Status of the federally listed Aeschynomene virginica (L.) BSP. on the James River in Virginia-A new population of Aeschynomene virginica (L.) BSP.

VIRGINIA-A new population of Aeschynomene virginica (L.) BSP. (sensitive joint-vetch), a member of the Fabaceae, was located on the James River in 1998. Five plants were found on 2 September within a 2.0 by 4.0 m area at the edge of a channel that drains an extensive freshwater tidal marsh at the north end of Turkey Island. Five additional plants were located on 14 October within a 2.0 by 2.5 m area 1.1 km to the north along Turkey Island Creek in a similar habitat. The new stations represent the furthest known upstream locations for the species on the James River.

Both marshes where the new A. virginica stations occur are dominated by Zizania aquatica L. A diverse assemblage of associated plants includes Polygonum punctatum ElL, Bidens laevis (L.) BSP., Amaranthus cannabinus (L.) Sauer, Pontederia cordata L., Peltandra virginica (L.) Schott, Sagittaria latifolia Willd., Impatiens capensis Meerb., Kosteletzkya virginica (L.) K. Presl ex Gray, Asclepias incarnata L., Echinochloa walteri (Pursh) Heller, Leersia oryzoides (L.) Sw., Cinna arundinacea L., Boehmeria cylindrica (L.) Sw., Chamaecrista fasciculata (Michx.) Greene var. macrosperma (Fern.) C.F. Reed, Strophostyles umbellata (Muhl. ex Willd.) Britt. var. paludigena Fern., and Rhynchospora macrostachya Torr. ex Gray var. colpophila Fern. & Gale.

Aeschynomene virginica is a robust annual of fresh to oligohaline tidal marshes. It is extant in New Jersey, Maryland, Virginia, and North Carolina; it has been extirpated from Delaware and Pennsylvania (United States Fish and Wildlife Service 1995). The largest number of occurrences is in Virginia, where it is known from six river systems: Potomac, Rappahannock, Mattaponi, Pamunkey, Chickahominy, and James. In North Carolina it is known only from disturbed habitats such as roadside ditches and wet fields; these populations apparently do not persist over time (United States Fish and Wildlife Service 1995, Ware 1991). Thus, the southernmost stations for the plant in natural habitats are on Virginia's James and Chickahominy Rivers.

Surveys for A. virginica were conducted on the James River in 1995, 1996, 1998, 2000, and 2001 by the authors with assistance from Robbie Barbuto, David Boyd, Phil Coulling, Kathy Derge, Sandra Erdle, Holly Grubbs, Kevin Heffernan, Steve Killeffer, Rick Myers, Tom Smith, John Townsend, Leslie Trew, Luther Vick, Dean Walton, Joe Weber, and Irv Wilson. Suitable tidal marsh habitat was systematically checked from Jones Neck (10.5 km southeast of Richmond) downstream to Jamestown Island; this included the James River proper and the following tributaries: Fourmile Creek, Turkey Island Creek, Appomattox River, Powell Creek, Queens Creek, Kittewan Creek, Kennon Creek, Powhatan Creek, Back River, Grays Creek, Crouch Creek, and Timber Neck Creek. Garrie D. Rouse, under contract with the Virginia Department of Conservation and Recreation, conducted surveys for A. virginica on Herring Creek and Upper Chippokes Creek in 1995 (Rouse 1995).

The surveys were conducted each year between mid-August and mid-October. The reproductive phases of A. virginica generally occur within this time period. Most surveys were conducted by motorized johnboat. Fieldwork was planned to coincide with high tides, which allowed the johnboat to travel closer to the marsh edge and further up tributary creeks, thus giving the surveyor better visibility. While visibility into the interior of the marshes was usually good, in some cases it was hampered by dense stands of tall perennial grasses such as Spartina cynosuroides (L.) Roth and Zizaniopsis miliacea (Michx.) Doell & Aschers. Thus, not all potential habitat could be surveyed with this method.

Survey work included checking seven previously reported locations for the rare legume on the James River. A.B. Massey collected the plant in the vicinity of Jordan Point on the south side of the river (Prince George County) in 1937 [(s.n.)(VPI!)] and in 1939 [(s.n.)(VPI!)]; M.L. Fernald and B. Long collected it there in 1938 (Fernald 1939). Fernald and Long collected the plant across the river from Jordan Point near Harrison Point (Charles City County) in 1939 (Fernald 1940). In 1936, E.O. Erlanson collected the plant on the north side of the river (Charles

City County) at Wilcox Wharf [176 (NA!)]. Sensitive joint-vetch was collected along Kitte wan Creek (Charles City County) by Fernald and Long in 1939 (Fernald 1940) and by T.F. Wieboldt in 1985 [5922 (VPI!)]. In 1938, Fernald and Long collected the plant at the mouth of Crouch Creek (Surry County) on the south side of the river (Fernald 1939). Massey collected the plant on the north side of the river just upstream from the mouth of Powhatan Creek (James City County) in 1938 [2059 (VPI!)]. Finally, A. virginica was collected along Back River opposite Jamestown Island (James City County) by Fernald and Long in 1938 (Fernald 1939) and 1939 [11052 (US)].

Aeschynomene virginica was found at only two of these seven locations during the course of our 1995-2001 survey work. On 25 September 1996, 40-50 plants were seen in an extensive tidal freshwater marsh along Kittewan Creek within a 5.0 by 20.0 m area. On 7 September 2000, four plants were seen at this same station along Kittewan Creek, and one additional plant was seen at a second station located 0.2 km downstream. Thirteen plants were found within a 6.0 by 2.5 m area along Back River on 18 October 2000 within an extensive oligohaline marsh. During a search the following year, no plants were located. The remaining five historical locations for A. virginica on the James River have been degraded to various extents by shoreline stabilization activities (including the use of riprap, seawalls, and jetties), pier construction, bridge construction, and/or commercial and residential development. Only remnants of marshes were found at these locations.