Potamogeton crispus

History of Spread

Potamogeton crispus (Curly Pondweed) is widespread in the Old World, in Eurasia, Africa, and Australia, but it is clearly introduced to North America (Stuckey 1979). Unconfirmed reports (probably misidentification of P. richardsoni) are recorded from North America as early as 1814, but the first definite records and herbarium specimens were collected by Tatnall (1860) from the Delaware River. Its spread was rapid: by 1900 it ranged south to James River VA and west. to Lake Erie; north to Lake Champlain and M. By 1930, it occurred in all the Great Lakes and the upper Mississippi Basin, and by 1960, in the Rocky Mountain States. There was a southward expansion in the 1930s-40s: reaching NC in 1950; FL in 1937; LA in 1949, but the southern spread was slow and spotty (Stuckey 1979).

By the 1970s, P. crispus was also found through southern Canada (Catling and Dobson 1985). Potamogeton crispus was spread both by waterfowl and by deliberate planting as a wildlife food. It was probably introduced separately to CA, in about 1900, where it spread into the Sacramento-San Joaquin system in the 1940s-1950s (Stuckey 1979). It occurs in fresh-oligohaline regions of major Atlantic estuaries from Chesapeake Bay to the St.Lawrence, including the Hudson River (Mills et al. 1997;Stuckey 1979).

Chesapeake Bay records are summarized below:

James River- Potamogeton crispus was present by 1900 (Stuckey 1979), but was not included in recent submerged aquatic vegetation surveys (Orth et al. 1993).

Potomac River- Potamogeton crispus was first collected in Alexandira VA in 1876, and was abundant by 1916 (Haramis and Carter 1983). In 1978-81, it was found only in middle portion of estuary, Maryland Point to Machadoc Creek, where it was common, but not dominant (Haramis and Carter 1983; Carter et al. 1984). It was common at oligohaline Brent Marsh, Stafford County VA (Strong and Kelloff 1994); and in a 'slightly brackish marsh', Caledon Natural Area, King George County VA (Simmons et al. 1995).

Patuxent River - Potamogeton crispus was common near Jug Bay in 1992 (Orth et al. 1993).

Upper Bay and Tributaries- Potamogeton crispus was first collected in Galena MD in streams (1877), and then at Sesputie Island (1879) (Stuckey 1979), the vicinity of Baltimore; Sollers (1888), the Chester, Sassafras Rivers, where it was abundant (Shreve et al. 1910). A specimen was collected from Herald Harbor in the Severn River in 1917 (Stieber 1967). Later, P. crispus was present but not dominant on Susquehanna Flats (Bayley et al. 1978). In 1991-1992 surveys, scattered records were found in the Northeast, Bush, and Gunpowder Falls Rivers (Orth et al. 1993).

History References - Bayley et al. 1978; Carter et al. 1984; Catling and Dobson 1985; Haramis and Carter 1983; Mills et al. 1997; Orth et al. 1993; Shreve et al. 1910; Simmons et al. 1995; Sollers 1888; Strong and Kelloff 1994; Stuckey 1979; Tatnall 1860.

Invasion Comments