Invasive Species Compendium

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Datasheet

Carex kobomugi
(Asiatic sand sedge)

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Datasheet

Carex kobomugi (Asiatic sand sedge)

Summary

  • Last modified
  • 25 September 2018
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Carex kobomugi
  • Preferred Common Name
  • Asiatic sand sedge
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Monocotyledonae
  • Summary of Invasiveness
  • Carex kobomugi, commonly known as Asiatic sand sedge, is locally dominant in sand dunes in its native range in Taiwan, Korea, Japan, China and eastern Russia. Accidentally introduced to coastal areas of northea...

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Pictures

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PictureTitleCaptionCopyright
Carex kobomugi (Asiatic sand sedge); invasive habit. USA. June, 2005.
TitleInvasive habit
CaptionCarex kobomugi (Asiatic sand sedge); invasive habit. USA. June, 2005.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); invasive habit. USA. June, 2005.
Invasive habitCarex kobomugi (Asiatic sand sedge); invasive habit. USA. June, 2005.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); invasive habit, winter state. USA. April, 2007.
TitleInvasive habit
CaptionCarex kobomugi (Asiatic sand sedge); invasive habit, winter state. USA. April, 2007.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); invasive habit, winter state. USA. April, 2007.
Invasive habitCarex kobomugi (Asiatic sand sedge); invasive habit, winter state. USA. April, 2007.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); habit. USA. June, 2002.
TitleHabit
CaptionCarex kobomugi (Asiatic sand sedge); habit. USA. June, 2002.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); habit. USA. June, 2002.
HabitCarex kobomugi (Asiatic sand sedge); habit. USA. June, 2002.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); habit, winter state. USA.
TitleHabit
CaptionCarex kobomugi (Asiatic sand sedge); habit, winter state. USA.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); habit, winter state. USA.
HabitCarex kobomugi (Asiatic sand sedge); habit, winter state. USA.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); flowering habit. USA.
TitleFlowering habit
CaptionCarex kobomugi (Asiatic sand sedge); flowering habit. USA.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); flowering habit. USA.
Flowering habitCarex kobomugi (Asiatic sand sedge); flowering habit. USA.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); developing seed heads. USA. June, 2005.
TitleSeed heads
CaptionCarex kobomugi (Asiatic sand sedge); developing seed heads. USA. June, 2005.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); developing seed heads. USA. June, 2005.
Seed headsCarex kobomugi (Asiatic sand sedge); developing seed heads. USA. June, 2005.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); pulled plants, showing root system. USA. June, 2005.
TitlePulled plants
CaptionCarex kobomugi (Asiatic sand sedge); pulled plants, showing root system. USA. June, 2005.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); pulled plants, showing root system. USA. June, 2005.
Pulled plantsCarex kobomugi (Asiatic sand sedge); pulled plants, showing root system. USA. June, 2005.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); ripening seed head (a) and flower spike (b). USA.
TitleSeed head and flower spike
CaptionCarex kobomugi (Asiatic sand sedge); ripening seed head (a) and flower spike (b). USA.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); ripening seed head (a) and flower spike (b). USA.
Seed head and flower spikeCarex kobomugi (Asiatic sand sedge); ripening seed head (a) and flower spike (b). USA.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); close view of flower spike. USA
TitleFlower spike
CaptionCarex kobomugi (Asiatic sand sedge); close view of flower spike. USA
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); close view of flower spike. USA
Flower spikeCarex kobomugi (Asiatic sand sedge); close view of flower spike. USA©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); close view of developing seed head. USA.
TitleSeed head
CaptionCarex kobomugi (Asiatic sand sedge); close view of developing seed head. USA.
Copyright©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US
Carex kobomugi (Asiatic sand sedge); close view of developing seed head. USA.
Seed headCarex kobomugi (Asiatic sand sedge); close view of developing seed head. USA.©Leslie J. Mehrhoff/University of Connecticut/Bugwood.org - CC BY 3.0 US

Identity

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Preferred Scientific Name

  • Carex kobomugi Ohwi

Preferred Common Name

  • Asiatic sand sedge

Other Scientific Names

  • Carex macrocephala var. kobomugi (Ohwi) Miyabe & Kudo
  • Carex macrocephala var. longibracteata Oliver
  • Vignea kobomugi (Ohwi) Soják

International Common Names

  • English: Japanese sedge; sea isle Japanese sedge
  • Chinese: shai cao

Summary of Invasiveness

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Carex kobomugi, commonly known as Asiatic sand sedge, is locally dominant in sand dunes in its native range in Taiwan, Korea, Japan, China and eastern Russia. Accidentally introduced to coastal areas of northeast USA prior to 1929, a cultivar was developed and promoted as a sand dune stabilizer until the 1980s. Now it is established from New York to North Carolina. It is viewed as a harmful, exponentially spreading, robust, mat-forming, and dominant perennial invader. It spreads locally via deep (up to 1.5 m) rhizomes, and over larger distances via buoyant seeds and (more commonly) rafting fragments. Rhizomes often survive targeted treatments which makes control difficult. It has caused declines of 50-75% abundance of several native dune plants and has reduced species richness. It impacts rare species, including piping plovers (Charadrius melodus), hairy-necked tiger beetle (Cicindela hirticollis) and seabeach amaranth (Amaranthus pumilus) through direct competition, reduction of habitat or food availability. Carex kobomugi is banned from sale and distribution in Massachusetts and Connecticut, USA.

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Monocotyledonae
  •                     Order: Cyperales
  •                         Family: Cyperaceae
  •                             Genus: Carex
  •                                 Species: Carex kobomugi

Notes on Taxonomy and Nomenclature

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Carex kobomugi was once considered a variety of Carex macrocephala which is native to the coastal areas on the east and west sides of the Northern Pacific Rim (Russian Far East, Japan and the West Coast of North America from Oregon to Alaska). Ohwi gave C. kobomugi species status in 1930 (Flora of North America Editorial Committee, 1993).

C. kobomugi occurs in Taiwan, Japan, Korea and Russia (Wootton, 2005; Wootton et al., 2007). Phylogenetic evidence initially seemed to indicate the paraphyly of C. macrocephala with respect to C. kobomugi, but the divergence time estimates under a coalescent model for the two clades of C. macrocephala from either side of the Pacific (Asia and North America) suggested they shared a more recent common ancestor than either of the clades shared with C. kobomugi (King et al., 2009).

Initial concerns about the two species hybridizing were not born out in New Jersey, USA, when genetic tests revealed no hybrids (Wootton, 2007; Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014). 

Description

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The Flora of North America Editorial Committee (1993) gives the following description for C. kobomugi:

Plants usually not cespitose, rhizomatous. Culms brown at base. Leaves: basal sheaths fibrous; sheath fronts membranous; blades V-shaped in cross section when young, widest leaves 4-8 mm wide, glabrous. Inflorescences paniculate, with 20+ spikes, ovoid or oblong capitate, occasionally with proximal 1-2 spikes separated, sessile; proximal bracts leaflike or threadlike, sheathless; spikes staminate, pistillate, or androgynous, sessile, without prophylls. Proximal pistillate scales with apex awned. Perigynia ascending or at length spreading, veined on both faces, short-stipitate, narrowly ovate, thickly plano-convex in cross section, base tapering or rounded, with spongy tissue, margins serrulate-winged, apex tapering to beak, glabrous; beak with abaxial suture, margins entire, apex bidentate. Stigmas 3. Achenes rounded-trigonous, smaller than bodies of perigynia; style deciduous.

Plant Type

Top of page Grass / sedge
Herbaceous
Perennial
Seed propagated
Vegetatively propagated

Distribution

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C. kobomugi is native to East Asia and has been introduced to northeast USA. Accounts of C. macrocephala in China are considered to refer to C. kobomugi (Flora of North America Editorial Committee, 1993; Flora of China Editorial Committee, 2014). Unmentioned in the Flora of China (Flora of China Editorial Committee, 2014) is the plant’s occurrence in Tibet; it is not specifically discussed but it was probably introduced there for mining tailings reclamation (Zhang et al., 2010).

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

ChinaPresentPresent based on regional distribution.
-AnhuiPresentNative Not invasive Flora of China Editorial Committee, 2014
-HebeiPresentNative Not invasive Flora of China Editorial Committee, 2014
-HeilongjiangPresentNative Not invasive Flora of China Editorial Committee, 2014
-JiangsuPresentNative Not invasive Hu et al., 2013; Flora of China Editorial Committee, 2014
-LiaoningPresentNative Not invasive Flora of China Editorial Committee, 2014
-ShandongPresentNative Not invasive Flora of China Editorial Committee, 2014
-ZhejiangPresentNative Not invasive Flora of China Editorial Committee, 2014
JapanPresentNativeIshikawa and Kachi, 1998; Flora of China Editorial Committee, 2014Honshu and other islands
Korea, DPRPresentNativeFlora of China Editorial Committee, 2014
TaiwanPresentNative Not invasive Flora of China Editorial Committee, 2014

North America

USAPresentPresent based on regional distribution.
-DelawareLocalisedIntroduced Invasive Govaerts et al., 2007; EDDMapS, 2015
-MarylandLocalisedIntroduced Invasive EDDMapS, 2015; PCA Alien Plant Working Group, 2015
-MassachusettsIntroduced, establishment uncertainIntroduced Invasive EDDMapS, 2015Barnstable County
-New JerseyWidespreadIntroducedearly 1900s Invasive Wootton et al., 2005Long established and spreading
-New YorkLocalisedIntroduced Invasive Lamont and Young, 2014; EDDMapS, 2015
-North CarolinaLocalisedIntroduced Invasive Weakley, 2012Planted as a stabilizer of coastal dunes. Currituck
-OregonPresentIntroducedearly 1900sCarex Working Group, 2014; Consortium of Pacific Northwest Herbaria, 2015
-Rhode IslandLocalisedIntroduced Invasive Enser, 2006; EDDMapS, 2015
-VirginiaLocalisedIntroduced1941 Invasive Boule, 1979; Standley, 1983; EDDMapS, 2015Accomack, Chesapeake, Northampton, Virginia Beach
-WashingtonLocalisedIntroduced2005 Invasive Consortium of Pacific Northwest Herbaria, 2015

Europe

Russian FederationPresentPresent based on regional distribution.
-Russian Far EastPresentNative Not invasive Govaerts et al., 2007Sakhalin, Primorye

History of Introduction and Spread

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C. kobomugi was first reported from Portland, Oregon, USA, in 1907 at a sand ballast site (Carex Working Group, 2014; Consortium of Pacific Northwest Herbaria, 2015). It was accidentally introduced to northeastern USA (first collected in New Jersey) in the 1920s, and also to Virginia in 1941 (Standley, 1983) suggesting more than one introduction event on the east coast of USA (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014). The first speculation was that it was used as packing material, but this was later considered unlikely given that the plant is not so common in its native range, at least relative to other plants (Wootton, 2007). The current suggested mode of introduction is via water ballast or sand ballast from ships. Support for this pathway of introduction was found when C. kobomugi was collected from Cape Disappointment State Park in Washington, USA, in 2005 just north of the Columbia River and downstream from Portland, Oregon populations (Consortium of Pacific Northwest Herbaria, 2015).

Early accounts of its competitive ability in New Jersey, USA, were farsighted (Small, 1954) and remain accurate 50 years later (Wootton et al., 2005), but unfortunately its use as a dune stabilizer was promoted. In the 1960s a cultivar of C. kobomugi was developed as tread-resistant sand dune stabilizer by government officials (Shisler et al., 1987).

Most of C. kobomugi’s long distance spread between Massachusetts and North Carolina, USA, can probably be attributed to human-assisted dispersal, since all individuals are genetically identical in New Jersey (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014). Records at new sites continue to establish, and in some monitored areas (New Jersey) C. kobomugi has increased in extent by 2-7 orders of magnitude over two decades (Wootton et al., 2005), a trend that has undoubtedly continued (after Hurricane Sandy in 2012, willingness to control the plant has reduced due to concerns about loss of stabilization during restoration). 

Introductions

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Introduced toIntroduced fromYearReasonIntroduced byEstablished in wild throughReferencesNotes
Natural reproductionContinuous restocking
Delaware New Jersey 1950-1990 Yes No EDDMapS (2015) Some spread undoubtedly natural but species probably introduced for dune stabilization
Maryland New Jersey 1950-1990 Yes No EDDMapS (2015) Some spread undoubtedly natural but species probably introduced for dune stabilization
New Jersey Asia 1929 Yes No Wootton et al. (2005)
New York New Jersey 2012 Yes No Lamont and Young (2014)
North Carolina New Jersey 1950-1990 Yes No Weakley (2012) Some spread undoubtedly natural but species probably introduced for dune stabilization
Oregon Asia 1907 Yes No Carex Working Group (2014); Consortium of Pacific Northwest Herbaria (2015); Consortium of Pacific Northwest Herbaria (CNPWH) (2015) Mostly found in port authority land so far, largely an urban environment
Rhode Island New Jersey 1950-1990 Yes No EDDMapS (2015) Some spread undoubtedly natural but species probably introduced for dune stabilization
Virginia Asia 1941 No Yes Standley (1983)

Risk of Introduction

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There is a distinct risk that C. kobomugi could be planted in new areas based on its reported utility as a dune stabilizer. Plant fragments and seeds could also be unintentionally transported as a contaminant of sand or water. 

Habitat

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In its naturalized range C. kobomugi is found mostly on sandy beaches along sea coasts, bays and inlets while in its native range it is commonly found on ocean beaches but it is also known from sandy freshwater river and lake margins (Small, 1954; Kim, 2005; Wootton, 2007; Hayasaka et al., 2012; Carex Working Group, 2014; Flora of China Editorial Committee, 2014). It thrives in the back-dune and inter-swale areas (Wootton, 2007).

Habitat List

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CategoryHabitatPresenceStatus
Freshwater
Lakes Principal habitat Natural
Rivers / streams Principal habitat Natural
Littoral
Coastal areas Principal habitat Harmful (pest or invasive)
Coastal areas Principal habitat Natural
Coastal areas Principal habitat Productive/non-natural
Coastal dunes Principal habitat Harmful (pest or invasive)
Coastal dunes Principal habitat Natural
Coastal dunes Principal habitat Productive/non-natural

Host Plants and Other Plants Affected

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Plant nameFamilyContext
Amaranthus pumilus (seabeach amaranth)AmaranthaceaeOther
Ammophila breviligulataPoaceaeOther
Artemisia (wormwoods)AsteraceaeOther
Solidago sempervirensAsteraceaeOther
Spartina patens (saltmeadow cordgrass)PoaceaeOther

Biology and Ecology

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Genetics

Chromosome number 2n=84 (Flora of China Editorial Committee, 2014) but another source gives it as 2n=88 with a genome size of 221 Mbp (Roalson, 2008).

In its native range clonal spread via rhizomes was shown to be extensive but genotyping showed that seed reproduction does occur too (Ohsako, 2010). Early results in its introduced range suggest that a single genotype is responsible for all the known infestations in New Jersey, USA (and probably many of the introduced populations in the northeastern USA since they were spread intentionally); this raises the possibility that all the spread is via stem fragments; if seed is involved the seed must be apomictic (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014). It has been reported that populations in Asia exhibit the typical range of variation (King and Roalson, 2009a). Microsatellite markers have been developed that would allow further study of the population (King and Roalson, 2009b).

In its introduced range, genotyping revealed that all plants in a population of co-occurring C. kobomugi and C. macrocephala were distinct, none being hybrids (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014). This means earlier concerns about the possibility of hybrids forming between these two closely related species (Wootton, 2007) have not been borne out so far.

Reproductive Biology

C. kobomugi exhibits paradioecy – individuals can have different sexes on different shoots, and some spikes are also androgynous. The seeds have been regarded as not very good at germinating, but germination appears to only occur when special conditions are met; germination rates of 60% were obtained at temperatures of 30-35°C (3% at 15°C), only scarified seeds germinated in the lab, and rates were highest from spring to summer (Ishikawa et al., 1993).

Ishikawa et al. (1993) found that chilling did not remove dormancy in the lab but in the field it did and leads to spring and summer germination, possibly because the action of fluctuating temperatures and moisture on the seed coat broke the seed-coat induced dormancy. However, the ‘sandpaper’ effect (germination after scarification of seeds) was not observed to contribute to removal of dormancy. Furthermore they showed that in the field most seeds germinated at or below 10 cm in depth, where moisture is generally constant.

Physiology and Phenology

In North Carolina, USA, C. kobomugi’s short stout culms, and its terminal, headlike, dioecious inflorescences are present from March to July (Weakley, 2012). Flowering periods further north should be similar but may start and end a little later in the spring and summer.

Seeds germinate in spring and summer; fruit are produced in summer.

Carex kobomugi is very tolerant to sand blasting and high amounts of salt spray (Yura and Ogura, 2006), which often occur on the forefront of a dune.

Carex kobomugi rhizomes are not only deeper than American beachgrass (Ammophila breviligulata), but also have a greater amount of internodes (Small 1954). This may be part of the reason why C. kobomugi can spread faster than A. breviligulata.

Associations

Zhang et al. (2010) reported symbiosis with arbuscular mycorrhizal (AM) fungi, and Edelhauser (2011) also found C. kobomugi in New Jersey, USA, to be mycorrhizal. Matsuoka et al. (2013) did not find symbiotic fungi, but rather bacteria; Bacillus sp., Streptomyces luteogriseus, and Pseudomonas fluorescens were found to contribute to iron and phosphorous uptake. 

Khan et al. (2009) found that C. kobomugi roots contained nine different endophytic fungi, five of which produced gibberellins, which promote shoot elongation. This may promote rapid growth.

Climate

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ClimateStatusDescriptionRemark
Cf - Warm temperate climate, wet all year Tolerated Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year
Cs - Warm temperate climate with dry summer Tolerated Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers

Latitude/Altitude Ranges

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Latitude North (°N)Latitude South (°S)Altitude Lower (m)Altitude Upper (m)
46 23

Soil Tolerances

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Soil drainage

  • free

Soil texture

  • light

Notes on Natural Enemies

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Rabbits are known to graze the closely related C. macrocephala but C. kobomugi appears to be resistant to browsing (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014).

Means of Movement and Dispersal

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Natural Dispersal

C. kobomugi is very effective at regenerating from fragments and can raft to new locations. Seeds are buoyant, survive saltwater treatments and are impermeable to water suggesting they may be effective dispersers over long distances (Ishikawa et al., 1993; Yang et al., 2012). Seeds are wind, water or gravity dispersed (Ishikawa et al., 1993; Ohsako, 2010; Yang et al., 2012). Plants survive well after hurricanes, and appear to have spread into New York, USA, from New Jersey, USA, after Hurricane Sandy in 2012 (see Impacts section).

Accidental Introduction

Introductions to North America were accidental (associated with sand ballast dumps). In Oregon (Flora of North America Editorial Committee, 1993) and in northeastern USA, introduction is speculated to be associated with ship ballast, ships, ship wrecks or, less likely, packing materials (Small, 1954; Wootton, 2005; Wootton et al., 2007). C. kobomugi fragments could be carried in sand transported for construction, in sand-bagging or from cleaning up sand from dune blowouts. Transport of seeds or fragments could be possible where boats snag floating fragments or where people accidentally pick them up, for example at boat ramps.

Intentional Introduction

Most of the spread in northeastern USA, after its initial introduction in New Jersey (with the exception of plants found in 1941 in Virginia), was due to intentional planting for dune stabilization during the period from the 1960s to the 1980s (Small, 1954; Woodhouse, 1978; Shisler et al., 1987; Wootton et al., 2005; PCA Alien Plant Working Group, 2015).

Pathway Causes

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CauseNotesLong DistanceLocalReferences
DisturbanceDispersed to New York from New Jersey after Hurricane Sandy in 2012. Louise Wootton, Georgian Court Yes Yes Lamont and Young, 2014
Flooding and other natural disastersDispersed to New York from New Jersey after Hurricane Sandy in 2012. Louise Wootton, Georgian Court Yes Yes Lamont and Young, 2014
Habitat restoration and improvementWidely planted for dune erosion control in eastern USA between 1950s and 1980s. Possibly introduced Yes Yes Burkitt and Wootton, 2010; Wootton et al., 2005; Zhang et al., 2010

Pathway Vectors

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VectorNotesLong DistanceLocalReferences
Containers and packaging - woodProbably arrived to east and west coast of USA by sand ballast around the year 1900 Yes Consortium of Pacific Northwest Herbaria, 2015; Wootton et al., 2005
Ship ballast water and sedimentProbably arrived to east and west coast of USA by sand ballast around the year 1900 Yes Burkitt and Wootton, 2010; Consortium of Pacific Northwest Herbaria, 2015

Impact Summary

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CategoryImpact
Environment (generally) Positive and negative

Environmental Impact

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Impact on Habitats

Dune heights are probably lower where dunes are accreting in areas colonized with C. kobomugi (compared to areas with Ammophila breviligulata), potentially meaning the dunes are more prone to overwash during storms and accelerated landward migration (Shisler et al., 1987; Burkitt and Wootton, 2010). Dunes colonised by Carex kobomugi also appear to be more stable than those colonised by native species, making them less susceptible to blowouts (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2015).

C. kobomugi has impacted a number of protected natural areas and offshore islands in northeastern USA, including widespread sites in New Jersey (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014). Sites in New Jersey include: Gateway National Recreational Area (Burkitt and Wootton, 2010) which has over 60 acres affected by C. kobomugi (it is spreading rapidly into key piping plover breeding habitats); Monmouth Beach; and Sea Bright. Populations of C. kobomugi were extensive before Hurricane Sandy in 2012, but now only scatterd remnant populations remain, with more significant amounts at Seven Presidents County Park, Asbury Park (one population toward the north end of the township’s beaches), Sea Girt and Manasquan. Remnant populations are being manually removed using early detection and rapid response (EDRR) at Island Beach State Park where there was an extensive infestation with over 60 acres affected. Multiple populations were found in Barnegat Light Borough, Loveladies, Harvey Cedars Borough, North Beach, Surf City Borough, Beach Haven Borough and Holgate National Wildlife Refuge.

C. kobomugi was reported to be on Assateague Island National Seashore in Maryland, USA (PCA Alien Plant Working Group, 2015). It has also impacted Fisherman Island National Refuge in Virginia, USA (Boule, 1979).

Dr Louise Wootton (Georgian Court University, New Jersey, USA, personal communication, 2014) reports that C. kobomugi has been seen in New York, USA, at a few sites since Hurricane Sandy in 2012, including Statten Island at Crookes Point in Great Kills Park, Miller Field and Fort Wadsworth. It is also along many of the beaches in the Rockaways (Arverne Beach and others) and on Fire Island and more is suspected in areas outside the parks where populations are not being monitored. National Park Staff are regularly finding it; it seems plants in New Jersey blew off the north side of Sandy Hook and washed up all over the beaches in New York to the north and took root. Plants are known from Rhode Island at East Beach State Park and at Napatree Beach.

Impact on Biodiversity

C. kobomugi is believed to impact rare species, including piping plovers (Charadrius melodus), beach tiger beetles (Cicindela hirticollis) and seabeach amaranth (Amaranthus pumilus) through direct competition and/or reduction of habitat or food availability (Wootton et al., 2005). Reduction of habitat may be due to the fact that C. kobomugi appears to hyperstablize dunes, making them so stable that are not susceptible to blowouts. Blowouts are needed as habitat for these aforementioned high beach species (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2015).

American beachgrass (Ammophila breviligulata), seaside goldenrod (Solidago sempervirens), saltmeadow cordgrass (Spartina patens) and Artemisia species (belonging to the daisy family, Asteraceae) were all observed to have significantly lower (10-50 %) densities in invaded sites compared to uninvaded sites, and the more heavily disturbed sites had higher C. kobomugi densities (Burkitt and Wootton, 2010). The mechanism for the reduction is suggested to be competitive, via its dense mat formations, and possibly via allelopathy (Small, 1954; Burkitt and Wootton, 2010). However overall species richness was not significantly different between invaded and uninvaded sites. Hybridization has not been observed to occur.

Threatened Species

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Threatened SpeciesConservation StatusWhere ThreatenedMechanismReferencesNotes
Amaranthus pumilus (seabeach amaranth)NatureServe NatureServe; USA ESA listing as threatened species USA ESA listing as threatened species
Charadrius melodusNT (IUCN red list: Near threatened) NT (IUCN red list: Near threatened); National list(s) National list(s)
Cicindela hirticollis (hairy-necked tiger beetle)National list(s) National list(s)

Risk and Impact Factors

Top of page Invasiveness
  • Proved invasive outside its native range
  • Has a broad native range
  • Abundant in its native range
  • Pioneering in disturbed areas
  • Long lived
  • Has high reproductive potential
  • Has propagules that can remain viable for more than one year
  • Reproduces asexually
Impact outcomes
  • Damaged ecosystem services
  • Ecosystem change/ habitat alteration
  • Modification of successional patterns
  • Monoculture formation
  • Reduced native biodiversity
  • Soil accretion
  • Threat to/ loss of endangered species
  • Threat to/ loss of native species
Impact mechanisms
  • Competition - monopolizing resources
  • Competition - shading
  • Rapid growth
Likelihood of entry/control
  • Highly likely to be transported internationally deliberately
  • Difficult to identify/detect as a commodity contaminant
  • Difficult/costly to control

Uses

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There are possible benefits in using C. kobomugi for dune stabilization, but there are considerable doubts raised about its relative effectiveness compared to native species. Dune heights may be lower where it colonizes dunes which are just forming. If a dune was originally colonized and stabilized by Ammophila breviligulata then invasion by C. kobomugi results in a less substantial height difference (Woodhouse, 1978; Shisler et al., 1987; Burkitt and Wootton, 2010; Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2015). Carex kobomugi also appears to make dunes more stable than native species do, to the extent that they are hyperstablized (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2015).

Uses List

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Environmental

  • Land reclamation
  • Landscape improvement
  • Soil conservation

Diagnosis

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DNA-based identification using microsatellite loci is possible (King and Roalson, 2009a,b).

Detection and Inspection

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Useful identification keys are given in the Flora of North America and the Flora of China. Both are available online at www.efloras.org (Flora of North America Editorial Committee, 1993; Flora of China Editorial Committee, 2014).

Similarities to Other Species/Conditions

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The Flora of North America Editorial Committee (1993) has useful drawings of the both C. kobomugi and the closely related C. macrocephala. Carex kobomugi has higher shoot density and C. macrocephala has sturdier and more lush individual shoots, notably larger and darker coloured seed-heads, and perigynia with sharp distal beaks and proximate lacerate wings (Wootton, 2007).

Shared features for these two species of Carex are given by the Flora of North America Editorial Committee (1993). The key emphasizes “Perigynia with serrulate wing on margins; spikes usually 20+, sessile, pistillate or androgynous and similar in appearance, forming a dense, ovoid or oblong head, rarely with proximal spike separated”. 

Prevention and Control

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Prevention

C. kobomugi is banned from sale in Connecticut, USA.

Rapid response

The plant is subject to early detection and rapid response efforts in some northeastern USA states (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014; EDDMapS, 2015; PCA Alien Plant Working Group, 2015).

Public awareness

The plant is mentioned as a harmful invader or incipient invader in several descriptive articles and websites (Small, 1954; Enser, 2006; Lamont and Young, 2014; EDDMapS, 2015; PCA Alien Plant Working Group, 2015).

Control

Cultural control and sanitary measures

Picking of seed heads and fragments should reduce dispersal pressure.

Physical/mechanical control

Deep burial may be an effective means of control. Some of this occurred naturally after Hurricane Sandy and appears to have been effective (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014).  However, an experiment to assess this was recently carried out by Pedram Daneshgar, Ph.D. Monmouth University, Louise Wootton, Georgian Court, and their students (manuscript in prep).  They found that C. kobomugi was more successful than Ammophila breviligulata or Solidago semervirens in emerging from burial depths in excess of 18 inches.

Biological control

No natural enemies have been seen/documented in its introduced range; it appears to be relatively resistant to browsing by rabbits (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014).

Chemical control

Glyphosate is effective in reducing the extent of C. kobomugi, and with repeated treatments it may be effective in bringing it under control (Burkitt and Wootton, 2010). Sufficiently aggressive treatments are likely to result in some non-target plant damage especially to co-occurring native plants mentioned in the impacts section (Louise Wootton, Georgian Court University, New Jersey, USA, personal communication, 2014).

Gaps in Knowledge/Research Needs

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Little is known about natural enemies of C. kobomugi.

References

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Boule ME, 1979. The Vegetation of Fisherman Island, Virginia. Castanea, 44(2):98-108.

Burkitt J, Wootton L, 2010. Effects of disturbance and age of invasion on the impact of the invasive sand sedge, Carex kobomugi, on native dune plant populations in New Jersey's coastal dunes. Journal of Coastal Research, 27(1):182-193.

Carex Working Group, 2014. Identification Key to Sedges of the Pacific Northwest (and species list). USA: Oregon State University Press, 432 pp.

Consortium of Pacific Northwest Herbaria, 2015. Herbarium specimens from the Pacific Northwest. Seattle, Washington, USA: University of Washington Herbarium, Burke Museum of Natural History and Culture. http://www.pnwherbaria.org/

EDDMapS, 2015. Early detection and distribution mapping system. Tifton, Georgia, USA: The University of Georgia - Center for Invasive Species and Ecosystem Health. https://www.eddmaps.org/

Edelhauser B, 2011. The influence of nitrogen deposition on the competition between the native Ammophila breviligulata and the exotic, invasive Carex kobomugi. MS Thesis., USA: Georgian Court University. http://gcuonline.georgian.edu/wootton_l/edelhauser.htm

Enser, 2006. Is Carex kobomugi (Asiatic Sand Sedge) in Coastal Rhode Island a threat to the maritime/beach dune community? Rhode Island Naturalist newsletter, 13(1):4-7.

Flora of China Editorial Committee, 2014. Flora of China. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.efloras.org/flora_page.aspx?flora_id=2

Flora of North America Editorial Committee, 1993. Flora of North America: Volume 23. Magnoliophyta: Commelinidae (in Part). Cyperaceae. UK: Oxford University Press.

Govaerts R, Simpson DA, Goetghebeur P, Wilson K, Egorova T, Bruhl J, 2007. World Checklist of Cyperaceae. Surrey, UK: The Board of Trustees of the Royal Botanic Gardens, Kew.

Hayasaka D, Shimada N, Konno H, Sudayama H, Kawanishi M, Uchida T, Goka K, 2012. Floristic variation of beach vegetation caused by the 2011 Tohoku-oki tsunami in northern Tohoku, Japan. Ecological Engineering, 44:227-232. http://www.sciencedirect.com/science/article/pii/S0925857412001097

Hu Jun, Liu QiXin, Wu BaoCheng, Xiong YuNing, Dong ZhenGuo, Bian GuiLan, 2013. Species composition and community change of vegetation on coastal beaches of Haizhou Bay in Jiangsu Province. Journal of Plant Resources and Environment, 22(2):98-107.

Ishikawa SI, Furukawa A, Okuda T, Oikawa T, 1993. Germination requirements in Carex kobomugi (Sea Isle). Journal of Plant Research, 106(3):245-248.

Ishikawa SI, Kachi N, 1998. Shoot population dynamics of Carex kobomugi on a coastal sand dune in relation to its zonal distribution. Australian Journal of Botany, 46(1):111-121.

Khan SA, Hamayun M, Kim HoYoun, Yoon HyeokJun, Seo JongCheol, Choo YeonSik, Lee InJung, Kim SangDal, Rhee InKoo, Kim JongGuk, 2009. A new strain of Arthrinium phaeospermum isolated from Carex kobomugi Ohwi is capable of gibberellin production. Biotechnology Letters, 31(2):283-287. http://springerlink.metapress.com/content/3487m30057060160/?p=186039df97aa48fcb056e02a9eb812f0&pi=16

Kim KD, 2005. Invasive plants on disturbed Korean sand dunes. Estuarine, Coastal & Shelf Science, 62(1/2):353-364. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WDV-4DSW9XS-1&_user=3891418&_handle=V-WA-A-W-BA-MsSAYWA-UUW-U-AABBEBDVBV-AABACAYWBV-VCZZVDCCW-BA-U&_fmt=full&_coverDate=01%2F01%2F2005&_rdoc=28&_orig=browse&_srch=%23toc%236776%232005%23999379998%23535048!&_cdi=6776&view=c&_acct=C000028398&_version=1&_urlVersion=0&_userid=3891418&md5=675e53cfb2dcabd57f017ce8f3e95677

King MG, Horning ME, Roalson EH, 2009. Range persistence during the last glacial maximum: Carex macrocephala was not restricted to glacial refugia. Molecular Ecology, 18(20):4256-4269. http://www.blackwell-synergy.com/loi/mec

King MG, Roalson EH, 2009. Discordance between phylogenetics and coalescent-based divergence modelling: exploring phylogeographic patterns of speciation in the Carex macrocephala species complex. Molecular Ecology, 18(3):468-482. http://www.blackwell-synergy.com/loi/mec

King MG, Roalson EH, 2009. Isolation and characterization of 11 microsatellite loci from Carex macrocephala (Cyperaceae). Conservation Genetics, 10(3):531-533. http://springerlink.metapress.com/link.asp?id=105709

Lamont E, Young S, 2014. Noteworthy plants recently reported from Long Island, New York. Long Island Botanical Society Newsletter, 24(3):21-28.

Matsuoka H, Akiyama M, Kobayashi K, Yamaji K, 2013. Fe and P solubilization under limiting conditions by bacteria isolated from Carex kobomugi roots at the Hasaki coast. Current Microbiology, 66(3):314-321. http://rd.springer.com/article/10.1007/s00284-012-0276-3

Ohsako T, 2010. Clonal and spatial genetic structure within populations of a coastal plant, Carex kobomugi (Cyperaceae). American Journal of Botany, 97(3):458-470. http://www.amjbot.org/

PCA Alien Plant Working Group, 2015. Asiatic sand sedge (Carex kobomugi). Plant Conservation Alliance, Alien Plant Working Group. http://www.nps.gov/plants/alien/fact/cako1.htm

Roalson EH, 2008. A synopsis of chromosome number variation in the Cyperaceae. Botanical Review, 74(2):209-393. http://www.springer.com/life+sci/plant+sciences/journal/12229

Shisler J, Wargo R, Jordan R, 1987. Evaluation of Japanese sedge, Carex kobomugi, for use in coastal dune planting and stabilization. New Brunswick, New Jersey, USA: New Jersey Agriculture Experiment Station Publication, P-40502-03-87.

Small JA, 1954. Carex kobomugi at Island Beach, New Jersey. Ecology, 35(2):289-91.

Standley LA, 1983. Carex kobomugi Owhi, an adventive sedge new to New England. Rhodora, 85(842):265-267.

Weakley AS, 2012. Flora of the southern and mid-Atlantic states. USA: University of North Carolina Herbarium, North Carolina Botanical Garden.

Woodhouse WW Jr, 1978. Dune building and stabilization with vegetation. Fort Belvoir, Virginia, USA: US Army, Corps of engineers, 112.

Wootton L, 2007. First report of Carex macrocephala in eastern North America with notes on its co-occurrence with Carex kobomugi in New Jersey. Journal of the Torrey Botanical Society, 134(1):126-134. http://www.torreybotanical.org/journal.html

Wootton LS, Halsey SD, Bevaart K, McGough A, Ondreicka J, Patel P, 2005. When invasive species have benefits as well as costs: managing Carex kobomugi (Asiatic sand sedge) in New Jersey's coastal dunes. Biological Invasions, 7(6):1017-1027. http://www.springerlink.com/content/l7423g8782656263/fulltext.pdf

Yang H, Lu Q, Wu B, Zhang J, 2012. Seed dispersal of east Asian coastal dune plants via seawater - short and long distance dispersal. Flora-Morphology, Distribution, Functional Ecology of Plants, 207(10):701-706.

Yura H, Ogura A, 2006. Sandblasting as a possible factor controlling the distribution of plants on a coastal dune system. Plant Ecology, 185(2):199-208. http://springerlink.metapress.com/link.asp?id=100328

Zhang FP, Li CF, Tong LG, Yue LX, Li P, Ciren YJ, Cao CG, 2010. Response of microbial characteristics to heavy metal pollution of mining soils in central Tibet, China. Applied soil ecology, 45(3):144-151.

Links to Websites

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WebsiteURLComment
Consortium of Pacific Northwest Herbariahttp://pnwherbaria.org
EDDMapS, 2015http://www.eddmaps.org/ipane/ipanespecies/herbs/carex_kobomugi.htm
PCA Alien Plant Working Group - Asiatic Sand Sedge (Carex kobomugi) 2015http://www.nps.gov/plants/alien/fact/cako1.htm

Contributors

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31/07/2015 Original text by:

Christopher Buddenhagen, Florida State University, USA

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