Large twayblade, Liparis lilifolia, in Canada and New York

Holly Bickerton, a Canadian biologist, is preparing the Canadian COSEWIC (Committee on the Status of Endangered Wildlife in Canada) status report update for large twayblade, Liparis liliifolia (S2 for ON, S1 for QUE), also a state endangered orchid in New York.

She reports that since the last status report in 1998, eight new occurrences have been discovered in Canada (for a new total of 19 extant occurrences, a substantial increase), with a significant range movement to the north and east. Large new populations have recently been documented near Kingston, ON, and north of Montreal. Previously, the species Canadian range was believed to be near Toronto. Interestingly, the Kingston occurrence is from a red maple swamp growing on sphagnum hummocks, which is a new habitat type for Canadian populations, but is not uncommon in NY. This opens up a lot of potentially suitable habitat in such swamps, across eastern Ontario and western Quebec.

Before the early 1990s the plant was known from the Hudson Valley as far north as Albany County. Then in 1992 and 1994 it was discovered in central New York near Syracuse and along Lake Ontario. Both of these occurrences were on hummocks in red maple hardwood swamps, just a few plants each. Since then we have not found any new occurrences to the north. Our largest occurrence is in a red maple hardwood swamp down in Ulster County. We should be searching more red maple swamps along the Great Lakes and into the Adirondacks to see if populations are expanding north as they are in Canada.

Explore posts in the same categories: Plant Identification, Rare Plant Surveys

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