Carex arctogena

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Carex arctogena
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Cyperaceae
Genus: Carex
Species:
C. arctogena
Binomial name
Carex arctogena
Harry Sm., 1940

Carex arctogena is a member of the sedge family (Cyperaceae) which grows in high alpine areas. It is one of the few "bipolar" species; it has populations in Greenland, Scandinavia, Russia, Canada and southern South America. [1] Plants in the far north and south appear to be genetically identical, having taken advantage of a similar niches on opposite ends of the globe.

Contents

Carex arctogena has often been confused with the closely related Carex capitata . They were classified as one species until Harry Smith distinguished the differences between them 1940. [2] [3] Defining morphological characteristics of this species include: toothed scales which cover the female reproductive parts of the inflorescence, a larger seed relative to the size of the female reproductive sac (perigynia) and round perigynia which quickly taper towards the apex. It produces a single spike on each stem and has long elongated leaves which are characteristic for the genus Carex.

Description

C. arctogena has short rhizomes which grow new shoots and roots, allowing it to grow in a cespitose (tufted or turf-like) manner. This means that it can be found growing in dense tufts amongst its habitat. [4] [5]

This species produces vegetative shoots which become leaves; these are made up from a leaf sheath covering a culm. These will grow to be 1 mm wide and have parallel veins running through the sheath. Sedges' reproductive shoots are where their inflorescences grow. [4] Specimens are typically between 10 and 30 cm tall but tend toward the smaller sizes as the sister species, C. capitata, is usually taller. [4]

A spike will be made up from many florets. Basal florets consist of a pair of brown glumes (two sterile bracts) which subtend the perigynia. [6] In C. arctogena the glumes are brown and significantly smaller than those of its sister species. [4]

Within a spike there will numerous perigynia; these perigynia are membranes which enclose female flowers and fruits. Each perigynia will be on average 1.7–2.7 mm long and 1.2–1.7 mm wide, forming a bottle shape towards the open apex. [5] In Carex this is termed a "beak" and can be seen drastically tapering in C. arctogena compared to the perigynia's otherwise reasonably rounded main body. [5]

In Cyperaceae the perianth (sepals and petals) is often reduced or absent, which results in visible reproductive organs. [7] In C. arctogena the perianth is absent meaning that only the style or stigma may protrude from the narrowed opening. [7] The female flowers have two long thin stigmas which can appear red or brown. [5] The ovary can be defined as superior (the ovary lies above the point of attachment for sepals, petals and stamens. [8] [6]

C. arctogena is monoecious, meaning that both pistilate (female) and staminate (male) flowers occur on the same spike. This makes the whole sedge androgynous. The female flowers (multiple spikelets) are arranged in a spherical shape around the centre of the spike, but nonetheless still point upwards no matter how marginally. Male flowers are sparsely arranged at the apex of the inflorescence, creating a conical projection at the top of the spike. [7] Typically these characteristics can segregate C. arctogena from C. capitata as the spikelets will not be so erect and may point outwards, creating a less overall conical shape of the inflorescence.

A typical characteristic of C. arctogena are the pistilate scales on the perigynium. These cover almost the whole perigynia body but stop before it tapers at the apex. These can be seen under a microscope and appear white, with toothed margins. [4] In C. capitata, the pistilate scales will be much shorter than the perigynia and will not appear toothed.

The fruit produced by C. arctogena is classed as an achene, a dry seed which has a thin wall. [6] These characteristics make the seed light and enable it to be dispersed by wind. The presence of two stigmas equates to the fruit produced having two sides and being classified as lenticular. [4] In this species the achene is larger relative to the perigynia, meaning that it will almost completely fill this area. Whereas in C. capitata, the achene is considerably smaller than the area of the perigynium. [5]

Etymology

The generic name, Carex , is the Latin word for sedge. It comes from the Greek word kairo which means "to cut", this refers to the long narrow leaves in which some species have sharp edges. [9] The specific name arctogena is derived from the species' Arctic distribution.

Habitat and ecology

This species has a bipolar distribution which means it can be found in both the Northern and Southern Hemispheres. The habitats are usually alpine areas at high altitude. Within its northern locality in Fremont County[ clarification needed ] samples have been found on alpine summits at 2,590–370 metres (8,500–1,200 ft). [5] Whereas, within the Arctic climate of Greenland specimens have been found at maximum altitudes of 250 metres (820 ft). [10]

Primarily this species prefers poor, lime soils and has been known to grow in serpentine soils; these contain higher than average amounts of nickel, iron, cobalt and chromium. [11] High alpine areas have large amounts of surface runoff from snowfields, meaning that the soil quality may be poor. [3] Many herbarium specimens have been found on heathlands and grasslands located on hilltops. This creates a niche habitat for species which prefer little soil nutrients and harsh winds. [11] Due to it being an alpine plant, it is rarely found below the tree line, meaning it grows only in forested areas.[ clarification needed ]

The habitat of C. arctogena and C. capitata rarely overlap. C. arctogena grows at higher elevations and prefers moist calcareous soils, not overshadowed by dense forest cover.[ clarification needed ]

In the Southern Hemisphere C. arctogena occupies the same ecological niche but its distribution is smaller because there are fewer optimal alpine areas.

Distribution

Carex arctogena has a bipolar distribution across Arctic regions in the Northern Hemisphere and temperate regions in the Southern Hemisphere. This means that it can be found at high latitudes north of 55 ˚N and south of 52 ˚S. [1]

Within this range there are populations in the Northern Hemisphere that include:

In the Southern Hemisphere:

A study revealed haplotypes in C. arctogena which also occur in C. capitata, which is only present in the Northern Hemisphere. [1] From this we can assume that C. arcotgena was originally distributed in the Northern Hemisphere and more recently established populations in the south.

Taxonomy and systematics

In 1940 Harry Smith was the first to propose that C. capitata was actually two species. He described differences in populations that he observed in Sweden, noticing small brown inflorescences compared to that of the larger green inflorescences of C. capitata. He created a set of characteristics that could be used to distinguish them. Smith gathered and analysed samples from museums, and was able to separate them into C. arctogena (a new species) or C. capitata as described by Carl Linnaeus. [3]

Today the name Carex arctogena Harry Sm. is the accepted name for this species. Although during the last century many new taxonomic classifications were proposed. In 1944 Hiitonen[ clarification needed ] proposed that C. arctogena should be classified as Carex capitata subsp. arctogena. This was also suggested by Tyge W. Böcher in 1952 but that has not been accepted by taxonomists. In 1949 it was classified by Raymond as: Carex capitata f. arctogena, and in 1958 Eric Hultén proposed C. arctogena be classified as a variety of C. capitata. None of these were widely accepted and today we have genetic evidence that these are two distinct species. Genetic analyses has verified that C. arctogena and C. capitata share a common origin. C. arctogena likely diverged recently as there little genetic variation within it, not even between specimens from different hemispheres. [11]

Type specimens are located at herbariums in northern Europe, New Hampshire, Argentina and Labrador.

Bipolar distribution

Only 30 plant species are known to have a bipolar distribution, a large proportion of which belong to the family Cyperaceae. [12] It has been hypothesised that C. arctogena has been dispersed either by anthropomorphic introduction or by migratory birds. The seeds within this species have been found to contain silica deposits in the pericarp, this can help to make the seeds tougher. [13]

Related Research Articles

<i>Carex</i> Genus of flowering plants

Carex is a vast genus of more than 2,000 species of grass-like plants in the family Cyperaceae, commonly known as sedges. Other members of the family Cyperaceae are also called sedges, however those of genus Carex may be called true sedges, and it is the most species-rich genus in the family. The study of Carex is known as caricology.

<i>Rhynchospora alba</i> Species of plant

Rhynchospora alba, the white beak-sedge, is a plant in the sedge family, Cyperaceae. It is a tufted herbaceous perennial around 50 cm tall, with white inflorescences that flower in August. The fruit of the sedge is a small achene with a characteristic beak-like cap. It is dispersed by wind or falls by gravity, leading to individuals existing in tight clumps. The species favours wet, acidic and nutrient poor soils, thriving in Sphagnum-dominated bogs, but also peaty grasslands. As such it is often used as a positive indicator for bog and mire ecosystem health.

<i>Carex pauciflora</i> Species of grass-like plant

Carex pauciflora, known as few-flowered sedge, is a perennial species of sedge in the family Cyperaceae native to bogs and fens in cool temperate, subarctic, and mountainous regions of the Northern Hemisphere. The specific epithet pauciflora refers to the Latin term for 'few flowered'.

<i>Carex aquatilis</i> Species of plant

Carex aquatilis is a species of sedge known as water sedge and leafy tussock sedge. It has a circumboreal distribution, occurring throughout the northern reaches of the Northern Hemisphere. It grows in many types of mountainous and arctic habitat, including temperate coniferous forest, alpine meadows, tundra, and wetlands.

<i>Carex capitata</i> Species of grass-like plant

Carex capitata is a species of sedge known by the common name capitate sedge. It has a circumboreal distribution including Norway, Russia, Siberia, Alaska, Canada and Greenland. Growing in wet places in boreal forests and mountain meadows in alpine climates.

<i>Carex hystericina</i> Species of plant

Carex hystericina is a species of sedge known by the common names bottlebrush sedge and porcupine sedge. It is native to much of North America including most of southern Canada and most of the United States. It grows in wet habitat such as wetlands and riverbanks, especially on calcareous soils. In the right conditions it can become very abundant and even weedy. This sedge produces dense or loose clumps of triangular stems up to a meter tall from short rhizomes. The inflorescence is several centimeters long and is accompanied by a bract which is longer than the spikes. The fruits are coated in perigynia with pointed, toothed tips. It is highly recommend for sedge meadow restorations.

<span class="mw-page-title-main">Perigynium</span> Structure that encloses the ovary in Carex

In botany, a perigynium, also referred to as a utricle, typically refers to a sac that surrounds the achene of plants in the genus Carex (Cyperaceae). The perigynium is a modified prophyll, also known as a glume, which is tissue of leaf origin that encloses the dry, one-seeded achene.

Carex klamathensis is a rare species of sedge known by the common name Klamath sedge. It is known from 15 or fewer populations in southern Oregon and three populations in the Klamath Region of northern California. It was described to science only in 2007. Its habitat includes fens and other wet habitat, on serpentine soils. It was discovered independently by botanists Peter Zika and Lawrence Janeway.

<i>Carex binervis</i> European species of sedge with an Atlantic distribution

Carex binervis, the green-ribbed sedge, is a European species of sedge with an Atlantic distribution. It is found from Fennoscandia to the Iberian Peninsula, and occurs in heaths, moorland and other damp, acidic environments. It typically grows to a height of 15–120 cm (6–50 in), and has inflorescences comprising one male and several female spikes, each up to 45 mm (1.8 in) long. The utricles have two conspicuous green veins, which give rise to both the scientific name and the common name of the species. In the vegetative state, it closely resembles C. bigelowii, a species that usually grows at higher altitude. C. binervis was first described by James Edward Smith in 1800, and is classified in Carex sect. Spirostachyae; several hybrids with other Carex species are known.

<i>Carex pilulifera</i> Species of grass-like plant

Carex pilulifera, the pill sedge, is a European species of sedge found in acid heaths, woods and grassland from Macaronesia to Scandinavia. It grows up to 30 cm (12 in) tall, with 2–4 female spikes and 1 male spike in an inflorescence. These stalks bend as the seeds ripen, and the seeds are collected and dispersed by ants of the species Myrmica ruginodis.

<i>Carex bigelowii</i> Species of grass-like flowering plant

Carex bigelowii is a species of sedge known by the common names Bigelow's sedge, Gwanmo sedge, and stiff sedge. It has an Arctic–alpine distribution in Eurasia and North America, and grows up to 50 centimetres (20 in) tall in a variety of habitats.

<i>Carex vaginata</i> Species of grass-like plant

Carex vaginata is a species of sedge known by the common name sheathed sedge.

<i>Carex distans</i> Species of plant

Carex distans, commonly known as distant sedge, is a plant species in the sedge family, Cyperaceae. It is native to Europe and North Africa. It is part of a complex of similar species that occur across Eurasia. Its relatives include Carex diluta of central Asia, which has also introduced to North America in Montana. C. distans has been introduced to US states including Maryland and Pennsylvania. More recently, it was found in Oregon. There is a report from Victoria, Australia as well.

<i>Carex lacustris</i> Species of grass-like plant

Carex lacustris, known as lake sedge, is a tufted grass-like perennial of the sedge family (Cyperaceae), native to southern Canada and the northern United States. C. lacustris us an herbaceous surface-piercing plant that grows in water up to 50 cm (1.6 ft) deep, and grows 50–150 cm (1.6–4.9 ft) tall. It grows well in marshes and swampy woods of the boreal forest, along river and lake shores, in ditches, marshes, swamps, and other wetland habitat. It grows on muck, sedge peat, wet sand or silt, in filtered or full sunlight.

<i>Carex eburnea</i> Species of grass-like plant

Carex eburnea, known as ivory sedge, ebony sedge, and bristleleaf or bristle-leaved sedge, is a small and slender sedge native to North America, from Alaska and Newfoundland south to central Mexico.

<i>Carex rosea</i> Species of sedge

Carex rosea, the rosy sedge, is a flowering plant and part of the family Cyperaceae. Synonyms for Carex rosea include Carex concoluta, and Carex flaccidula. It is native to central and eastern North America and it exists in wet to dry soils. Carex rosea can be found in shores of streams and bottomlands, as well as ponds. It is known to have good adaptations to dry-shade locations. It is an evergreen plant which is easy to grow.

<i>Carex brevior</i> Species of grass-like plant

Carex brevior, known as shortbeak sedge and plains oval sedge, is a species of sedge native to North America. The specific epithet brevior means "shorter" in Latin.

<i>Carex juniperorum</i> Species of grass-like plant

Carex juniperorum, the juniper sedge, is a perennial flowering plant native to North America, first described by botanist William J. Crins in 1993. C. juniperorum is in the Cyperaceae (sedge) family, and is closely related to C. jamesii and C. willdenowii. It is commonly called juniper sedge as it is often seen growing in areas with red cedar, though the presence of cedar is not necessarily a requirement for it to grow.

<i>Carex muehlenbergii</i> Species of grass-like plant

Carex muehlenbergii is a species of flowering plant, it is a type of sedge. It is a grass-like plant in the family Cyperaceae. Its common names include sand sedge, Muhlenberg's sedge.

Carex ledongensis is a species of sedge in the family Cyperaceae. Found in the tropical monsoon rainforests of Hainan Island, China, it was described as a new species in 2020. It shares similarities with the species Carex pseudotristachya but exhibits distinct characteristics that set it apart.

References

  1. 1 2 3 Villaverde, Tamara; Escudero, Marcial; Martín-Bravo, Santiago; Bruederle, Leo; Garcés, Modesto & Starr, Julian (22 April 2015). "Direct long‐distance dispersal best explains the bipolar distribution of Carex arctogena (Carex sect. Capituligerae, Cyperaceae)". Journal of Biogeography. 42 (8): 1514–1525. doi:10.1111/jbi.12521. hdl: 10261/125311 . S2CID   86795797.
  2. 1 2 "Carex arctogena Harry Sm". Plants of the World Online. Kew Science. 2019. Retrieved 9 October 2019.
  3. 1 2 3 Smith, H. (1940). "Carex arctogena nova species". Acta Phytogeographica Suecica. 13: 191–200.
  4. 1 2 3 4 5 6 Wilson, Barbara L.; Brainerd, Richard E.; Lytjen, Danna; Newhouse, Bruce & Otting, Nick (2014). Field Guide to the Sedges of the Pacific Northwest (2nd ed.). Oregon State University Press. pp. 14–125. ISBN   978-0-87071-728-4.
  5. 1 2 3 4 5 6 Hermann, Frederick J. (1970). Manual of the Carices of the Rocky Mountains and Colorado Basin. Forest Service, U. S. Department of Agriculture. pp. 16, 40–41.
  6. 1 2 3 Beentje, Henk (2016). The Kew Plant Glossary. Illustrated by Juliet Williamson (2nd ed.). University of Chicago Press. ISBN   9781842466049.
  7. 1 2 3 Böcher, Tyge W.; Holmen, Kjeld; Jakobsen, Knud; Frederiksen, I.; Elkington, T.; Lewis, M. & Flora, G. (1968). The Flora of Greenland. P. Haase. pp. 218–231.
  8. ↑ Simpson, Michael G. (2010). Plant Systematics. Elsevier Science. pp. 249–253. ISBN   9780123743800.
  9. ↑ Hyam, Roger & Pankhurst, Richard J. (1995). Plants and Their Names. Oxford University Press. p. 90. ISBN   978-0198661894.
  10. ↑ Halliday, Geoffrey & Corner, R. W. N. (2019). A Flora of the East Greenland Central Fjord region 70°N-77°N. Trollius Publications. p. 220. ISBN   9780953971879.
  11. 1 2 3 Reinhammar, Lars-Gunnar (July 1999). "Allozyme differentiation between the lowland Carex capitata and the alpine Carex arctogena (Cyperaceae) in Scandinavia". Biological Journal of the Linnean Society. 67 (3): 377–389. doi: 10.1111/j.1095-8312.1999.tb01940.x .
  12. ↑ Villaverde, Tamara; Escudero, Marcial; Martín‐Bravo, Santiago; Jiménez‐Mejías, Pedro; Sanmartín, Isabel; Vargas, Pablo & Luceño, Modesto (November 2017). "Bipolar distributions in vascular plants: A review". American Journal of Botany. 104 (11): 1680–1694. doi: 10.3732/ajb.1700159 . PMID   29167157.
  13. ↑ Graven, Peter; De Koster, Chris G.; Boon, Jaap J. & Bouman, Ferry (1996). "Structure and macromolecular composition of the seed coat of the Musaceae". Annals of Botany. 77 (2): 105–122. doi: 10.1006/anbo.1996.0013 ..
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