Small-flowered lipocarpha (Lipocarpha micrantha) COSEWIC assessment and status report: chapter 4

DISTRIBUTION

Global range

Lipocarpha micrantharanges from Brazil in the south to the Canadian populations in the north, occurring throughout Central America (for references refer to Sabourin et al. 1992).  North of Mexico, the main range extends from Texas, north to Northwestern Ontario, and east to the American East Coast.  Disjunct populations are found in Florida, California, British Columbia, and elsewhere as shown in figure 2 (Tucker in press).

Figure 1. Lipocarpha micrantha, approximately 1.2x lifesize.  Photo by Al Harris.

Figure 1. Lipocarpha micrantha, approximately 1.2x lifesize.  Photo by Al Harris.

Figure 2.  Distribution of Lipocarpha micrantha in North America north ofMexico(Extant Canadian occurrences are found in north-western Ontario (stippled area) and south-central British Columbia (solid circle); the historic Quebec population (solid circle) is extirpated). 

Figure 2.  Distribution of Lipocarpha micrantha in North America north ofMexico(Extant Canadian occurrences are found in north-western Ontario (stippled area) and south-central British Columbia (solid circle); the historic Quebec population (solid circle) is extirpated). 

Canadian range

Lipocarpha micrantha has an extremely fragmented distribution in Canada, as shown in figure 3a and figure 3b.  Of seven documented populations (Ceska and Ceska 1982, Oldham and Crins 1988, Sabourin et al. 1992, Oldham 1996, Oldham 2000 Harris et al. 2000, only 3 persist.

Figure 3a.  Distribution of Lipocarpha micrantha in Ontarioand Quebec.  Solid circle marks population located in 2001.  Squares mark extirpated populations (two in Ontario, one in Quebec).  The triangle marks the Pound Net Bay, Rainy Lake population discovered in 2000.

Figure 3a.  Distribution of Lipocarpha micrantha in Ontarioand Quebec.  Solid circle marks population located in 2001.  Squares mark extirpated populations (two in Ontario, one in Quebec).  The triangle marks the Pound Net Bay, Rainy Lake population discovered in 2000.

Figure 3b.  Distribution of Lipocarpha micrantha in British Columbia.  Solid circle marks population located in 2001.

Figure 3b.  Distribution of Lipocarpha micrantha in British Columbia.  Solid circle marks population located in 2001.

Two extant populations of Lipocarpha micrantha were located in Canada in 2001.  One population is at Lake Osoyoos, in the Okanagan Valley, British Columbia.  The other population is on Sable Island, Lake of the Woods, in Northwestern Ontario. A third population was oberved in 2000 at Pound Net Bay, Rainy Lake in Northwestern Ontario.  As will be discussed below, Lipocarpha micrantha may persist in the seed bank at Pound Net Bay.

Four other populations of Lipocarpha micrantha have been reported in the past, but they have been extirpated.  The population at Missisquoi Beach in Southern Quebec was last documented in 1957, and has not been relocated since (Labrecque, pers. commun., 2001).  The population at Holiday Beach in Southwestern Ontario was last reported in 1987and wasn’t located in 2001.  Several historic records of Lipocarpha micrantha from the Detroit River, circa 1900, have not been relocated since, despite search efforts in the 1980’s.  A second Lake Osoyoos population was documented in 1978, but had been extirpated by 1985 (Sabourin et al. 1992).  The habitat at this location was destroyed by the development of a recreation area.

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