Saxifraga stellaris lives in damp environments, such as wet flushes, beside streams or springs, or on wet rock ledges. It is self-compatible, but its flowers are protandrous, and are usually pollinated
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...

 by flies
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...

.

Taxonomy

Saxifraga stellaris was first described
Alpha taxonomy
Alpha taxonomy is the discipline concerned with finding, describing and naming species of living or fossil organisms. This field is supported by institutions holding collections of these organisms, with relevant data, carefully curated: such institutes include natural history museums, herbaria and...

 by Carl Linnaeus in his 1753 work Species Plantarum
Species Plantarum
Species Plantarum was first published in 1753, as a two-volume work by Carl Linnaeus. Its prime importance is perhaps that it is the primary starting point of plant nomenclature as it exists today. This means that the first names to be considered validly published in botany are those that appear...

. Linnaeus noted the species' occurrence in the mountains of Spitsbergen
Spitsbergen
Spitsbergen is the largest and only permanently populated island of the Svalbard archipelago in Norway. Constituting the western-most bulk of the archipelago, it borders the Arctic Ocean, the Norwegian Sea and the Greenland Sea...

, Lapland
Lapland
Sápmi is the name of the cultural region traditionally inhabited by the Sami people. Sápmi is located in Northern Europe and includes the northern parts of Fennoscandia. The region stretches over four countries: Norway, Sweden, Finland, and Russia. Sápmi is the name in North Sámi, while the Julev...

, Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

, Styria and Westmorland
Westmorland
Westmorland is an area of North West England and one of the 39 historic counties of England. It formed an administrative county from 1889 to 1974, after which the entirety of the county was absorbed into the new county of Cumbria.-Early history:...

. The nominate subspecies, Saxifraga stellaris subsp. stellaris is the northern subspecies, occurring from Canada to Russia, including the British Isles. The subspecies in the Alpide belt
Alpide belt
The Alpide belt is a mountain range which extends along the southern margin of Eurasia. Stretching from Java to Sumatra through the Himalayas, the Mediterranean, and out into the Atlantic, it includes the Alps, the Carpathians, the mountains of Asia Minor and Iran, the Hindu Kush, the Himalayas,...

 and other mountains in southern Europe is often called S. stellaris subsp. alpigena, but an older name has priority
Principle of Priority
thumb|270px|Boa manditraIn zoology, the scientific study of animals, the Principle of Priority is one of the guiding principles of the International Code of Zoological Nomenclature, defined by Article 23....

 – S. stellaris subsp. robusta. The name S. stellaris subsp. prolifera is used for plants from the south-eastern Alps
Southern Limestone Alps
The Southern Limestone Alps are the ranges of the Eastern Alps south of the Central Eastern Alps mainly located in northern Italy and the adjacent lands of Austria and Slovenia. The distinction from the Central Alps, where the higher peaks are located, is based on differences in geological...

 which have few flowers but produce bulbils along the stems.
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