Forked three-awned grass (Aristida basiramea) COSEWIC assessment and status report: chapter 4

Distribution

Global Range

Aristida is a tropical to warm-temperate genus of 250-300 species. It grows mostly in dry grasslands and savannahs, sandy woodlands, pine barrens; also on rocky hills and highlands, rocky slopes and mesas, and in the mountains to elevations of 3500 metres; in arid deserts, and in open weedy habitats (Henrard, 1929; Allred, 2001).

Aristida basiramea is endemic to North America, with a range that is primarily mid-western, with outliers west to Colorado, south to Texas, east to Maine, and north as far as the Upper Peninsula of Michigan (see Figure 2). In North America it grows in open, sandy, often barren ground (Allred, 2001). Its global rank is G5, defined as “Secure – Common, widespread, and abundant (although it may be rare in parts of its range, particularly on the periphery). Not vulnerable in most of its range. Typically with considerably more than 100 occurrences and more than 10,000 individuals.” (NatureServe, 2001).

Figure 2. Global distribution of Aristida basiramea (updated from Reznicek, 1984).

 Global distribution of Aristida basiramea

Canadian Range

The native Canadian range is restricted to southern Ontario and southern Quebec, where A. basiramea is known from a total of five extant native populations (Figure 3). One of the Ontario populations supported a sub-population that is now believed extirpated. No historical stations are known for the species, since the 1862 and 1954 records from Ontario, and the 1888 and 1927 reports from Manitoba, have been deemed to be erroneous (see Erroneous Reports).

The extent of occurrence in Canada totals 502 sq kms. The trend in extent of occurrence is unknown since 1975, with insufficient comparative data for the five extant populations, three new populations discovered in 2001, and with one of these soon to be heavily developed.

Figure 3. Native Canadian distribution of Aristida basiramea (adventive Rainy River District site not mapped).

Native Canadian distribution of Aristida basiramea

Extant Populations

Fieldwork was conducted on the Ontario and Quebec sites in 2001 and 2002. In addition, searches were carried out unsuccessfully in Ontario by the author on 16 August 2001 in suitable habitat in the area east of Awenda Provincial Park, from Toanche, through to Marygrove, and northwest along the sand road to Sawlog Bay. Habitat certainly appeared to be suitable at a couple of sand barren sites in this area, with Danthonia spicata dominant. As well, unsuccessful searches were carried out for this report in sand barrens in Oro-Medonte Township and in Springwater Township. Habitats similar to the Cazaville station exist in two other areas in Quebec, Oka and Mirabel, but these areas are located further north, and the Oka site has been intensively botanized over the last ten years. The probability of finding new populations is thus believed to be quite low (Coursol, pers. comm. 2003).

Figure 4. Close-up of Aristida basiramea at Cazaville. October 2001 (photo by Frédéric Coursol).

Close-up of Aristida basiramea at Cazaville

Figure 5. Aristida basiramea habitat on the Montée Cazaville. October 2001 (photo by Frédéric Coursol).

Aristida basiramea habitat on the Montée Cazaville

Ontario

Macey Lake – Tiny Township, Simcoe County. Discovered by A.A. Reznicek on 20 August 1975, north of Penetanguishene in “dry, bare sand in full sun in a sandy barren area between road and young pine plantation with Carex rugosperma, Panicum depauperatum and Sporobolus cryptandrus”. It was noted as being “Widely scattered and sometimes frequent in the most open areas”. This population was observed in 1995 by A.A. Reznicek, M.J. Oldham, D.A. Sutherland, and G.M. Allen, and was noted by Oldham as “locally abundant”.

Surveyed on 16 August 2001 by G.M. Allen and T. Tully. Main population on level disturbed, dry, loose fine to coarse sand along south shoreline of lake at base of old shoreline Lake Algonquin dunes in association with Danthonia spicata, Panicum implicatum, Carex merritt-fernaldii, Setaria viridis, Agrostis gigantea, Plantago lanceolata, Echium vulgare, Rubus allegheniensis, Centaurea maculosa, andPolytrichum sp. On a previous observation in 1995 the species was restricted to the slopes of the old shoreline (Reznicek et al.), but since then the species has moved to the areas disturbed by a peat mining operation, which ceased in 1995. Thousands of plants in a 200 X 60 metre area, with densities in places of a couple of hundred per square metre. Collected (TRTE) and photographed by G.M. Allen (Figures 6, figure7). Privately owned.

Figure 6. Aristida basiramea core population at MaceyLakeon disturbed shoreline. 16 August 2001.

Aristida basiramea core population at MaceyLakeon disturbed shoreline

Figure 7. Aristida basiramea habitat on old shoreline at MaceyLake. 16 August 2001.

Aristida basiramea habitat on old shoreline at MaceyLake

Christian Island – Village of Christian Island, Beausoleil First Nation, Tiny Township, Simcoe County. Discovered by A.A. Reznicek on 26 August 1981 on Christian Island First Nations Reserve in “dry, open sand barrens with Sporobolus cryptandrus and Cyperus filiculmis” (the latter is now called Cyperus lupulinus), and was noted as “frequent (60 to 80 plants?), locally a dominant in areas of more or less bare sand”.

The above station, which had been identified precisely on a topographic map by A.A. Reznicek and filed at the ONHIC, was searched for unsuccessfully 9 September 2001 by G.M. Allen, T. Tully, B. Bowles & J. Goltz, and is believed to be extirpated due to either infilling of single family dwellings, succession of the “small area of bare sand”, or both. The investigators continued their search to the northwest of Reznicek’s station and found Aristida basiramea only 500 metres distant. In correspondence with Reznicek, it is believed that the colony observed by Reznicek in 1981 was likely larger in extent and more scattered than he had realized, and he did not search the barrens associated with the baseball diamond, which was present in 1978, as observed in air photos.

Village of Christian Island, Beausoleil First Nation, Tiny Township, Simcoe County. Surveyed on 9 September 2001 by G.M. Allen, T. Tully, B. Bowles & J. Goltz. Tens of thousands of plants in open sand over 200 X 50 metre area, and most common in open areas with little competition. Dominant associates are Danthonia spicata, Rumex acetosella, Poa compressa, Panicum linearifolium, Carex muhlenbergia, Rudbeckia hirta, Solidago nemoralis, Carex merritt-fernaldii, Agrostis gigantea, and Polytrichumsp.

The site is believed to be located on the post-glacial Nipissing shoreline. Site succeeding to old field with Rhus typhina at edges. Collected (TRTE) and photographed by G.M. Allen (Figure 8). Ownership by Beausoleil First Nation.

Figure 8. Aristida basiramea station at Christian Island. 9 September 2001.

Aristida basiramea station at ChristianIsland, 9 September 2001

Beausoleil Island – Georgian Bay Islands National Park, Georgian Bay Township, Muskoka District.

Discovered by Allan Sinclair and Jim Goltz on September 12, 2001. Over 500 plants of Aristida basiramea in an open sandy field on Beausoleil Island. The plants were mostly found in two main concentrations but occasional plants were found elsewhere. The plants were found growing in dry open sandy areas with Panicum sp., Rumex acetosella, Polytrichumsp., Asclepias syriaca, Solidago nemoralis, Lecheaintermedia and Cladonia sp., and grew best where there was little or no competition. The plants were found at two different levels of the old beach shoreline, which is believed to be of Nipissing age, i.e. 4,000 to 6,000 YBP. Collected by J. Goltz (TRT, MICH) and photographed by A. Sinclair. Ownership by Parks Canada.

Anten Mills – Northwest of Barrie in the Village of Anten Mills, Springwater Township, Simcoe County. Discovered 7 October 2001 by G.M. Allen south of the village of Anten Mills where A. basiramea was very occasional along edge of the Algonquin Shoreline. Primary population consists of ca. 500 plants in remnant Danthonia spicata sand barren community occupying 10 metres X 3 metres. Other prevalent associates are Panicum implicatum, Rumex acetosella, Pteridium aquilinum, Sporobolus cryptandrus, Poa compressa, Agrostis gigantea, Cyperus lupulinus, Asclepias syriaca, Verbascum thapsus, Hypericum perforatum, Carex brevior. Site is quickly succeeding in with Rubus strigosus, Pinus sylvestris, and Rhus typhina, and Aristida basiramea is restricted to open, lightly used tote roads and verges. Two additional sub-populations of a few hundred plants each, and another sub-population of approximately 100 plants were. These sub-populations are quite proximal to the main population, with none more than 0.5 kms distant. Collected (TRTE) and photographed by G.M. Allen (Figure 9). Privately owned.

Figure 9. Aristida basiramea remnant habitat amongst conifer plantations on Algonquin Shoreline at Anten Mills. 8 October 2001.

Aristida basiramea remnant habitat amongst conifer plantations on Algonquin Shoreline at Anten Mills

Rainy River District – Discovered on 18 August 2001 by M.J. Oldham and W.D. Bakowsky ca. East of Fort Frances, near Swell Bay, Rainy Lake. Locally common for ca. 50 m along sandy/gravelly roadside. Noted by Oldham as probably adventive at this site, as plants only on roadside. Collected by M.J. Oldham (MICH, DAO, and NHIC).

Quebec

Cazaville (Near the Town of) - Discovered for Quebec by Dr. Jacques Brisson on 20 September 2001 from a sand plain near the Town of Cazaville, municipality of Saint-Anicet, Le Haut-Saint-Laurent M.R.C., close to the USA border. In October 2001, Frédéric Coursol, accompanied by A. Meilleur, visited the site and surrounding area. They documented 6 sub-populations around Cazaville in an area of less than 1 km². In October 2002, Coursol again visited the area, concluding that there were 11 sub-populations supported, totalling an estimate of more than 10,000 plants. This population seems to be indigenous since a good part of it occupies a natural sand barrens environment, located on a post-glacial shoreline, where other provincially rare plants are found. The Aristida has also invaded disturbed sandy openings on the periphery of the site, including old fields and roadside ditches. Danthonia spicata was prevalent at the station, with prevalent associates being Poa compressa, Agropyron repens, Rubus alleghaniensis, Cyperus houghtonii, Cyperus lupulinus subsp. macilentus. Collected by F. Coursol and deposited at MT. Verified by Stuart Hay. Photographed by F. Coursol (Figures 4, figure5). Private ownership by hundreds of different people.

Population counts/estimates for 6 of the 11 sub-populations at Cazaville, as recorded by F. Coursol October 2001, are as follows:

  • Montée Cazaville >1000 plants
  • Montée Smith <100
  • Ridge Road >1000
  • Montée Currie : 300
  • Montée Currie : 200
  • Montée Cazaville : 500 to 1000
  • Approximate total estimate for all 11 sub-populations: >10,000

Erroneous Reports

There is a report on file at the Ontario Natural Heritage Information Centre (ONHIC) indicating an 1862 collection of A. basiramea from Hamilton. The information is based upon label data taken from an Ontario Ministry of Natural Resources (OMNR) Central Region Rare Species Mapping Project Data Sheet (Riley et al., 1992), which states “Hamilton, at the beach” and “in water at beach”. There was no abundance or exact locational data noted with the record, and the population is believed by the ONHIC to be erroneous (pers. comm. M.J. Oldham 2001). Such a herbarium sheet was never observed by A.A. Reznicek, when preparing the map for Argus & Keddy (1984).

The record made in 1954 by J.M. Cruise from Long Point, “in dry beach dune 2.7 km west of the lighthouse”, was rejected based on “label error” by Reznicek in 1984 when compiling the Rare Plant Atlas, and by Reznicek and Catling in their Flora of Long Point (1989). It was reported by Cruise at the time under the name Aristida intermedia (Cruise, 1969), and was the only collection ‘known’ from Ontario until Reznicek’s discovery north of Penetang in 1975. Cruise’s record never seems to have been observed post-1954.

Aristida basiramea has been reported from Manitoba (Macoun in 1888, Shimek in 1927); however, both the Flora of Manitoba (Scoggan,1957) and the Flora of Canada (Scoggan, 1978-1979) exclude the species from the Manitoba flora. Given the age of the reports, the likelihood of misidentification, and the fact that they have never been confirmed, the Manitoba Conservation Data Centre will be updating their species rank from SU (status unknown) to SRF (reported falsely) (Greenall, pers. comm. 2003).

Page details

Date modified: