Prototype quillwort (Isoetes prototypus) COSEWIC assessment and status report: chapter 4

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Distribution

Global range

Following the 1988 discovery of I. prototypus in New Brunswick at site 10, the global range of this species was determined by D.M. Britton through the examination of herbarium specimens. As some of these records were nearly a hundred years old, all locations were subsequently visited by D.M. Britton and/or D.F. Brunton for confirmation that I. prototypus was still extant there and additional lakes were surveyed for this species. As of 2002 it was known to be present in 7 lakes throughout the world, all in northeastern North America.

1 lake in New Brunswick, Canada

• Site 10 (York County)

5 lakes in Nova Scotia, Canada

• Site 1 (Cape Breton County)
• Site 6 (Annapolis County)
• Site 7 (Annapolis County)
• Site 4 (Cumberland County)
• Site 3 (Colchester County)

1 lake in Maine, U.S.A.

• Site 13 in Acadia National Park (Hancock County)

During fieldwork undertaken in 2003 for the purpose of this status report and additional fieldwork in 2004, I. prototypus was observed in situ in all previously known sites, as well as being discovered in four additional lakes in Nova Scotia and two additional lakes in New Brunswick (Figure 7). Isoetes prototypus was discovered at site 12 in flotsam by Dwayne L. Sabine and Mary E.J. Sabine on 5 June, 2004.

New Nova Scotia locations

• Site 2 (Cape Breton County)
• Site 5 (Cumberland County)
• Site 8 (Digby County)
• Site 9 (Digby County)

New New Brunswick locations

• Site 11 (Queens County)
• Site 12 (York County)

All Nova Scotia and Maine lakes where this species occurs are within 10 to 15 km of the Bay of Fundy / Gulf of Maine coast / Cabot Strait. The New Brunswick lakes where it has been found are much further inland from the ocean, ranging from approximately 35 to 180 km. from the Bay of Fundy.

Canadian range

As indicated above, 12 of the 13 known locations for I. prototypus occur in Canada, nine in Nova Scotia and three in New Brunswick. In Nova Scotia I. prototypus is known to occur in five counties, from the northeastern to southwestern ends of the province, but only in a few select locations. In New Brunswick, it is known from three disparate sites spanning nearly one-half of the length of the province. The combined total surface area of all lakes in which I. prototypus occurs is quite small (~ 961 ha). The known Canadian populations of I. prototypus occupy a total estimated area of about 2.5 ha and is likely less than 5 ha, including portions of populations that might possibly have been missed. The range of the species in Canada has an extent of occurrence of <<5000 km². A map of all sites surveyed for I. prototypus in 2003 and 2004 is shown Figure 8.