Water Chestnut (Trapa natans L.) Infestation in the ... - SUNY Oneonta

FIGURE 1. The distinguishing rosette (1), nut (2), leaflet showing buoyancy bladder (3)
and root stalk with filiform rootlets (4) of T. natans. Modified from
http://aquat1.ifas.ufl.edu/tranatdr.jpg
Distribution
Water chestnut is native to the warm temperate regions of Eurasia and North
Africa. There is some discrepancy in the literature as to which decade Trapa natans first
entered the U.S., and when it became established. Naylor (2003) states water chestnut
was first recorded in North America near Concord, Massachusetts in 1859. Hummel and
Findlay (2006) state that it was first introduced to the U.S. in 1875, while Pemberton
(1999) states it was first observed in 1884, growing in Sanders Lake, Schenectady, New
York.
Populations have become established in many locations in the northeastern United
States, including the Hudson River, Lake Champlain and six of its tributaries, the Nashu
River in New Hampshire and the Connecticut River in Connecticut. The plant has also
been documented in Delaware, Maryland, Massachussets, Pennsylvania and Virginia
(Pemberton 1999) (FIG 2).
Trapa also thrives in the Great Lakes Basin, the Oswego River, Oneida Lake, and
the Erie Barge Canal System (Pemberton 1999). In 1998, water chestnut was found in the
South River in Quebec, which is connected to the Lake Champlain outlet via the
Richelieu River. Its spread has continued because of the suitability of habitat. In 2001,
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