Murdannia keisak - (Hassk.) Hand.-Maz.
Marsh Dewflower
Other English Common Names: Aneilema
Other Common Names: wartremoving herb
Synonym(s): Aneilema keisak Hassk.
Taxonomic Status: Accepted
Related ITIS Name(s): Murdannia keisak (Hassk.) Hand.-Maz. (TSN 39145)
Unique Identifier: ELEMENT_GLOBAL.2.133770
Element Code: PMCOM07010
Informal Taxonomy: Plants, Vascular - Flowering Plants - Spiderwort Family
 
Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Monocotyledoneae Commelinales Commelinaceae Murdannia
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Concept Reference
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Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Murdannia keisak
Taxonomic Comments: Native to Asia, introduced into North America in the 20th century and still expanding its range (R. Faden, FNA review draft, 5/98). Sometimes treated as Aneilema keisak.
Conservation Status
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NatureServe Status

Global Status: GNR
Global Status Last Changed: 07Aug2001
Rounded Global Status: GNR - Not Yet Ranked
Nation: United States
National Status: NNA

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (SNA), Arkansas (SNA), Delaware (SNA), Florida (SNA), Georgia (SNR), Kentucky (SNA), Louisiana (SNA), Maryland (SNA), North Carolina (SNA), Oregon (SNA), South Carolina (SNA), Tennessee (SNA), Virginia (SNA), Washington (SNA)

Other Statuses

NatureServe Global Conservation Status Factors

Other NatureServe Conservation Status Information

Distribution
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U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
NOTE: The distribution shown may be incomplete, particularly for some rapidly spreading exotic species.

U.S. & Canada State/Province Distribution
United States ALexotic, ARexotic, DEexotic, FLexotic, GA, KYexotic, LAexotic, MDexotic, NCexotic, ORexotic, SCexotic, TNexotic, VAexotic, WAexotic

Range Map
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Ecology & Life History Not yet assessed
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Economic Attributes Not yet assessed
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Management Summary Not yet assessed
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Population/Occurrence Delineation Not yet assessed
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Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank)
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Disclaimer: While I-Rank information is available over NatureServe Explorer, NatureServe is not actively developing or maintaining these data. Species with I-RANKs do not represent a random sample of species exotic in the United States; available assessments may be biased toward those species with higher-than-average impact.

I-Rank: Medium/Low
Rounded I-Rank: Medium
I-Rank Reasons Summary: Murdannia keisak is an invasive wetland plant that occurs from Virginia south to Florida and west to Arkansas and Louisiana. It has also been reported from the Columbia River estuary in Washington and Oregon. This species is known to alter the ecosystems in which it occurs, namely it stabilizes the soil in wetland areas where there is normally running water. It accomplishes this successional change by reducing water flow rates in seeps and aids in stabilizing the muck surface. Stabilization leads to encroachment of other species with vegetation, eventually filling up the seep. This invasive species threatens the federally listed Sagittaria fasciculata which requires running water. M. keisak is known to invade pond and stream edges, freshwater marshes and freshwater tidal marshes. This species is spreading in Virginia, Tennessee, Alabama, and Mississippi. This species produces thousands of tiny seeds, reproduces vegetatively and is known to form dense mats, and is commonly dispersed by waterfowl that prefer the seeds. Overall, this species is ranked 'medium/low', however, it is probably closer to a medium since it does appear to be a somewhat aggressive invader. What lowers its rank is the fact that it is currently known from mostly the Atlantic coastal states and two states in the west.
Subrank I - Ecological Impact: Medium
Subrank II - Current Distribution/Abundance: Low/Insignificant
Subrank III - Trend in Distribution/Abundance: Medium
Subrank IV - Management Difficulty: Unknown
I-Rank Review Date: 30Apr2004
Evaluator: Oliver, L.
Native anywhere in the U.S?
Native Range: This species is native to Asia (GRIN, DCR and VNPS 1999). Specifically, this species is native to China, Japan, Korea and Tibet (DCR and VNPS 1999).

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Screening Questions

S-1. Established outside cultivation as a non-native? YES
Comments: This species is established as a non-native species in the United States in much of the southeast. It is reported from Virginia south to Florida and west to Louisiana and Arkansas. It has also been reported in Washington and Oregon (Kartesz 1999).

S-2. Present in conservation areas or other native species habitat? Yes
Comments: This species is documented in native species habitat, specifically freshwater marshes, pond and stream edges and freshwater tidal marshes (DCR and VNPS 1999).

Subrank I - Ecological Impact: Medium

1. Impact on Ecosystem Processes and System-wide Parameters:Moderate significance
Comments: This wetland, exotic species alters sedimentation rate in the wetland areas it occurs in by stabilizing soil. It accomplishes this successional change by reducing water flow rates in seeps and aids in stabilizing the muck surface. Stabilization leads to encroachment of other species with vegetation, eventually filling up the seep. It also shades out native species and competes with them for nutrients and space (Newberry 1991).

2. Impact on Ecological Community Structure:Moderate significance
Comments: This species is an herbaceous plant (DCR and VNPS 1999), so it can only affect one vegetative layer. It has been reported to shade out native species (Newberry 1991), so species (animal or plant) that live in the water below it may be negatively affected by Murdannia keisak.

3. Impact on Ecological Community Composition:Moderate significance
Comments: Murdannia keisak is an introduced, invasive species that is known to form dense mats (DCR and VNPS 1999).

4. Impact on Individual Native Plant or Animal Species:Moderate significance
Comments: Murdannia keisak has been reported as a problematic species where the native, rare, and federally listed Sagittaria fasciculata occurs. S. fasciculata occurs in two counties in the Carolinas and M. keisak is known to stabilize the soil where this species grows. S. fasciculata requires shaded constantly flowing seeps over a substrate of hydrated muck-sand suspension and M. keisak impedes waterflow needed by this rare species (Newberry 1991).

5. Conservation Significance of the Communities and Native Species Threatened:High/Moderate significance
Comments: Murdannia keisak threatens the federally listed Saigttaria fasiculata which is known from only two counties in the Carolinas (Newberry 1991). It also occurs in other native species habitats including pond and stream edges, and tidal freshwater marshes (DCR and VNPS 1999).

Subrank II. Current Distribution and Abundance: Low/Insignificant

6. Current Range Size in Nation:Low significance
Comments: This species occurs from Virginia south to Florida, and west to Arkansas and Louisana. It is also reported in Oregon and Washington (Kartesz 1999). In the west, however, it is only known from one freshwater tidal marsh in the Columbia River estuary located between Oregon and Washington (DCR and VNPS 1999).

7. Proportion of Current Range Where the Species is Negatively Impacting Biodiversity:Medium significance/Insignificant
Comments: This species is reported as a threat to biodiversity in at least Virginia (DCR and VNPS 1999) and the Carolinas (Newberry 1991), however, it is not clear in the other states where it occurs how much a problem this species possess.

8. Proportion of Nation's Biogeographic Units Invaded:Low significance
Comments: Murdannia keisak occurs in more than 3 but less than 13 ecoregions (TNC 2001), as it occurs in much of the southeast and two states in the west.

9. Diversity of Habitats or Ecological Systems Invaded in Nation:Moderate significance
Comments: Murdannia keisak invades freshwater marshes, the edges of streams and ponds and freshwater tidal marshes (DCR and VNPS 1999). It is also known to invade ravine floodplains in Virginia (McDonald 2000).

Subrank III. Trend in Distribution and Abundance: Medium

10. Current Trend in Total Range within Nation:Moderate significance
Comments: This wetland, invasive plant is spreading in several of the states where it is reported from. The Virginia Department of Conservation and Recreation and the Virignia Native Plant Society (1999) indicate that this species is spreading in Virginia (in the Piedmont and Ridge and Valley), in Tennessee, northern Alabama, and northern Mississippi (DCR and VNPS 1999).

11. Proportion of Potential Range Currently Occupied:Medium/Low significance
Comments: Murdannia keisak was believed to only occurs in the eastern coastal states from Delaware to Louisiana, and Kentucky and Tennessee. It has also been discovered in the west in Oregon and Washington, in the Columbia River estuary (DCR and VNPS 1999). This species is spreading in Piedmont, Ridge and Valley in Virginia, Tennessee, northern Alabama, and northern Mississippi (DCRand VNPS 1999).

12. Long-distance Dispersal Potential within Nation:High/Moderate significance
Comments: The seeds of Murdannia keisak are eaten, and even preferred, by waterfowl (DCR and VNPS 1999). These waterfowl certainly carry and deposit the seeds long distances.

13. Local Range Expansion or Change in Abundance:Moderate significance
Comments: This species is spreading locally in Virginia (in the Ridge and Valley and in the Piedmont). It is also spreading in Tennessee, northern Alabama, and northern Mississippi (DCR and VNPS 1999).

14. Inherent Ability to Invade Conservation Areas and Other Native Species Habitats:Medium/Low significance
Comments: This species has invaded stream and pond edges, and freshwater wetlands (DCR and VNPS 1999). These habitats do experience natural disturbance.

15. Similar Habitats Invaded Elsewhere:Unknown

16. Reproductive Characteristics:Moderate significance
Comments: Murdannia keisak produces thousands of very small seeds and also reproduces vegetatively (DCR and VNPS 1999).

Subrank IV. General Management Difficulty: Unknown

17. General Management Difficulty:High/Low significance
Comments: This species is managed for in at least the state of Virginia. Manual removal of this species is not recommended since stem fragments are capable of sprouting. Biodegradable heribicide is suggested (DCR and VNPS 1999).

18. Minimum Time Commitment:Unknown

19. Impacts of Management on Native Species:Unknown

20. Accessibility of Invaded Areas:Unknown
Authors/Contributors
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Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

References
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  • Department of Conservation and Recreation and the Virginia Native Plant Society. 1999. Invasive Alien Plant Species in Viriginia. Aneilema (Murdannia keisak (Hasskarl) Hand. - Mazz). Online at: http://www.dcr.state.va.us/dnh/fsmuke.pdf. Accessed on April 30, 2004.

  • Kartesz, J. T. 1991. Synonym names from 1991 checklist, as extracted by Larry Morse, TNC, June 1991.

  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.

  • McDonald. L.E. 2000. Plant species of the Virginia Coastal Plain flora that are disjunct from the mountains. their distribution, abundance and substrate selectivity. Unpublished Masters Thesis. College of William and Mary in Viriginia, Williamsburg, VA.

  • Newberry, G. 1991. Factors affecting the survival of the rare plant Sagittaria fasciculata E. O. Beal Alismataceae. Castanea 56(1): 59-64.

  • The Nature Conservancy. 2001. Map: TNC Ecoregions of the United States. Modification of Bailey Ecoregions. Online . Accessed May 2003.

  • USDA, ARS, National Genetic Resources Program. 2001. Germplasm Resources Information Network - (GRIN). [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland.URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?6438. (Accessed 2004)

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