Prepared by Christine Hanrahan with Stephen Darbyshire

on behalf of the Conservation Committee of the Ottawa Field-Naturalists’ Club

November 1998

For Submission to the Regional Municipality of Ottawa-Carleton



The Petrie Islands lie close to the South shore of the Ottawa River within the Township of Cumberland. Although designated by the Ministry of Natural Resources as Provincially Significant Wetland and as an Area of Natural Significance, and also having similar Regional recognition and being owned by the Region, the Islands are the subject of both Regional and Municipal development consideration. In this brief the Ottawa Field – Naturalists’ Club describes the ecology, plant and animal life of these islands, objects to plans for their development, and outlines measures that would protect their ecology while allowing passive recreational uses similar to those proposed by the Friends of Petrie Island,

  1. I.     Introduction: Ecology of the Petrie Islands

    The Petrie Islands lie close to shore in the Ottawa River within the Township of Cumberland. These islands are a series of alluvial deposits forming a wetland complex of elongate sedimentary ridges and backwaters characteristic of the Ottawa River below the confluence with the Gatineau River. Along with Kettle Island and the Duck Islands, Petrie Islands form a unique landform in the region chronicling the powerful geological forces which shaped the face of our country. The sand and clay sediments that make up these islands were created by the massive ice – sheet that ground and polished the continent 10,000 years ago. Crushed by the continental glaciers from the rocks further north, the sediments were carried down the Ottawa and Gatineau Rivers. The river became a major route for plants and animals moving into Canada after the glaciation. Fine sediments would have provided the closest thing to soil available on the denuded landscape. From the patterns of plant distribution we can still see the effects of these processes today.

    The unique habitats of the river corridor contain many plant species which reached their migrational limits along the flood plain forests and shores. Many species of plants can only be found in the region along the flood plain of the Ottawa River. Some of these plants require water systems and flooding for their seeds to be dispersed. Some need the continual shifting of shoreline sediments, while others need their habitat to be inundated in the spring but dried out in the fall. All of the plant communities found on the Petrie Islands are specially adapted to extensive spring flooding.

    The power of the river and its seasonal fluctuations have shaped these islands and made them a special habitat for plants and animals. The islands are almost completely flooded in the spring. Flooding of the forests on the islands is a special feature that many species are adapted to and may even require to maintain healthy populations. Continual erosion and deposition of sediments around the islands provides a renewal of shoreline habitats and an evolution of plant and animal communities. The quiet backwaters are extremely rich habitats providing shelter and abundant nutrients for a wide variety of plants and animals not found in the open river. The diverse mosaic of habitats, high energy river shores, seasonally flooded forests, quiet backwaters, sand dunes, fertile clay soils, are all formed from the same processes, unique in the region to the Ottawa River. It is this variety of habitat that supports the many plants and animals of Petrie Islands.

    At one time the types of habitats and communities found on Kettle Island, the Duck Islands and Petrie Islands would have been common along much of the Ottawa River shores between Ottawa and Montreal. Today, flooding and water level control from hydroelectric projects, development, shoreline armouring and farming have transformed the flood plain habitats. The natural environment of the shores, forests, and backwaters along the Ottawa River has all but disappeared and is long past regeneration, apart from a few areas such as the Petrie Islands. (Written by Stephen Darbyshire)

    II.    The Future of the Petrie Islands

Land – use Designation of Petrie Islands

The Petrie Islands are owned by the Regional Municipality of Ottawa-Carleton and are within the Township of Cumberland. The wetland complex, which covers most of the islands, has been designated by the Ontario Ministry of Natural Resources (OMNR) as Provincially Significant Wetland as well as an Area of Scientific and Natural Interest (ANSI). The Regional Official Plan designates most of the islands and the shoreline as Provincially Significant Wetland, while the small areas of high land and the sand extraction operation are designated Waterfront Open Space. The north side of the North Service Road on the mainland is listed as General Urban Area in the Official Plan – Schedule B. The Regional Official Plan acknowledges the importance of protecting the islands’ natural environment for wildlife, particularly waterfowl, and for the significant plant species onsite. The plan also recognizes the value of the islands for outdoor recreation. Under Cumberland’s Official Plan, the islands are designated Open Space, with no recognition of their provincial and regional status as significant wetlands. Cumberland recognizes the potential for both passive and active recreation on the site, and notes the conservation values of the area.

Development Plans

The Township of Cumberland has prepared a ’Petrie Islands Master Plan’ (1998) delineating their vision for the future of this site. Their plan would divide the islands into passive and active recreation areas, The passive recreation portion would include several large picnic areas and nature trails, while the active recreation section would be the site of the proposed marina complex. This complex could include amongst other features, an amphitheatre, club house, restaurant and large parking areas.

The islands are also viewed by the Region and by Cumberland as a potential site of the much-discussed new bridge across the Ottawa River. While a bridge may at first glance seem to be less destructive of the natural environment than a marina complex, in reality bridge development brings its own set of disruptive forces which can wreak long-term degradation on the site.



The Petrie Islands represent one of the few remaining scraps of natural habitat left along the river between Ottawa and Montreal that is close to an original state. We are concerned that Cumberland Township has not recognized the provincial significance of the Petrie Islands wetlands, and appears to place both active and passive recreation before conservation. We would like to encourage the Township to bring its designations into line with those of the province and the region. Compromising the fragile natural characteristics of the Petrie Islands with development and/or construction will result in the loss or degradation of an irreplaceable part of our heritage. Therefore, the Ottawa Field-Naturalists’ Club objects to the proposed Marina complex and any other large or small scale commercial development, as well as the proposed bridge across the Ottawa River   at Petrie Islands.


Passive Recreation

The best option would be to leave the islands as they are, with no further interference. However, if changes are to occur, we believe that the next best choice is using the area for passive recreation such as nature study, hiking, picnics and swimming, as defined by the Friends of Petrie Island (1998). Increased usage by humans brings its own set of problems and a degree of supervision will be required if the natural values are to be protected. Certain ecologically sensitive areas of the islands should be protected from excessive human intrusion, These areas include turtle and bird nesting areas, and other key wildlife habitats, and locations of significant plant species. Such areas would be identified during thorough wildlife inventories of the islands. Great care should be taken in locating new trails and the areas should be assessed first to determine whether the trails will. have a negative impact on wildlife usage. During the summer breeding season, birds are particularly vulnerable to disturbance, especially those species which nest in low shrubs or on or near the ground. We believe that scouting the area first with a knowledgeable naturalist will alleviate most of these problems.


New trails should be just wide enough to allow easy movement, but not as wide as the recreational trails in the region which are approximately 12 feet in width. We prefer to see the trails remain grassed or otherwise natural, emulating the majority of the NCC Greenbelt trails, rather than overlaid with hard material. However, we also recognize that in some situations an artificial surface may be necessary, for example when a trail receives such heavy use that the vegetation wears away leaving a bare or muddy surface which users may skirt around inadvertently widening the trail, sometimes to a considerable width, and destroying adjacent vegetation. Wood chips (or bark mulch), while a ’natural’ material are not suitable for use on the islands because the fast flowing spring floods would quickly remove them. Stone aggregate materials or local limestone stepping stones in muddy places provide a durable and long-lasting alternative to paving which we feel is too intrusive in a natural setting. On the whole, we believe that the annual flooding of the islands would have negative effects on any surfacing material, even paving. Therefore, we reiterate that our preference is for natural trails, with the occasional cutting or brushing out to keep them open.


Interpretative signage and brochures

Interpretive signage at the trail-head as well as judiciously placed along the nature trails will help visitors understand the unique environment of the Petrie islands. Information can be given on such aspects as the formation of the islands, significant plant species (e g the hackberry trees), and wildlife usage. A brochure on the natural history of the islands can be carried by visitors as they traverse the trails, helping teach the special significance of the area. Alternatively, an interpretive trail guide brochure highlighting significant features along the trail can be produced, along with brochures on the birds and the plants of the Petrie islands. The Conservation Committee of the Ottawa Field-Naturalists' Club is willing to assist the RMOC and the Friends of Petrie island with these suggestions.


III.     Flora and Fauna of the Petrie Islands

No list of flora or fauna is ever complete and that is certainly true of the data supplied with this document. We consider the attached lists preliminary and stress that further work would produce a substantial increase in plant and animal species observed.

A. Plants of the Petrie islands

The forested portions of the islands, containing a variety of trees about 60 - 80 years old, were divided into 6 zones by Dugal in 1977. Mature specimens of butternut (Juglans cinerea), bitternut hickory (Carya cordiformis), basswood (Tilia americana), red ash (Fraxinus pensylvanica) black ash (F. nigra), and hackberry (Celtis occidentalis) observed during the 1977 survey, still remain along with hybrid silver/red maples (Acer saccharinum x A A. rubrum).
A thorough survey of the flora of this area has yet to be carried out, but the preliminary list compiled by Albert Dugal in 1977, with additions by Stephen Darbyshire in the 1980's and 1990's, by Dan Brunton during the same time frame, and casual observations by others during 1998, has resulted in an impressive list of plants (Appendix A). Of special interest is the extensive stand of hackberry which Dugal (1977) calls the "greatest known the Ottawa district." Two plant species found on the islands are considered of provincial significance. One of these, Gattinger's Panic Grass (Panicum gattingeri) is known within the region only on Petrie Islands (Brunton 1998). Petrie Islands is also the only currently known location in the RMOC for the regionally rare Mossy Love Grass (Eragrostis hypnoides) (IBID).

Our preliminary list shows twenty-nine significant plant species occurring on the Petrie islands. Significant species are those regarded as regionally or provincially rare or sparse. Rare is defined as "3 records or less" by Gillett and White (1978), and "5 or fewer contemporary populations, (post 1969)" by Brunton (1998). Sparse is defined as "4 to 12 records" by Gillett and White, and "6 to 10 contemporary populations (post-1969)" by Brunton. Many other plants found on the Petrie islands are considered regionally uncommon, defined by Gillett and White as "not often found even in suitable habitats, usually in small numbers, more than 12 records". We have listed only those native species identified as regionally significant by Gillett and White, and Brunton, at the end of Appendix A.

B. Birds of the Petrie islands

A comprehensive survey of the avifauna of the Petrie Islands has not yet been conducted. However, between 1994 and 1998, Tony Beck recorded his sightings of birds during this period, and his data together with sightings by several other naturalists have combined to produce a list of 109 species observed to date.
It is no surprise that the diversity of habitat attracts an equally diverse number of birds. The extensive wetlands, backwaters and the Ottawa River shoreline provide habitat for birds such as pied-billed grebe, American bittern, great blue heron, American coot, and a variety of waterfowl, shorebirds, gulls and terns, belted kingfisher, and red-winged blackbird. The woods and shrubby thickets host woodpeckers such as the large pileated woodpecker, flycatchers, black-capped chickadee, house wren, thrushes, vireos, warblers, rose-breasted grosbeak, and purple finch. Edges and open areas are used by various sparrow species, American goldfinch, gray catbird and brown thrasher. All six species of swallows found in the Ottawa area have been observed on the Petrie Islands. A complete list of all birds observed is provided in Appendix B.

Bird usage is greatest during the spring and fall migrations when flycatchers, thrushes, flocks of warblers, and a variety of other birds use the area as a stopover point for resting and feeding. Many birds also find the quiet woods and backwaters conducive to nesting, and a breeding bird survey of the islands would be useful in determining more precisely the number of nesting birds. Winter sees the fewest birds, but year-round residents such as black-capped chickadees and downy woodpeckers are sometimes joined by winter visitors such as evening grosbeak, snow bunting, and in one recent winter, a great gray owl. In the cold months, many birds move from one area to another foraging for food, and it is during this time of year that birds such as great horned owls may be found along with small flocks of overwintering birds from adjacent areas.

C. Butterflies of Petrie islands

Surveys specifically targeting butterflies have not been conducted and the butterfly list (Appendix C) consists entirely of casual observations by naturalists Joyce and Allan Reddoch, Christine Hanrahan, David Hobden, and especially Peter Hall who contributed 50 % of the sightings. Twenty-two species have been recorded to date.

D. Mammals of Petrie islands

The list of mammals observed on Petrie Islands is given in Appendix D. The relatively small size of the islands, as well as the mix of habitat, would not be expected to support a great diversity of mammals. However, small mammals such as weasels, moles and mice are often difficult to census without some form of small-mammal trapping (using live-traps), therefore a mammal survey would undoubtedly reveal more than the nine species reccrded to date.

E. Reptiles and Amphibians of Petrie islands

Five species of turtles, including one introduced species (Darbyshire 1997), have been recorded, along with three frog species and one species of snake. As with all other surveys noted, a more intensive study should find further additions to this list (Appendix E).


Brunton, Dan. 1998. Distributionally Significant Vascular Flora of the Region of Ottawa – Carleton. Prepared for the Regional Municipality of Ottawa – Carleton, 36p.

Brunton, Dan and Bruce Di Labio.1997. The Flora of Ottawa River Emergent Beaches. Trail & Landscape, 31: 109 – 123.

Cumberland Planning Department. July 1998. Petrie Island Master Plan, Background and Issue Paper, 15p.

Darbyshire, Stephen. 1986. More on the Bladdernut Shrub. Trail & Landscape 21: 26-28.

Darbyshire, Stephen. 1997. A Red-eared Slider in the Ottawa River. Trail & Landscape, 31:157 – 160.

Dugal, Albert. 1977. Petrie Islands Woods Resource Inventory. Prepared on behalf of the Ottawa Field-Naturalists’ Club for submission to the RMOC, 1 1p.

Friends of Petrie Islands. 1998. Petrie Island. Report to Cumberland Council, October 1998. Presented by Al and Helen Tweddle, 4p.

Gillett, John M. and David J. White. 1978. Checklist of Vascular Plants of the Ottawa- Hull Region, Canada. National Museum of Natural Science, Ottawa. 155p.




Acer saccharinum x A. rubrum Silver Maple x Red Maple
Carya cordiformis Bitternut Hickory
Celtis occidentalis Hackberry
Fraxinus nigra Black Ash
Fraxinus pennsylvanica Red Ash
Juglans cinerea Butternut
Populus deltoides Eastern Cottonwood
Populus deltoides x P. grandidentata Eastern Cottonwood x Large-toothed Aspen
Quercus macrocarpa Bur Oak
*Robinia pseudoacacia Black Locust
Salix nigra Black Willow
Tilia americana Basswood
Ulmus americana White Elm
Ulmus rubra ? Slippery Elm


Alnus rugosa (incana) Speckled Alder
Cornus obliqua Silky Dogwood
Cornus rugosa Round-leaved Dogwood
Cornus stolonifera Red-osier Dogwood
Ilex verticillata Winterberry
*Lonicera tatarica Tartarian Honeysuckle
Myrica gale Sweet Gale
Physocarpus opulifolius Ninebark
*Rhamnus cathartica Common Buckthorn
*Rhamnus frangula Glossy Buckthorn
Rhus radicans Poison Ivy
Rhus typhina Staghorn Sumac
Rosa sp. Rose sp.
Rubus allegheniensis Common Blackberry
Rubus odoratus Purple-flowering Raspberry
Salix spp. Willow spp.
Sambucus canadensis Elderberry
Spiraea latifolia Broad-leaved Meadowsweet
Staphylea trifolia Bladdernut Shrub
Toxicodendron radicans Climbing Poison Ivy
Viburnum sp. Viburnum sp.
Viburnum trilobum High-bush Cranberry




Amphicarpaea bracteata Hog Peanut
Apios tuberosa Groundnut
Celastrus scandens Bittersweet
Clematis virginiana Virgin's Bower
*Humulus lupulus Hops
Menispermum canadense Moonseed
Parthenocissus quinquefolia Virginia Creeper
Sicyos angulatus One-seeded Bur Cucumber
Smilax herbacea Carrion Flower
Vitis riparia Riverbank Grape


*Achillea millefolium Yarrow
*Agropyron repens Couch Grass
Agrostis perennans Autumn Bent Grass
Alisma triviale Water Plantain
*Alliaria officinalis Garlic Mustard
Allium canadense Canada Onion
Ambrosia artemisiifolia Common Ragweed
Anemone canadensis Canada Anemone
Apocynum androsaemifolium Spreading Dogbane
Apocynum cannabinum? Indian Hemp?
*Arctium major Burdock
Arisaemum triphyllum Jack-in-the-pulpit
*Artemisia biennis Biennial Wormwood
*Artemisia vulgaris Common Mugwort
Asclepias syriaca Common Milkweed
Asclepias incarnata Swamp Milkweed
Aster lanceolatus Panicled Aster
Aster novae-angliae New England Aster
Aster umbellatus Flat-topped Aster
Astragalus canadensis Milk-vetch
Bidens cernua Bur-marigold
Bidens frondosa Beggarticks
Boehmeria cylindrica False Nettle
*Butomus umbellatus Flowering Rush
Calamagrostis canadensis Canada Blue Joint
*Campanula rapunculoides Creeping Bellflower
Cardamine pensylvanica Pennsylvania Bittercress
Carex bromoides Brome-like Sedge
Carex folliculata Folliculate Sedge
Carex lupulina Hop Sedge
Carex typhina Cattail Sedge
Chelone glabra Turtlehead
Chenopodium glaucum Oak-leaved Goosefoot
*Chrysanthemum leucanthemum Oxeye Daisy
*Cichorium intybus Chicory
Cicuta bulbifera Bulb-bearing Water Hemlock
Circaea quadrisulcata Enchanter's Nightshade
*Cirsium arvense Canada Thistle
*Cirsium vulgare Bull Thistle
*Commelina communis Asiatic Dayflower
Convolvulus sp. Bindweed sp.
*Coronilla varia Crown Vetch
Cyperus acuminatus  
Cyperus diandrus Two-stamened Cyperus
Cyperus odoratus Engelmann's Umbrella-sedge (incl. C. engelmanii)
Cyperus rivularis River Cyperus
Cyperus strigosus Strigos Cyperus
Danthonia spicata Poverty Grass
*Daucus carota Queen Anne's Lace
Desmodium canadense Showy TickTrefoil
*Digitaria ischaemum Small Crab Grass
Dulichium arundinaceum Three-way Sedge
Echinochloa microstachya  
Echinochloa wiegandii  
Eleocharis obtusa Blunt Spike-rush
Elodea canadensis Canada Water-weed
Elymus virginicus Wild Rye
Epilobium angustifolium Fireweed
Epilobium glandulosum Northern Willow Herb
Epilobium strictum Downy Willow Herb
*Epipactis helleborine Helleborine
Eragrostis hypnoides Moss-like Love Grass
*Eragrostis minor  
*Eragrostis pectinacea Pectinate Love Grass
Erechtites hieracifolia Pilewort
Erigeron annuus Daisy Fleabane
Erigeron (Conyza) canadensis Horseweed
*Erysimum (cheiranthoides?) Wormseed Mustard
Eupatorium maculatum Spotted Joe-pye Weed
Eupatorium rugosum White Snakeroot
Fimbristylis autumnalis Autumn Fimbristylis
Fragaria virginiana Wild Strawberry
Galium aparine Cleavers
Galium obtusum Wild Madder
Galium triflorum Sweet-scented Bedstraw
Gerardia tenuifolia Slender Gerardia
Geum sp. Geum sp.
*Glechoma hederacea Ground Ivy
Glyceria borealis Northern Manna Grass
Glyceria striata Fowl Manna Grass
Gnaphalium uliginosum Low Cudweed
*Helianthus tuberosus Jerusalem Artichoke
*Hydrocharis morsus-rani European Frog-bit
Hypericum virginicum Marsh St.Johnswort
*Hypericum perforatum Common St. Johnswort
Impatiens capensis Jewelweed
*Inula helenium Elecampane
Iris versicolor Larger Blue Flag
Junco bufonius Toad Rush
Juncus effusus Common Rush
Juncus filliformis Thread Rush
Juncus pelocarpus Brown-fruited Rush
Juncus tenuis Slender Rush
Lactuca sp Lettuce sp.
Laportea canadensis Wood Nettle
*Lappula myosotis Stickseed
*Lathyrus latifolius Everlasting Pea
Lathyrus palustris Marsh Vetchling
Leersia oryzoides Rice Cut Grass
Leersia virginica Cutgrass
Lemna minor Lesser Duckweed
Lemna trisulca Ivy-leaved Duckweed
*Leonurus cardiaca Motherwort
*Lepidium sp. Peppergrass sp.
*Linaria vulgaris Butter-and-eggs
Lobelia cardinalis Cardinal Flower
Lobelia inflata Indian Tobacco
*Lotus corniculatus Birdsfoot Trefoil
Ludwigia palustris Marsh Purslane
Lycopus americanus Cut-leaved Water-horehound
Lycopus uniflorus Northern Bugleweed
Lysimachia ciliata Fringed Loosestrife
*Lysimachia nummularia Moneywort
Lysimachia terrestris Yellow Loosestrife
*Lythrum salicaria Purple Loosestrife
*Melilotus alba White Sweet Clover
Mentha arvense Wild Mint
Mimulus ringens Monkey Flower
*Mollugo verticillata Carpetweed
Muhlenbergia frondosa Wirestem Muhlenbergia
*Myriophyllum spicatum Spiked Water Milfoil
Najas flexilis Naiad
*Nepeta cataria Catnip
Nuphar variegatum Yellow Pond Lily
Nymphaea odorata  
Nymphaea tuberosa Tuberous Water Lily
Oenothera biennis Common Evening Primrose
Oxalis europaea Yellow Wood Sorrel
Panicum capillare Old Witch Grass
Panicum gattinger Gattinger's Panic Grass
Panicum lanuginosum Hairy Panic Grass
Panicum tuckermanii Tuckerman's Panic Grass
*Phalaris arundinacea Reed Canary Grass
Physalis sp  
Pilea pumila Clearweed
*Plantago major Common Plantain
Poa palustris Swamp Meadow Grass
Poa pratensis Kentucky Blue Grass
Polygonum sp. Polygonum sp.
*Polygonum aviculare Prostrate Knotweed
*Polygonum cuspidatum False Bamboo
*Polygonum persicaria Lady's Thumb
Pontederia cordata Pickerelweed
*Potentilla argentea Silvery Cinquefoil
Potentilla norvegica Rough Cinquefoil
Potamogeton vaseyi Vasey's Pondweed
Potamogeton zosteriformis Flat-stem Pondweed
*Prunella vulgaris Selfheal
Ranunculus abortivus Kidneyleaf Buttercup
Ranunculus pensylvanicus Bristly Crowfoot
Rudbeckia hirta Black-eyed Susan
*Rumex obtusifolius Broad-leaved Dock
Sagittaria graminea Grass-leaved Arrowhead
Sagittaria latifolia Broad-leaved Arrowhead
Saponaria officinalis Soapwort (Bouncing Bet)
Scirpus pedicillatus Pedicled Bulrush
Scirpus pungens  
Scirpus validus Strong Bulrush
Scutellaria galericulata Common Skullcap
*Sedum acre Mossy Stonecrop
*Setaria glauca Foxtail
*Setaria verticillata Bur Bristle Grass
*Setaria viridis Green Foxtail
*Silene cucubalus Bladder Campion
Sisyrinchium angustifolium Blue-eyed Grass
Smilacina racemosa False Solomon's seal
Smilacina stellata Starry False Solomon's seal
*Solanum dulcamara Nightshade
Solidago altissima Tall Goldenrod
Solidago gigantea Late Goldenrod
Solidago (Euthamia) graminifolia Narrow-leaved Goldenrod
Solidago rugosa Rough-stemmed Goldenrod
*Sonchus oleraceus Common Sow-thistle
Sparganium americanum American Bur-reed
Sparganium eurycarpum Broad-fruited Bur-reed
Spartina pectinata Cordgrass
Stachys tenuifolia Common Hedge Nettle
*Taraxacum officinale Dandelion
Thalictrum polygamum Tall Meadowrue
*Tragopogon pratensis Yellow Goat's-beard
*Trifolium dubium Least Hop Clover
*Trifolium hybridum Alsike Clover
Typha latifolia Cattail
Urtica dioica Stinging Nettle
Utricularia vulgaris Common Bladderwort
Vallisneria americana American Eel-grass
*Verbascum thapsus Common Mullein
Verbena hastata Blue Vervain
Verbena urticifolia White Vervain
*Veronica peregrina Purslane Speedwell
Vicia americana American Vetch
Viola sp. Violet sp.
Xanthium strumarium Cocklebur
Zosterella dubia Mud Plantain


Athyrium felix-femina Lady Fern
Botrychium multifidum Leathery Grape Fern
Matteuccia strutheopteris Ostrich Fern
Onoclea sensibilis Sensitive Fern
Osmunda regalis Royal Fern
Equisetum arvense Field Horsetail
Equisetum hyemale Rough Horsetail


Regionally Significant Native Plants Found on Petrie Islands

As determined by Gillett and White 1978 [1], and Brunton 1998 [2]. The Nature Conservancy rarity code (S1, S2,S3 or S3S4) employed by the Natural Heritage Information Centre to designate a provincially rare species, as noted in Brunton 1998, is used where applicable.

Allium canadense(1,2) Canada Onion
Apios tuberosa(1) Groundnut
Astragalus canadensis(1) Canadian Milk-vetch
Carex folliculata(1,2)S3 Folliculate Sedge
Carex typhina(1,2)S2 Cattail Sedge
Celtis occidentalis(1) Hackberry
Cyperus diandrus(2) Two-stamened Cyperus
Cyperus odoratus(2) Engelmann's Umbrella-sedge (incl. C. engelmannii)
Cyperus strigosus(1) Strigos Cyperus
Dulichium arundinaceum(1) Three-way Sedge
Echinochloa microstachya(2)  
Epilobium strictum (1,2) Downy Willow Herb
Eragrostis hypnoides(1,2) Mossy Love Grass
Fimbristylis autumnalis(1,2) Autumn Fimbristylis
Galium aparine(1) Cleavers
Galium obtusum(1,2) Wild Madder
Muhlenbergia frondosa(1,2) Wirestem Muhlenbergia
Panicum gattingeri(2)S3 Gattinger's Panic Grass
Panicum tuckermanii(1,2) Tuckerman's Panic Grass
Potamogeton vaseyi(1,2) Vasey's Pondweed
Potamogeton zosteriformis(1) Flat-stem Pondweed
Scirpus pedicillatus(1,2) Pedicled Bulrush
Sisyrinchium angustifolium(2) Blue-eyed Grass
Sparganium americanum(1,2) American Bur-reed
Staphylea trifolia(1,2) Bladdernut Shrub
Toxicodendron radicans(2) Climbing Poison Ivy
Verbena urticifolia(1,2) White Vervain
Vicia americana(1,2) American Vetch
Zosterella dubia(1) Mud Plantain