Description
Synonomy- 'Aneilema keisack' (Sipple and Wheeler 1974) is a misspelling. Aneilema nudiflora (=Murdannia nudiflora) is a misidentification (Hotchkiss 1940).
Potentially Misidentified Species- Murdannia nudiflora (Nakedstem Dewflower) is introduced to FL and Gulf states to TX (Gleason and Cronquist 1991).
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Plantae | Magnoliophyta | Liliopsida | Commelinales | Commelinaceae | Murdannia |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1939 | Established | Expanding | Introduced | Regular Resident | North America | East Asia | Natural Dispersal(Natural Dispersal) |
History of Spread
Murdannia keisak (Asian Dewflower) is native to east Asia, including Japan, China, and Taiwan. Dunn and Sharitz (1990) suggest that M. keisak was introduced to North America during the period of extensive rice cultivation in the Southeast United States, before 1860, perhaps as early as the 1600's, but was suppressed by intensive hand picking of weeds, until rice cultivation was reduced or abandoned by the 1920's. Its first North American record is an herbarium specimen collected in 1927 in LA (Dunn and Sharitz 1990). In 1935, its seeds were identified (as Aneilema nudiflorum) in the stomach of ducks from the Santee River Delta SC (Hotchkiss 1940). First records in other southeastern states were: NC - 1948, Smith Creek, Wilmington NC (Hotchkiss 1951); GA - 1948, Altamaha River, GA (Hotchkiss 1951); AR- 1960s (Dunn and Sharitz 1990; FL- 1960s (Dunn and Sharitz 1990). Murdannia keisak is now widespread in the southeastern US, from FL-LA north to AR, KY, and MD (Natural Resources Conservation Service). Murdannia keisak has also been found in fresh tidal marshes of the Columbia River WA-OR (Dunn and Sharitz 1990; Natural Resources Conservation Service 2001).
In 1939, Murdannia keisak was found to be abundantly growing along the tidal fresh James River VA, at Harrison Point (Fernald 1940). This species appears to have increased greatly in abundance throughout tidal-fresh oligohaline regions around central and southern Chesapeake Bay, as well as in nontidal interior wetlands. It was considered infrequent or rare in MD by Riefner and Hill (1983), but is now an important biomass component in many tidal wetlands (Fowler and Kershner 1989; Sipple 1995; Silberhorne 1995).
Chesapeake Bay Records are summarized below:
James, Chickahominy, Pamunkey (York) Rivers - In 1939 M. keisak was collected in the James; Chickahominy; Pamunkey Rivers where it was common to abundant in tidal fresh marshes (Fernald 1940; Hotchkiss 1951). In 1984-85, it was reported as the second-ranking species in biomass in the understory of tidal Cohoke Swamp, Pamunkey River (Fowler and Hershner 1989).
Rappahannock, Potomac Rivers 1947-1949. (Hotchkiss 1951). Dense thickets of M. keisak were seen in Potomac tidal fresh marshes at Theodore Roosevelt Island DC, Dyke Marsh, Alexandria VA and Mason Neck State Park VA, in 1995-2000 (Fofonoff 1995 personal observation). This plant was occasional in fresh-oligohaline Brent Marsh, Stafford County VA (1987-94) (Strong and Kelloff 1994).
Patuxent River - At the Patuxent Wildlife Research Center in Bowie MD, Sipple and Wheeler 1974). Murdannia keisak was transplanted from King George County VA as a wildlife food in 1950 (Riefner and Hill 1990). However, it was not found in a later survey of Patuxent tidal marshes (Anderson et al. 1968) or at Jug Bay by Khan (personal communication 1995). It is now abundant in marshes hear the head of tide of the Patuxent (Fofonoff, personal observation, 2003).
Eastern Shore Tributaries - Murdannia keisak was collected at the Wicomico River, Wicomico County MD 1971 (Sipple and Wheeler 1974), and later became more widespread in tidal fresh Eastern Shore tributaries (Sipple 1978; Sipple 1995).
History References - Dunn and Sharitz 1990; Fernald 1940; Fowler and Hershner 1989; Harville et al. 1986; Hotchkiss 1940; Hotchkiss 1951; Natural Resources Conservation Service 2001; Riefner and Hill 1983; Sipple and Wheeler 1974; Strong and Kelloff 1994; Thomas 1980
Invasion Comments
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | 35.0 | 35.0 | ||
| Salinity (‰) | 0.0 | 0.0 | ||
| Oxygen | ||||
| pH | ||||
| Salinity Range | fresh-oligo |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | 300.0 | 300.0 |
| Typical Adult Size (mm) | 650.0 | 650.0 |
| Maximum Adult Size (mm) | 1000.0 | 1000.0 |
| Maximum Longevity (yrs) | 0.5 | 0.5 |
| Typical Longevity (yrs | 0.5 | 0.5 |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
|||
| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
|||
| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
|||
| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Murdannia keisak (Asian Dewflower) is not considered a problem in MD or VA at this time (Sipple 1995; Silberhorne 1996), but is viewed with some concern because of rapid spread. This plant is on a list of invasive plants for VA (Virginia Department of Conservation and Recreation 1999).
Aesthetic - Large sprawling thickets in shallow water, mudflats, and marshes, could be regarded as unattractive at high densities.
Fisheries (=Wildlife) - Seeds are eaten by ducks (Hotchkiss 1940), and have been sometimes deliberately planted as a wildlife food (Riefner and Hill 1983).
References - Hotchkiss 1940; Riefner and Hill 1983; Sipple 1995; Silberhorne 1996; Virginia Department of Conservation and Recreation 1996.
Economic Impacts Outside of Chesapeake Bay
Murdannia keisak is becoming widespread across the southeast United States and has spread to new areas such as the Columbia River Valley (Dunn and Sharitz 1990). It is regarded as a threat to biodiversity of wetland flora (Virginia Department of Conservation and Recreation 1999). However, negative economic impacts of its invasion are not clear at this time. It does seem to be a good source of food for waterfowl (Hotchkiss 1940), but negative effects, including competition with other food species, or habitat modification, owing to its peculiar growth mode, are possible, but not documented. M. keisak is a major weed of rice in Asia (Dunn and Sharitz 1990).
References - Dunn and Sharitz 1990; Hotchkiss 1940; irginia Department of Conservation and Recreation 1999
Ecological Impacts on Chesapeake Native Species
Murdannia keisak (Asian Dewflower) has apparently greatly increased its abundance in fresh tidal tributaries of lower Chesapeake Bay in the last two decades (Sipple 1995; Silberhorne 1996).
Competition - Murdannia keisak has growth and demographic properties that are typical of invasive wetland plants, and contribute to its dominance in disturbed wetland areas (Dunn and Sharitz 1991). Murdannia keisak was not considered a problem in MD or VA at this time by two local botanists (Sipple 1995; Silberhorne 1996), but it is on a list of invasive plants of VA (Virginia Department of Conservation and Recreation 1999). However, both Sipple and Silberhorne considered the spread of M. keisak and its increase in biomass as one of the major changes in Chesapeake flora over the last 30 years. Murdannia keisak is reported to crowd out native vegetation in wetlands through rapid vegetative reproduction and intense seed production (Virginia Department of Conservation and Recreation 1999). In experiments with an endangered inland wetland plant, in NC spring seeps, Sagittaria fasciculata (Bunched Arrowhead), weeding of seedlings of M. keisak increased survival of S. fasciculata (Newberry 1991).
Food/Prey- Murdannia keisak seeds were found in duck stomachs in SC (Hotchkiss 1940) and appear to be an important waterfowl food (Dunn and Sharitz 1990). M. keisak was transplanted from King George County VA; to the Patuxent Wildlife Research Center as a wildlife food in 1950 (Riefner and Hill 1990).
References - Dunn and Sharitz 1990; Dunn and Sharitz 1991; Hotchkiss 1940; Newberry 1991; Riefner and Hill 1990; Sipple 1995; Silberhorne 1996; Virginia Department of Conservation and Recreation 1999.
Ecological Impacts on Other Chesapeake Non-Native Species
Murdannia keisak (Asian Dewflower) appears to be spreading rapidly in fresh tidal wetlands of the Chesapeake (Silberhorne 1996; Sipple 1995). It appears to be highly competitive; but specific impacts on introduced species have not been noted.
References- Silberhorne 1996; Sipple 1995
References
Brown, Melvin L.; Brown, Russell G. (1984) Herbaceous Plants of Maryland, , College Park. Pp.Dunn, Christopher P.; Sharitz, Rebecca (1990) The history of Murdannia keisak (Commelinaceae) in the southeastern United States, Castanea 55: 122-129
Dunn, Christopher P.; Sharitz, Rebecca R. (1991) Population structure, biomass allocation, and phenotypic plasticity in Murdannia keisak (Commelinaceae), American Journal of Botany 78: 1712-1723
Fernald, Merritt L. (1940) A century of additions to the Virginia flora, Rhodora 42: 390-498, -503-521
Fernald, Merritt L. (1950) Gray's Manual of Botany, In: (Eds.) . , New York. Pp.
Fowler, B. Keith; Hershner, Carl (1989) Primary production in Cohoke Swamp, a tidal freshwater wetland in Virginia, In: Sharitz, R. R., and Gibbons, J. W.(Eds.) Freshwater Wetlands and Wildlife. , Oak Ridge, TN. Pp. 365-374
Gleason, Henry A.; Cronquist, Arthur (1991) Manual of vascular plants of northeastern United States and adjacent Canada, In: (Eds.) . , Bronx, New York. Pp.
Godfrey, R. K.; Wooten, Jean W. (1979) Aquatic and Wetland Plants of the Southeastern United States: Monocotyledones., In: (Eds.) . , Athens. Pp.
Harvill, A. M., Jr.; Bradley, T. R.; Stevens, C. E.; Weiboldt, T.F.; Ware, D.E.; Ogle, D. W. (1986) Atlas of the Virginia Flora, , Farmville, VA. Pp.
Harvill, A. M.; Bradley, Ted R.; Stevens, Charles E.; Wieboldt, Thomas F.; Ware, Donna M. E.; Ogle, Douglas W.; Ramsey, Gwynn W.; Fleming, Gary P. (1992) Atlas of the Virginia Flora, , Burkeville, VA. Pp.
Hotchkiss, Neil (1940) Range extensions of marsh and aquatic plants, Rhodora 40: 20-22.
Hotchkiss, Neil (1951) Range extensions of marsh and aquatic plants. 2., Rhodora 53: 91-93
Hotchkiss, Neil (1972) Common Marsh, Underwater, and Floating-Leaved Plants of the United States and Canada, , New York. Pp.
Kartesz, John T. (1994) A synonymized checklist of the vascular flora of the United States, Canada, and Greenland., In: (Eds.) . , Portland OR. Pp.
1997-2024 USDA PLANTS Database.. Onine databse
Newberry, Gillian (1991) Factors affecting the survival of the rare plant, Sagittaria fasciculata., Castanea 56: 59-64
Resource Management Inc. (1993) National list of plant species that occur in wetlands., , Minneapolis.. Pp.
Riefner, Richard E.; Hill, Steven R. (1983) Notes on infrequent and threatened plants of Maryland including new state records, Castanea 48: 117-137
Shinners, Lloyd H. (1962) Aneilema (Commelinaceae) in the United States, Sida 1: 100-101
Silberhorne, Eugene (December 1995) Introduced plants in the Chesapeake Bay region, telephone conversation;, , Gloucester Point VA. Pp.
Simmons, Mark P.; Ware, Donna M.; Hayden, W. John (1995) The vascular flora of the Potomac River watershed of King George County, Virginia, Castanea 60: 179-209
1995 Introduced plants in Chesapeake Bay, letters and telephone conversations.
Sipple, William S.; Wheeler, Richard H. (1974) On the presence of three vascular plants, Melothria pendula, Carex extensa, and Aneilema keisack in Maryland, Chesapeake Science 25: 173-174
Strong, Mark T.; Kelloff, Carol L. (1994) Intertidal vascular plants of Brent Marsh, Potomac River, Stafford County, Virginia, Castanea 59: 354-366
1999 Invasive Alien Plant Species of Virginia. http://www.state.va.us/~dcr/dnh/invlist.htm
Wass, Melvin L. (1972) A checklist of the biota of lower Chesapeake Bay, Special Scientific Report, Virginia Institute of Marine Science 65: 1-290