Biologist Joe Patt (The Nature Conservancy, Delaware Bayshores Office) is conducting studies of population dynamics, pollination and herbivory on the Maurice River watershed population of A. virginica. He notes high variability in population numbers from year to year (fluctuating from thousands to tens of thousands of plants), and is devising a consistent transect method for censusing plants.

Jerry M. Baskin (University of Kentucky) received funding from the U. S. Fish and Wildlife Service to study seed germination in A. virginica. The species germinates without dormancy following scarification and treatment with 30 oC/15 oC temperatures in the laboratory (Baskin and Baskin 1998: 494).

Graduate student, Alan Griffith (University of Maryland) is completing his doctoral dissertation on metapopulation dynamics of Aeschynomene virginica. He has transplanted seedlings of the plant to research plots and notes that survivorship and seed production of A. virginica are significantly higher in areas where other vegetation has been cleared. Survivorship of seedlings is still below 20%, however.

24 populations of Aeschynomene virginica are documented in the original recovery plan, but one historic population in Virginia was rediscovered in 2001. New Jersey supports several thousand plants in 2 populations: one in the Maurice River watershed and one near the Hudson (American Museum of Natural History 2001, Joseph Patt [The Nature Conservancy] unpublished data). Maryland has one population of several hundred plants. North Carolina's ditch populations are very small and variable from year to year. Virginia reports approximately 5,000 plants altogether. Therefore, the global population is on the order of 10,000 plants (USFWS 1992). Population numbers fluctuate widely among years, making global population estimates problematic. Student Elizabeth Mountz presented an abstract discussing the identification of essential habitat for A. virginica at the 2000 Student Research Conference for the Virginia Space Grant Consortium, Old Dominion University, Norfolk, Virginia (contact conference organizer, Heidi B. Davis [hbdavis@odu.edu] for information on obtaining conference proceedings).

Allozyme variation distinguishing Aeschynomene virginica from congeners has been documented (Carulli and Fairbrothers 1988). The Chloroplast DNA (cDNA) sequence has been published for the taxon (GenBank release 123.0, April 2001).

The New England Wild Flower Society and partners in mid-Atlantic states have collected seeds from several populations. Accessions are also held by the National Seed Storage Laboratory in Fort Collins, Colorado.

The New England Wild Flower Society and partners in mid-Atlantic states have collected seeds from several populations. Accessions are also held by the National Seed Storage Laboratory in Fort Collins, Colorado.

There are about 20 remaining occurrences, including a couple of unstable ditch populations. The plants are restricted to the relatively limited zone of fresh water habitat that is tidally influenced. Habitat alteration has been, and continues to be, a severe threat to this species' continued existence. Many sites where it occurred historically have been dredged, filled, or bulkheaded. Surviving occurrences are potentially threatened by many factors related to increased population growth, including road construction, residential and commercial development, water pollution, water withdrawal projects, and bank erosion from motorboat traffic. Insect predation on seed pods and displacement by aggressive, non-native plant species are also threats.

As identified by the U. S. Fish and Wildlife Service (1992): Habitat destruction due to shoreline stabilization, rip-rapping, channelization, and dredging to support residential, commercial, and industrial development Shoreline erosion due to boat

24 populations of Aeschynomene virginica are documented in the original recovery plan, but one historic population in Virginia was rediscovered in 2001. New Jersey supports several thousand plants in 2 populations: one in the Maurice River watershed and one near the Hudson (American Museum of Natural History 2001, Joseph Patt [The Nature Conservancy] unpublished data). Maryland has one population of several hundred plants. North Carolina's ditch populations are very small and variable from year to year. Virginia reports approximately 5,000 plants altogether. Therefore, the global population is on the order of 10,000 plants (USFWS 1992). Population numbers fluctuate widely among years, making global population estimates problematic.

Allozyme variation distinguishing Aeschynomene virginica from congeners has been documented (Carulli and Fairbrothers 1988). The Chloroplast DNA (cDNA) sequence has been published for the taxon (GenBank release 123.0, April 2001) Botanist Gerry Moore (Brooklyn Botanical Garden) has surveyed extensive areas of the Maurice River watershed in New Jersey for additional populations of Aeschynomene virginica. Graduate student, Alan Griffith (University of Maryland) is completing his doctoral dissertation on metapopulation dynamics of Aeschynomene virginica. He has transplanted seedlings of the plant to research plots and notes that survivorship and seed production of A. virginica are significantly higher in areas where other vegetation has been cleared. Survivorship of seedlings is still below 20%, however. Jerry M. Baskin (University of Kentucky) received funding from the U. S. Fish and Wildlife Service to study seed germination in A. virginica. The species germinates without dormancy following scarification and treatment with 30 oC/15 oC temperatures in the laboratory (Baskin and Baskin 1998: 494). Student Elizabeth Mountz presented an abstract discussing the identification of essential habitat for A. virginica at the 2000 Student Research Conference for the Virginia Space Grant Consortium, Old Dominion University, Norfolk, Virginia (contact conference organizer, Heidi B. Davis [hbdavis@odu.edu] for information on obtaining conference proceedings). Biologist Joe Patt (The Nature Conservancy, Delaware Bayshores Office) is conducting studies of population dynamics, pollination and herbivory on the Maurice River watershed population of A. virginica. He notes high variability in population numbers from year to year (fluctuating from thousands to tens of thousands of plants), and is devising a consistent transect method for censusing plants. Professor Peter F. Straub of Richard Stockton College of New Jersey is measuring homozygosity levels in populations of A. virginica. The New England Wild Flower Society and partners in mid-Atlantic states have collected seeds from several populations. Accessions are also held by the National Seed Storage Laboratory in Fort Collins, Colorado.

Currently, sites in Virginia and New Jersey are protected by The Nature Conservancy The Nature Conservancy in New Jersey is removing invasive Phragmites australis near one population along the Manumuskin River (contact Joe Patt, TNC, jpatt@tnc.org for more information)

What is needed: A survey of the prevalence and impacts of invasive species on existing populations is needed, and the effect of invasive species removal on this species needs to be monitored Studies of the impacts of nutrient loading on ecophysiology, symbiotic nodulation, and fitness of A. virginica. Studies to inform the creation of habitat or optimal conditions for establishment of A. virginica Study of the impacts of rising sea level (increased salinity) on A. virginica and other freshwater wetland plant species Basic information on pollinator identity, herbivores, nodulation symbionts, and other factors influencing establishment and fitness

Systematic seed germination trials should be initiated Propagation of A. virginica for wetland restoration and possible mitigation would also be beneficial