{{short description|Species of flowering plant in the carnation family Caryophyllaceae}} {{speciesbox |image = Silene acaulis - Fjellsmelle.jpg |image_caption = ''Silene acaulis'' in [[Svalbard]], Norway |status = {{TNCStatus}} |status_system = TNC |status_ref = <ref name="NatureServe">{{cite web |last1=NatureServe |title=''Silene acaulis'' |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.130177/Silene_acaulis |access-date=19 January 2024 |location=Arlington, Virginia |date=2024}}</ref> |taxon = Silene acaulis |authority =([[L.]]) [[Nikolaus Joseph von Jacquin|Jacq.]] }}
'''''Silene acaulis''''', known as '''moss campion'''<ref name=BSBI07>{{BSBI 2007 |accessdate=2014-10-17 }}</ref> or '''cushion pink''', is a small [[wildflower]] that is common all over the high arctic and tundra and in high mountains of Eurasia and North America ([[Alps]], [[Carpathian Mountains|Carpathians]], southern [[Siberia]], [[Pyrenees]], [[British Isles]], [[Iceland]], [[Faroe Islands]], [[Greenland]], [[Rocky Mountains]]). It is an evergreen perennial [[flowering plant]] in the carnation family [[Caryophyllaceae]].
It is also called the '''compass plant''', since the flowers appear first on the south side of the cushion.<ref>{{Cite web | url=http://www.arcticsystem.no/en/arctic-inc/vegetation.html |title = The terrestrial vegetation in Svalbard}}</ref> ([[List of plants known as compass plant|Various other plants]] also have this name.)
== Description ==
Moss campion is a low, ground-hugging plant. It may seem densely matted and moss-like.<ref name=Weber>{{cite book |last=Weber |first=William A. |title=Colorado Flora. Western Slope |location=Boulder, CO |publisher=Colorado Associated University Press |date=1987 |isbn=9780870811678}}</ref><ref name=Revel>{{Cite journal| volume = 33| issue = 1| pages = 203–203| last = Revel| first = RichardD | url = http://pubs.aina.ucalgary.ca/arctic/Arctic33-1-203.pdf |title = A rare form of silene acaulis L.(moss campion) from british columbia| journal = Arctic| date = 1980}}</ref> The dense cushions are up to a foot or more in diameter. The bright green [[leaves]] are narrow, arising from the base of the plant. The dead leaves from the previous season persist for years, and pink flowers are borne singly on short stalks that may be up to {{Convert|1|in|cm|abbr=off|order=flip}} long, but are usually much shorter.
It usually has pink flowers, though very rarely they may be white.<ref name="Weber" /> The flowers are solitary and star-shaped. The flowers are female, male or hermaphrodite.<ref>{{cite journal |vauthors=Morris W, Doak D |date=June 1998 |title=Life history of the long-lived gynodioecious cushion plant ''Silene acaulis'' (Caryophyllaceae), inferred from size-based population projection matrices |journal=American Journal of Botany |volume=85 |issue=6 |pages=784–793 |doi=10.2307/2446413 |jstor=2446413 |pmid=21684962 |doi-access=free}}</ref> They are between {{Convert|6-12|mm|frac=4}} wide, with [[hermaphrodite flower]]s being larger than the female ones.<ref name="sex ratio">{{cite journal |last1=Alatalo |first1=Juha M. |last2=Molau |first2=Ulf |title=Effect of altitude on the sex ratio in populations of ''Silene acaulis'' (Caryophyllaceae) |journal=Nordic Journal of Botany |date=July 1995 |volume=15 |issue=3 |pages=251–256 |doi=10.1111/j.1756-1051.1995.tb00150.x}}</ref> Female flowers produce better quality seeds than hermaphrodites<ref>{{cite journal |last1=Shykoff |first1=Jacqui A. |title=Maintenance of gynodioecy in ''Silene acaulis'' (Caryophyllaceae): Stage specific fecundity and viability selection |journal=American Journal of Botany |date=1988 |volume=75 |issue=6 |pages=844–850 |doi=10.2307/2444003 |jstor=2444003 }}</ref> and male flowers produce better quality pollen than hermaphrodites.<ref>{{cite journal |last1=Alatalo |first1=Juha M. |last2=Molau |first2=Ulf |title=Pollen viability and limitation of seed production in a population of the circumpolar cushion plant, ''Silene acaulis'' (Caryophyllaceae) |journal=Nordic Journal of Botany |date=August 2001 |volume=21 |issue=4 |pages=365–372 |doi=10.1111/j.1756-1051.2001.tb00780.x}}</ref> The cushions can change the gender of their flowers between years.<ref>{{cite journal |last1=Alatalo |first1=Juha M. |title=Gender lability in trioecious ''Silene acaulis'' (Caryophyllaceae) |journal=Nordic Journal of Botany |date=June 1997 |volume=17 |issue=2 |pages=181–183 |doi=10.1111/j.1756-1051.1997.tb00307.x}}</ref> Gender frequencies change with altitude, the frequency of female flowers increasing with higher elevation.<ref name="sex ratio" /> They usually appear in June through August.<ref name="Alpine Plants of North America">Nicholls, Graham, and Rick Lupp. Alpine Plants of North America: an Encyclopedia of Mountain Flowers from the Rockies to Alaska. Portland: Timber, 2002.</ref> The flowers are held by a calyx which is rather firm and thick.<ref name="Land above the Trees">Zwinger, Ann, and Beatrice E. Willard. Land above the Trees: a Guide to American Alpine Tundra. Boulder, CO: Johnson, 1996.</ref>
The sepals are joined together into a tube that conceals the bases of the petals, which are entire. The 10 stamens and 3 styles extend well beyond the throat of the flower.<ref>Phillips, W (1999). Central Rocky Mountain Wildflowers: A Field Guide to Common Wildflowers, Shrubs, and Trees. Falcon Publishing, Inc.</ref> The stems and leaves are very sticky and viscid, which may discourage ants and beetles from climbing on the plant.<ref name="Land above the Trees" /> The variety ''exscapa'' has shorter flowering stems. The other variety ''subacaulescens,'' from Wyoming and Colorado, has pale pink flowers all summer.<ref name="Alpine Plants of North America" />
Plants in Colorado have been estimated to reach 75 to 100 years in age, and Alaskan plants may reach 300 years. The oldest known moss campion is 350 years old and has a diameter of two feet.<ref name="The Naturalist's Guide to the Southern Rockies">Benedict, Audrey D. The Naturalist's Guide to the Southern Rockies: Colorado, Southern Wyoming, and Northern New Mexico. Golden, CO: Fulcrum Pub., 2008.</ref>
==Gallery== {{gallery|mode=packed |Silene acaulis - Mosscampion.jpg|Bird's eye view, [[Svalbard]] |Mosscampion6.jpg|Scattered in Svalbard |Mosscampion5.jpg|Flower tops |Mosscampionclose.jpg|Close-up of flowers }}
==Distribution and habitat== [[Image:DistributionUSDA.png|thumb|[[USDA]] North American distribution of ''Silene acaulis (L.) Jacq.'']]
Moss campion is common all over the high arctic and the higher mountains of Eurasia and North America (south to the [[Alps]], [[Carpathian Mountains|Carpathians]], southern [[Siberia]], [[Pyrenees]], [[British Isles]], [[Iceland]], [[Faroe Islands]], [[Rocky Mountains]]). In the United States it inhabits Colorado, the [[Bighorn Mountains]] of Wyoming, the [[Wallowa Mountains]] of Oregon, the [[Olympic Mountains|Olympics]], the northern [[Cascade Range|Cascades]] of Washington, and Alaska.<ref name="Alpine Plants of North America"/>
Range: *USA (AK, AZ, CO, ID, ME, MT, NH, NM, NV, OR, UT, WA, WY) *CAN (AB, BC, LB, NF, NS, NT, NU, ON, QC, SK, YT) *DEN (GL), FRA (SPM) It inhabits [[Alpine fell-field|alpine fellfield]], on windswept rocky ridges and summits above treeline. It grows mainly in dry, gravelly localities, but also in damper places. With the cushions it produces its own, warmer climate with higher temperatures inside, when the sun shines.<ref name="The Naturalist's Guide to the Southern Rockies" />
==Ecology== In Maine it is possibly extirpated,<ref name="SIAC">{{cite web |title=''Silene acaulis'' (L.) Jacq. – moss campion |url=https://plants.usda.gov/java/profile?symbol=SIAC |url-status=live |archive-url=https://web.archive.org/web/20060511143245/http://plants.usda.gov/java/profile?symbol=SIAC |archive-date=2006-05-11 |website=PLANTS Profile |publisher=USDA}}</ref> and in New Hampshire ''Silene acaulis var. exscapa'' is threatened.<ref name="SIAC" />
Experimental warming has been shown to start flowering substantially earlier than control cushions experiencing ambient temperature. Both the male and female phases developed faster in the OTCs and capsules (fruits) matured earlier, and the cushions produced more mature seeds and had a higher seed/ovule ratio contributing to an overall positive reproductive response.<ref>{{cite journal |last1=Alatalo |first1=J.M. |last2=Totland |first2=Ø. |date=December 1997 |title=Response to simulated climatic change in an alpine and subarctic pollen‐risk strategist, ''Silene acaulis'' |journal=Global Change Biology |volume=3 |issue=S1 |pages=74–79 |bibcode=1997GCBio...3S..74A |doi=10.1111/j.1365-2486.1997.gcb133.x |s2cid=85793935}}</ref> However, a study on four populations across a latitudinal gradient in North America showed that southern populations of moss campion had lower survival and recruitment, but higher individual growth, rates than more northern populations. Furthermore, vital rates such as growth, survival, and fruits per area were shown to increase in moderately warmer years yet declined in the very warmest years, suggesting that a change in climate into warmer conditions or more frequent unusually warm summers may eventually lead to negative impacts.<ref>{{cite journal |last1=Doak |first1=Daniel F. |last2=Morris |first2=William F. |date=October 2010 |title=Demographic compensation and tipping points in climate-induced range shifts |journal=Nature |volume=467 |issue=7318 |pages=959–962 |bibcode=2010Natur.467..959D |doi=10.1038/nature09439 |pmid=20962844 |s2cid=4309240}}</ref> Another study showed that, while the short term responses were positive, they turned negative on medium-term, suggestion that moss campion may be at risk in future global warming.<ref>{{cite journal |last1=Alatalo |first1=Juha M. |last2=Little |first2=Chelsea J. |date=March 2014 |title=Simulated global change: contrasting short and medium term growth and reproductive responses of a common alpine/Arctic cushion plant to experimental warming and nutrient enhancement |journal=SpringerPlus |volume=3 |issue=1 |page=157 |doi=10.1186/2193-1801-3-157 |pmc=4000594 |pmid=24790813 |doi-access=free}}</ref> Projections produced under different climate scenarios suggest that ''S. acaulis'' will likely face climate-driven fast decline in suitable areas on the British Isles and across North America, and that upward and northward shifts to occupy new climatically suitable areas are improbable in the future.<ref>{{Cite journal |last1=Ferrarini |first1=Alessandro |last2=Alsafran |first2=Mohammed H. S. A. |last3=Dai |first3=Junhu |last4=Alatalo |first4=Juha M. |date=2019 |title=Improving niche projections of plant species under climate change: ''Silene acaulis'' on the British Isles as a case study |journal=Climate Dynamics |language=en |volume=52 |issue=3–4 |pages=1413–1423 |bibcode=2019ClDy...52.1413F |doi=10.1007/s00382-018-4200-9 |issn=0930-7575 |s2cid=133659980}}</ref><ref>{{Cite journal |last1=Ferrarini |first1=Alessandro |last2=Dai |first2=Junhu |last3=Bai |first3=Yang |last4=Alatalo |first4=Juha M. |date=2019 |title=Redefining the climate niche of plant species: A novel approach for realistic predictions of species distribution under climate change |journal=Science of the Total Environment |language=en |volume=671 |pages=1086–1093 |bibcode=2019ScTEn.671.1086F |doi=10.1016/j.scitotenv.2019.03.353 |issn=0048-9697 |s2cid=109744378}}</ref>
==Cultivation== The seeds should be sown early in the spring time. Put the seedlings into separate pots, and it is recommended to let them winter in the greenhouse for their first winter season. It is advised to plant them in the late spring or early summer because division takes place in the spring. They should be grown in well-drained soil with full sun. The climate can be cool.<ref name="Sileneacaulis">{{Cite web | url=http://www.pfaf.org/user/Plant.aspx?LatinName=Silene+acaulis | title=Silene acaulis Moss Campion PFAF Plant Database}}</ref>
== Toxicity == There is no listing that moss campion is toxic, though it does have saponins which, though toxic, are hard to absorb in the body. They can be broken down by thorough cooking. Its advised to not consume large amounts of this plant.
== Uses == The plant used to be used for children with [[colic]].<ref name="Sileneacaulis" /> The raw root skin plants were consumed as a vegetable in Iceland and in Arctic regions.<ref name="Sileneacaulis" />
==See also== *[[Flora of Svalbard]]
==References== {{Reflist|32em}}
==External links== *https://berryprairie.blogspot.com/2011/08/now-in-bloom-moss-campion.html *https://web.archive.org/web/20120118031459/http://www.arkive.org/moss-campion/silene-acaulis/#text=Description *http://www.northlandartsnatureimages.com/Nature/Flora-Fungii/15415805_879xmS/8/1371808898_dHVxchK#1371808898_dHVxchK *[https://web.archive.org/web/20120425022012/http://www.aplantshome.com/encyclopedia/pda_fc1a.html How to grow moss campion] *[http://www.sciencedirect.com/science/article/pii/000632077090008X Effects of Human Population on moss campion] {{Commons category|Silene acaulis|position=left}}
{{Taxonbar|from=Q1339103}}
[[Category:Cushion plants]] [[Category:Silene|acaulis]] [[Category:Alpine flora]] [[Category:Flora of the Arctic]] [[Category:Flora of Europe]] [[Category:Flora of Northern America]] [[Category:Flora of temperate Asia]] [[Category:Flora of the Alps]] [[Category:Flora of the Carpathians]]