A report prepared for the Environmental Management Division,

Planning & Growth Management Department, City of Ottawa








                                             By Daniel F. Brunton



                                                     March 2005



Acknowledgements............................................................................................................................ ii


1.0   INTRODUCTION................................................................................................................... 1

1.1 Status of native taxa......................................................................................................... 1

1.2 Non-native (introduced) taxa .......................................................................................... 3

1.3 New Data....................................................................................................................... 4

1.4 Annotated list.................................................................................................................. 5


2.0   LITERATURE AND DOCUMENT REFERENCES.............................................................. 87






ATTACHMENT 1 - INDEX to Vascular Plant Genera .................................................................. 91


ATTACHMENT 2: Excluded taxa................................................................................................. 106


ATTACHMENT 3: Alphabetical listing of Regionally Significant taxa.............................................. 110


ATTACHMENT 4: Regionally Significant taxa locations................................................................. 126






Unpublished specimen data from a number of field botanists, most particularly Paul M. Catling, William J. Crins William Draper, Albert Dugal, the late Clarence Frankton, Catherine J. Keddy, Michael J. Oldham, Joyce M. Reddoch and David J. White, were incorporated into this list over a period of several years. Application of these unpublished data have supplemented in-house knowledge of the vascular plants of Ottawa gained both from extensive field experience and from off-site floristic research. The contributions from other field botanists have significantly enhanced the usefulness of the final list.


Many additional records were gleaned from examination of the herbarium specimens, as noted in the Introduction (above). Those preserved at Agriculture Canada (DAO) and the Canadian Museum of Nature (CAN) constitute particularly large and important information sources. Collection managers Gizèle Mitrow and Michael Shchepanek (respectively), greatly facilitated these herbarium investigations.


A number of taxonomic specialists were consulted for identifications and/ or nomenclatural insight for some of the plant groups addressed. These include Donald M. Britton, University of Guelph (pteridophytes), George W. Argus, Canadian Museum of Nature (Salicaceae), William J. Crins, Ontario Ministry of Natural Resources (Cyperaceae; Juncaceae; Poaceae), Stephen Darbyshire, Agriculture Canada (Poaceae), Paul M. Catling, Agriculture Canada (Cyperaceae, Orchidacae, Juncaceae), John Semple, University of Waterloo (Asteraceae), Gerald Mulligan, Agriculture Canada (Brassicaceae), Erich Haber, Canadian Museum of Nature (Pyrolaceae), James Phipps, University of Waterloo (Rosaceae) and Tony Reznicek, University of Michigan (Cyperaceae).


The annotated list was enhanced significantly by the reviews of botanists Michael Oldham, David White, Paul Catling and Albert Dugal. These gentlemen provided numerous valuable comments, corrections, additions and observations. Any errors or emissions which may have escaped their sharp eyes, however, remain the author’s responsibility.


This document also benefited from the efforts of Bernie Muncaster, Muncaster Environmental, in the development of the generic index, and through the work of Susan Murphy, City of Ottawa, in final production.




Accurate identification of the diversity and abundance of species occurring in a particular site provides a valuable indication of the ecological significance of that area’s natural habitats. It also provides important information on possible mitigation, restoration and/ or conservation opportunities. Trends in both population size and the total diversity of significant native species also provide valuable tools in monitoring the overall ecological health of landscapes. Significant species abundance and occurrence information extracted from an earlier floristic data base (Brunton 1998), for example, has been applied to various environmental management purposes in the City of Ottawa, including sensitive areas determinations, the relative rating of different natural areas, and for ecological integrity monitoring. None of these applications can be confidently undertaken, however, without an accurate and comprehensive listing of floristic diversity.


A total of 1,569 species, subspecies and hybrid vascular plant taxa are known to occur (or to have occurred) within the City of Ottawa (former Region of Ottawa-Carleton). Nomenclature in the following list generally follows the most recent taxonomic treatments (e.g. Flora of North America series), with synonyms frequently employed in the Ottawa area noted in brackets. The annotated list  is compiled from a variety of sources, including:


·        review of verifiable regional literature (see References);

·        examination of preserved specimens in the major contemporary depositories of City of Ottawa floristic information, including the Canadian Museum of Nature (CAN), Agriculture Canada (DAO), the Royal Ontario Museum (TRT) and the private herbarium of Daniel F. Brunton (Dfb);

·        input from experienced and expert field botanists (see Acknowledgments).



1.1 Status of native taxa


The native vascular flora of the City of Ottawa (former Region of Ottawa-Carleton), including a small number of taxa with both native and non-native populations, includes 1,014 vascular plant species, subspecies and hybrids. Native species designated as ‘Common’  occur frequently within the City of Ottawa, often in large numbers, throughout their appropriate, typically widespread habitat(s). ‘Uncommon’ taxa are found only occasionally within suitable habitat, often in small numbers. The habitat of ‘Uncommon’ species is often geographically limited as well. ‘Rare’ taxa in Ottawa (their names highlighted in bold type) represent native species, subspecies and varieties which further designated as follows:



(PS)  Provincial Conservation Concern - typically known from fewer than 100 populations known in Ontario; the NatureServe subnational conservancy status rank (SRANK) assigned to each species by the Ontario Heritage Information Centre (Oldham 1999) is noted, followed by the statement of their status in Ottawa. NatureServe codes employed here are:


o       S1 - Extremely rare in Ontario; usually 5 or fewer occurrences;

o       S2 - Very rare in Ontario; usually between 6 and 20 occurrences or with many individuals in fewer occurrences;

o       S3 - Rare in Ontario; usually between 21 and 100 occurrences;

o       S4 - Uncommon to locally common in Ontario and apparently secure; usually between 101 and 1000 occurrences.


The provincial status of such taxa are updated, when and as data become available. Such changes can be reviewed at any time on the Ontario Heritage Information Centre web page:


(RS) - Regionally Significant - known from 10 or fewer contemporary populations (post-1969) in the City of Ottawa. This includes the Rare (5 or fewer populations) and Sparse (6 to 10 populations) categories employed by Gillett & White (1978) and Brunton (1998). Species known only from pre-1970 records are annotated as Rare (Historic). The year 1970 was selected as a reasonable limit of our understanding of ‘contemporary’ since it constitutes a sufficiently long period of time (35 years)  for the development of a comprehensive set of data while still offering the likelihood of substantially unchanged site conditions at particular locations.


Some listings for native vascular plant species are annotated in the ‘Sites/ Status’ column to provide additional information on their status within the City of Ottawa. Those qualifiers include:


o       [site name]* - an asterisk following a particular site name indicates that two to four separate populations of this significant species are known from this particular site. If the number of populations (geographically separated occurrences) within a particular location is known to be greater than four, that is explicitly stated.


o       Uncommon [number] - a bracketed numeral in the status column indicates the number of sites (under 20) for species which were previously considered to be Regionally Rare in Gillett & White (1978) and/ or Brunton (1998) but for which between 11 and 20 contemporary populations are known. These are considered to have a measure of special features significance at a Regional (City of Ottawa) level but not to the level of Regionally Rare taxa. The names of such species are cited in bold type to further distinguish them more widespread uncommon taxa.


Native hybrids involving at least one rare parent are also considered Regionally Significant. Hybrids between common or uncommon taxa, and adventive species (taxa native elsewhere in North America but occurring here as a result of human activity), are not so listed however.


Status statements reflect the known distribution of each taxon as supported by specimens in significant City of Ottawa voucher collections. Credibly documented citations in botanical literature and reports (as listed) are also considered. Populations known from somewhat older records (1950-1969) from sites likely to have retained those particular species (e.g. the middle of large area known to have maintained its natural character) are also included as ‘contemporary. The status statement for species with both native and introduced populations applies to the native portion of the population, unless otherwise stated.



1.2 Non-native (introduced) taxa


A substantial proportion (36%) of the flora of the City of Ottawa is not native to this area. These 571 taxa are indicated by the symbol ‘#’ in the column following their scientific name. Taxa so indicated include species and hybrids not native to North America (introductions), as well as adventives - taxa native elsewhere in North America but established in the City of Ottawa as a result of ±recent (historic period) human activity.


Species marked with the introduced symbol within square brackets ‘[#]’ have both native and non-native populations in Ottawa. As noted above, status statements for species with both native and introduced populations apply to the native populations.


Status designations for non-native plants species are less precise than they are for native taxa since the interpretation of such information is typically less useful. This reflects the frequently arbitrary distribution of such human-assisted plants and their limited or even negative natural environment values. In that regard, it can be especially difficult to determine if ‘wild’ occurrences of cultivated plants represent individuals persisting after planting or established, reproducing populations. We have erred on the side in including such ambiguous taxa on the list.


Non-native taxa designated as ‘Common’ are present in large numbers in at least a substantial portion of the City of Ottawa (e.g. several geographic townships). ‘Uncommon’ non-native taxa are seen infrequently in the City, typically occurring in small numbers but over a relatively large area of the municipality. ‘Rare’ non-native species are known from a small number of contemporary records, typically five or fewer populations being known.


1.3 New Data


A data base such as this is dynamic and reflects the state of knowledge of a complex subject at a particular time. In this case, the cut-off date is 15 April 2005. While it is important and  worthwhile to periodically present such data in a single package, new information continues to accumulate. Documentation of supplementary data, therefore, is important for the maintenance of a complete and applicable data base. Users of floristic data in Ottawa, be they amateur naturalists or professional field botanists, can make important contributions by documenting such observations and findings.


The most useful method for documenting new records is through preservation of a suitably prepared voucher specimen in a public herbarium, such as one of the collections cited in this document. Observations of species of Conservation Concern can also be documented by filing a Species Report on the Ontario Natural Heritage Centre web page at The record becomes part of the province-wide data base directing many conservation and management efforts across Ontario. Reports of additional records of significant Ottawa vascular plant taxa would also be welcomed by the author (


1.4 Annotated list


Scientific Name


Common Name

Status/ Sites

LYCOPODIACEAE  (Clubmoss Family)

Diphasiastrum complanatum (L.) Holub

(Lycopodium complanatum L.)


Northern Ground-cedar

RS (7): Marshall Bay; Stony Swamp CA; The Burnt Lands; Greely East; Magladry Road South Vars East; Ont. Land Corp.

Diphasiastrum digitatum (A. Br.) Holub

(Lycopodium digitatum A. Br.; L. flabelliforme (Fern.) Blanch.)




Diphasiastrum ×habereri (House) Holub

(D. digitatum (A. Br.) Holub x tristachyum (Pursh) Holub)


hybrid Ground-cedar

RS (3): Stony Swamp CA; Marshall Bay; South March Highlands.

Diphasiastrum tristachyum (Pursh) Holub

(Lycopodium tristachyum Pursh)



RS (7*): Mer Bleue CA; Constance Bay (Sand Hills); Stony Swamp CA (2+ populations), South March Highlands; Vars West; Marlborough Forest (Paden Road alvar); Marathon West

Diphasiastrum ×zeilleri (Rouy) Holub

(D. complanatum (L.) Holub x tristachyum (Pursh) Holub)


hybrid Ground-cedar

RS (3): Marshall Bay; Fitzroy Harbour; Limestone Road

Huperzia lucidula (Michx.) Trev.

(Lycopodium lucidulum Michx.)


Shining Clubmoss

Common (local)

Huperzia selago (L.) Bernh.

(Lycopodium selago L.)


Mountain Clubmoss

Provincial Conservation Concern (S3S4); RS (1*): Stony Swamp CA*

Lycopodiella inundata (L.) Holub

(Lycopodium inundatum L.)


Bog Clubmoss

RS (8*): Mer Bleue CA*; Stony Swamp CA;   Magladry Road South; Vars East; Vars West; Herberts Corner Bog; Ont. Land Corp; Anderson Road.

Lycopodium annotinum L.


Running Clubmoss


Lycopodium clavatum L.


Staghorn Clubmoss


Lycopodium dendroideum Michx.


Common Ground-pine


Lycopodium hickeyi Wagner, Beitel & Moran

(L. obscurum L. var. isophyllum Hickey)


Hickey's Ground-pine 


Lycopodium lagopus (Laest.) Zin. ex Kuz.

(L. clavatum L. var. monostachyon Grev. & Hook.)


One-cone Clubmoss

RS (2): Mer Bleue CA.; Osgoode Swamp (Springhill Bog).

Lycopodium obscurum L.



Uncommon [16]

EQUISETACEAE  (Horsetail Family)

Equisetum arvense L.


Field Horsetail


Equisetum fluviatile L.


Water Horsetail


Equisetum hyemale L.


Scouring Rush


Equisetum ×litorale Kuhl.

(E. arvense L. x fluviatile L.)


Shoreline Horsetail


Equisetum ×mackaii (Newm.) Brichan

(E. x trachydon A. Br.; E. hyemale L. x variegatum Schleich.)


hybrid Horsetail


Equisetum palustre L.


Marsh Horsetail

RS (5): Crystal Bay (Beatty Point); Stony Swamp CA; Mer Bleue CA; Magladry Road South; Duck Islands.

Equisetum pratense Ehrh. 


Meadow Horsetail

Uncommon [14]

Equisetum scirpoides Michx.


Dwarf Scouring-rush


Equisetum sylvaticum L.


Woodland Horsetail


Equisetum variegatum Schleich.


Variegated Scouring-rush


SELAGINELLACEAE  (Spikemoss Family)

Selaginella eclipes Buck

(S. apoda (L.) Fern., p. pt.)


Meadow Spikemoss

RS (6): Shirleys Bay (Innis Point); Morris Island (Lavergne Bay); Marshall Bay; Wattersons Corners; Fitzroy Harbour;  Marlborough Forest.

Selaginella rupestris (L.) Spring


Rock Spikemoss

RS (6*): Carp Hills *(Carp Barrens; Carp); Constance Bay (sand Hills); The Burnt Lands; Morris Island (Mississippi Snye); South March Highlands; Panmure Alvar.

ISOETACEAE  (Quillwort Family)

Isoetes ×dodgei Eat.

(I. echinospora Dur. x riparia Engelm.)


Dodge's Quillwort

RS (7): Woodridge; Crown Point; Buchans Bay; Fitzroy Provincial Park*; Horseshoe Bay; Britannia CA; Deschenes Lookout ESA

Isoetes echinospora Dur. ssp. muricata (Dur.) Löve & Löve


Spiny-spored Quillwort


Isoetes ×hickeyii Taylor & Luebke

(I. echinospora Dur. x macrospora Dur.)


Hickey's Quillwort

RS (1): Deschenes Lookout ESA

Isoetes macrospora Dur.

(I. lacustris, p. pt.)


Large-spored Quillwort

RS (2): Constance Bay shores; Deschenes Lookout ESA.

Isoetes riparia Engelm.


River Quillwort

Provincial Conservation Concern (S3); RS (10): Woodridge; McLarens Landing; Crown Point; Morris Island (Morris Island CA; Chats Dam); Fitzroy Provincial Park*; Buchans Bay; Horseshoe Bay; Britannia CA*; Deschenes Lookout ESA; Champlain Bridge; Lemieux Islands.

OPHIOGLOSSACEAE  (Grapefern Family)

Botrychium dissectum Spreng.

(incl. forma obliquum (Muhl.) Fern.)


Cut-leaved Grapefern


Botrychium lanceolatum (Gmel.) Angstr.


Daisy-leaved Moonwort

Provincial Conservation Concern (S3); RS (5): Stony Swamp CA; South March Highlands; Baxter CA; Pinhey Forest; Britannia CA.

Botrychium matricariifolium A. Br.


Matricary Grapefern


Botrychium minganense Victorin


Mingan Moonwort

RS (1*): Stony Swamp CA*

Botrychium multifidum (Gmel.) Rupr.

(incl. var. intermedium (Eat.) Farw.)


Leathery Grapefern


Botrychium oneidense (Gilb.) House


Blunt-lobed Grapefern

Provincial Conservation Concern (S3); RS (2): Woodlawn; Bell High School Woods.

Botrychium rugulosum W.H. Wagner

(B. ternatum, auct.)


St. Lawrence Grapefern

Provincial Conservation Concern (S2); RS (3): Pinhey Forest; Stony Swamp CA; Magladry Road South.

Botrychium simplex E. Hitchc.


Least Moonwort


Botrychium virginianum (L.) Sw.


Rattlesnake Fern


Ophioglossum pusillum Raf.

(O. vulgatum L. var. pseudopodium (Blake) Farw.)


Adder's-tongue Fern

RS (5*): Stony Swamp CA (several populations); Manions Corners; Leitrim (several populations); Shirleys Bay (Innis Point); South Gloucester.

OSMUNDACEAE  (Flowering-fern Family)

Osmunda cinnamomea L.


Cinnamon Fern


Osmunda claytoniana L.


Interrupted Fern


Osmunda regalis L. var. spectabilis (Willd.) Gray


Royal Fern


PTERIDACEAE  (Maidenhair Fern Family)

Adiantum pedatum L.


Maidenhair Fern


Cryptogramma stelleri (Gmel.) Prantl.


Slender Cliffbrake

RS (3): Rockcliffe Park ESA; Riverside Park; Fitzroy Prov. Park.


DENNSTAEDTIACEAE  (Bracken Fern Family)

Dennstaedtia punctilobula (Michx.) Moore


Hay-scented Fern


Pteridium aquilinum (L.) Kuhn var. latiusculum (Desv.) Underw.





Phegopteris connectilis (Michx.) Watt


Northern Beech Fern

Common (local)

Thelypteris noveboracensis (L.) Nieuwl.


New York Fern


Thelypteris palustris (Salisb.) Schott


Marsh Fern


BLECHNACEAE  (Chain Fern Family)

Woodwardia virginica (L.) Sm.


Virginia Chain Fern

RS  (2*): Mer Bleue CA (common); Herberts Corners Bog.

ASPLENIACEAE  (Spleenwort Fern Family)

Asplenium platyneuron (L.) Oakes


Ebony Spleenwort

RS (2*): Stony Swamp CA (6* populations); South Gloucester.

Asplenium rhizophyllum L.

(Camptosorus rhizophyllus (L.) Link)


Walking Fern

RS (9): Barrhaven; Mud Pond; Buchans Bay West; Marlborugh Forest (Cedar Grove Trail); Corkery; Constance Creek; Dunrobin; South Gloucester; Stony Swamp CA.

Asplenium trichomanes L. ssp. quadrivalens Meyer


Tetraploid Maidenhair Spleenwort

RS (3): Barrhaven; Stony Swamp CA; Rockcliffe Park ESA.

Asplenium trichomanes L. ssp. trichomanes


Diploid Maidenhair Spleenwort

RS (2): South March Highlands; Carp Hills.


Athyrium filix-femina (L.) Roth var. angustum (Willd.) Lawson


Lady Fern


Cystopteris bulbifera (L.) Bernh.


Bulblet Bladder-fern


Cystopteris fragilis (L.) Bernh.


Fragile Fern


Cystopteris tenuis (Michx.) Desv.

(C. fragilis (L.) Bernh. var. mackayii Lawson)


Mackay's Brittle Fern


Deparia acrostichoides (Sw.) Kato

(Athyrium thelypterioides (Michx.) Desv.)


Silvery Spleenwort


Diplazium pycnocarpon (Spreng.) Broun

(Athyrium pycnocarpum (Spreng.) Tidestr.)


Glade Fern

RS (8*): South March Highlands; Antrim Black Maple ANSI; Antrim Woodlot; North Gower*; Manotick ANSI; Vars East; South Gloucester; Cardinal Creek.

Dryopteris ×benedictii Wherry

(D. carthusiana (Vill.) Fuchs x clintoniana (Eat.) Dow.)


Benedict's Woodfern


Dryopteris ×boottii (Tuckerm.) Underw.

(D. cristata (L.) A. Gray x intermedia (Muhl.) A. Gray)


Boott's Woodfern


Dryopteris carthusiana (Vill.) Fuchs

(D. spinulosa (Muell.) Watt)


Spinulose Woodfern


Dryopteris clintoniana (Eat.) Dow.


Clinton's Woodfern


Dryopteris clintoniana (Eat.) Dow. x cristata (L.) A. Gray


hybrid Woodfern


Dryopteris cristata (L.) A. Gray


Crested Woodfern


Dryopteris ×dowellii Wherry

(D. clintoniana (Eat.) Dow. x intermedia (Muhl.) A. Gray)


Dowell's Woodfern


Dryopteris goldiana (Hook.) A. Gray


Goldie's Woodfern

RS (7): Beechwood cemetery; Antrim Black Maple ANSI; Antrim; South March Highlands; Marlborough Forest; Little's Woods; South Gloucester.

Dryopteris intermedia (Muhl.) A. Gray


Evergreen Woodfern


Dryopteris marginalis (L.) A. Gray


Marginal Shieldfern


Dryopteris ×mickelii J. Peck

(D. clintoniana (Eat.) Dow. x goldiana (Hook.) A. Gray)


hybrid Woodfern

RS (3): Beechwood; Cody Creek Black Maple ANSI; South March Highlands.

Dryopteris ×triploidea Wherry

(D. carthusiana (Vill.) Fuchs x intermedia (Muhl.) A. Gray)


Triploid Woodfern


Dryopteris ×uliginosum (A. Br.) Druce

(D. carthusiana (Vill.) Fuchs x cristata (L.) A. Gray)


hybrid Woodfern


Gymnocarpium dryopteris (L.) Newm.


Oak Fern


Gymnocarpium robertianum (Hoffm.) Newm.   


Limestone Oak Fern

Provincial Conservation Concern (S2); RS (Historic): old record (Albion Wetland)

Matteuccia struthiopteris (L.) Todaro


Ostrich Fern


Onoclea sensibilis L.


Sensitive Fern


Polystichum acrostichoides (Michx.) Schott


Christmas Fern

Uncommon [19*]

Woodsia oregana D.C. Eat. ssp. cathcartiana (Robins.) Wind.


Cathcart's Woodsia

Provincial Conservation Concern (S3); Extirpated: South March Highlands.

Woodsia ilvensis (L.)  R. Br.


Rusty Woodsia

RS (2*): Stony Swamp CA*; South March Highlands*.

AZOLLACEAE (Mosquito Fern Family)

Azolla caroliniana Willd.


Mosquito Fern

Provincial Conservation Concern (S3); Extirpated (?): large populations along Rideau River & Rideau Canal below Mooneys Bay, 1998 & 2003.

POLYPODIACEAE  (Polypody Fern Family)

Polypodium appalachianum Haufler & Windham

(P. virginianum L. forma acuminatum Fern.)


Appalachian Polypody

Provincial Conservation Concern (S1); RS (1): Rothwell Heights.

Polypodium virginianum L.


Common Polypody


TAXACEAE  (Yew Family)

Taxus canadensis Marsh.


Canada Yew


PINACEAE  (Pine Family)

Abies balsamea (L.) Mill.


Balsam Fir


Larix laricina (Du Roi) K. Koch




Picea glauca (Moench) Voss


White Spruce


Picea mariana (Mill.) BSP.


Black Spruce

Uncommon (locally abundant)  [11]

Pinus banksiana Lamb.


Jack Pine

RS (3*): Constance Bay Sand Hills (locally abundant); Baskins Beach*; Carp Hills [also several large plantations].

Pinus resinosa Ait. 


Red Pine

Uncommon (frequently planted) [15]

Pinus strobus L.


White Pine


Pinus sylvestris L.


Scot's Pine

Rare [frequently planted]

Tsuga canadensis L.


Eastern Hemlock


CUPRESSACEAE (Cypress Family)

Juniperus communis L.


Common Juniper


Juniperus virginiana L.


Red Juniper


Thuja occidentalis L.


White Cedar


TYPHACEAE (Cat-tail Family)

Typha angustifolia L.


Narrow-leaved Cat-tail


Typha ×glauca Godron

(T. angustifolia L. x latifolia L.)


hybrid Cat-tail


Typha latifolia L.


Common Cat-tail


SPARGANIACEAE (Bur-reed Family)

Sparganium americanum Nutt.


American Bur-reed

RS (5): Britannia CA; Stony Swamp CA; Mer Bleue CA; Highway 7 west of Stittsville; Petrie Islands.

Sparganium androcladum (Engelm.) Morong


Branching Bur-reed

Provincial Conservation Concern (S3); RS (1) Historic: Old record, Billings Bridge.

Sparganium emersum Rehm.

(S. chlorocarpum Rydb.)


Green Bur-reed


Sparganium eurycarpum Engelm.


Broad-fruited Bur-reed


Sparganium fluctuans (Morong) Robins.


Floating Bur-reed

RS (5): Upper Duck Island; Lower Duck Island; Greens Creek CA; South March Highlands; Crown Point.

Sparganium natans L.

(S. minimum (Hartm.) Fries)


Small Bur-reed

RS (9*): Huntley Wetland; Poole Creek Wetland *(Rothbourne Swamp, south of Dibblie Quarry); Mer Bleue CA; Stony Swamp CA; Morris Island; Marlborough Forest; Dwyer Hill; Jinkinson Road.



Potamogeton amplifolius Tuckerm.


Large-leaf Pondweed

RS (5): Constance Creek; Huntley Creek; Marlborough Forest (Brassils Ck); Baskins Beach; Deschenes Lookout.

Potamogeton crispus L.


Crisped Pondweed

Uncommon (locally abundant)

Potamogeton epihydrus Raf.


Ribbonleaf Pondweed


Potamogeton foliosus Raf.


Leafy Pondweed


Potamogeton friesii Rupr.


Fries’ Pondweed

RS (1): Britannia CA.

Potamogeton gramineus L.


Grassleaf Pondweed


Potamogeton illinoensis Morong


Illinois Pondweed

RS (3): Duck Islands; South March Highlands; Fitzroy Provincial Park.

Potamogeton natans L.


Floating Pondweed


Potamogeton nodosus Poir.


Longleaf Pondweed


Potamogeton obtusifolius Mert. & Koch


Blunt-leaf Pondweed

RS (1): Poole Creek Wetland (Rothbourne Swamp).

Potamogeton perfoliatus L.


Perfoliate Pondweed

Uncommon (locally abundant in Ottawa River)

Potamogeton praelongus Wulf.


White-stemmed Pondweed

RS (1): Constance Lake

Potamogeton pusillus L.


Small Pondweed


Potamogeton richardsonii (A. Benn.) Rydb.


Richardson's Pondweed


Potamogeton robbinsii Oake


Robbin's Pondweed

Uncommon (locally abundant in Ottawa River)

Potamogeton spirillus Tuckerm.


Northern Snailseed Pondweed


Potamogeton vaseyi Robbins


Vasey's Pondweed

RS (5*): Britannia CA; Morris Island*; Deschenes Lookout ESA; Cumberland*; Petrie Islands.

Potamogeton zosteriformis Fern.


Zig-zag Pondweed


Stuckernia pectinata (L.) Borner

(Potamogeton pectinatus L.)


Sago Pondweed


ZANNICHELLIACEAE (Horned Pondweed Family)

Zannichellia palustris L.


Horned Pondweed

RS (3): Andrew Haydon Park; Britannia Bay; Hope Cloutier Park.

NAJADACEAE (Naiad Family)

Najas flexilis (Willd.) R.& S.





Scheuchzeria palustris L.


Bog Nut-grass

RS (2*): Mer Bleue CA; Marlborough Forest (Richmond Fen; Phragmites Fen).

JUNCAGINACEAE (Arrow-grass Family)

Triglochin maritimum L.



RS (4*): Richmond Fen; Phragmites Fen; Long Swamp; Carlsbad Springs East;  (adventive at Stittsville; Carp).

Triglochin palustre L.



RS (1): Albion Wetland.

ALISMATACEAE (Water-plantain Family)

Alisma gramineum Gmel.


Grass-leaved Water-plantain

Provincial Conservation Concern (S3S4); RS (2): Andrew Haydon Park; Britannia Bay [also adventive].

Alisma triviale Pursh




Sagittaria cuneata Sheld.



RS (6): Champlain Bridge; Britannia Bay.; Marlborough Forest (Brassils Creek); Constance Lake; Horseshoe Bay; Kars (Rideau River).

Sagittaria graminea Michx.


Grass-leaved Arrowhead

Uncommon (locally abundant).

Sagittaria latifolia Willd.


Broad-leaved Arrowhead


Sagittaria rigida Pursh


Stiff-leaved Arrowhead


BUTOMACEAE (Flowering Rush Family)

Butomus umbellatus L. 




HYDROCHARITACEAE (Frog's-bit Family)

Elodea canadensis Michx.


Canada Waterweed


Elodea nuttallii (Planch.) St. John


Nuttall's Waterweed

RS (4): Deschenes Lookout; Fitzroy Harbour; Horseshoe Bay; Shirleys Bay.

Hydrocharis morsus-ranae L. 




Vallisneria americana Michx.






POACEAE (Grass Family)

Agropyron cristatum (L.) Gaertner ssp. pectinatum Tzvelev 


Crested Wheat Grass


Agrostis capillaris L.

(A. tenuis Sibth.)


Brown-top Bent-grass


Agrostis gigantea Roth

(A. alba auct., non L.)




Agrostis perennans (Walt.) Tuckerm


Autumn Bent-grass

Uncommon (rivershores)

Agrostis scabra Willd.


Tickle Grass


Agrostis stolonifera L.

(A. alba L.; A. palustris Huds.)


Creeping Bent Grass


Alopecurus aequalis Sobol.


Water Foxtail Grass


Alopecurus geniculatus L.


Bent Foxtail Grass


Alopecurus pratensis L.


Meadow Foxtail Grass


Andropogon gerardii Vittm.


Big Bluestem

RS (6*): Morris Island*; Shirleys Bay (several populations); Crystal Bay; Baskins Beach; Constance Bay shores; Fitzroy Provinical Park*;  Champlain Bridge (plus adventives).

Anthoxanthum nitens (Weber) Schouten & Veldkamp 

 (Hierochloe odorata (L.) Beauv.)


Sweet Grass

RS (3): Shirleys Bay (Innis Point) ; Vars West; Vars East (uncommonly adventive along roads)

Anthoxanthum odoratum L.


Vernal Grass


Arrhenatherum elatius (L.) Beauv. ex Presl


Tall Oat-grass


Avena fatua L. 


Wild Oats


Avena sativa L. 




Beckmannia syzigachne (Steudel) Fern. 


Slough Grass


Brachyelytrum aristosum (Michx.) Trel.

(Brachyelytrum erectum (Schreb.) P. Beauv. var. glabratum (Vasey ex. Millsp.) Koyama & Kowano)


Bearded Shorthusk

Uncommon [16]

Brachyelytrum erectum (Schreb.) P. Beauv.


Southern Bearded Shorthusk

RS (1): Morgan’s Grant Park

Briza media L. 


Quaking Grass


Bromus ciliatus L.


Fringed Brome Grass


Bromus hordeaceus L. 

(B. mollis L.)


Soft Chess


Bromus inermis Leyss. 


Common Brome Grass


Bromus japonicus Thunb. ex Murr. 


Japanese Chess


Bromus kalmii A. Gray


Kalm's Brome Grass

Uncommon  [14]

Bromus latiglumis (Shear) A. Hitchc.

(B. altissimus Pursh; B. purgans, auct.; B. pubescens, auct., non Muhl. ex Willd)


Canada Brome Grass

RS (2): Edwards; Rideau River (Alta Vista).

Bromus racemosus L. 


Chess Grass


Bromus secalinus L. 


Chear Chess


Bromus tectorum L. 


Downy Chess

Rare (locally common)

Calamagrostis canadensis (Michx.) Beauv.


Canada Bluejoint


Calamagrostis epigejos (L.) Roth 




Calamagrostis stricta (Timm) Koeler ssp. inexpansa (A. Gray) Greene   


Northern Reed Grass

Rare [native elsewhere in Ontario]

Cinna arundinacea L.


Stout Woodreed

Uncommon [13]

Cinna latifolia (Trev. ex Goepp.) Griseb.


Drooping Woodreed

Uncommon [18]

Cynosurus cristatus L. 


Crested Dog's-tail


Dactylis glomerata L. 


Orchard Grass


Danthonia spicata (L.) Beauv. ex R. & S.


Poverty Grass


Deschampsia cespitosa (L.) Beauv.


Tufted Hair Grass

RS (3*): Shirleys Bay (Innis Point; Watts Creek); Marathon Forest; Panmure Alvar.

Deschampsia flexuosa (L.) Trin. 


Wavy Hair Grass

RS (2*): Constance Bay Sand Hills (common); Stony Swamp CA.

Dichanthelium acuminatum (Sw.) Gould & Clarke ssp. columbianum (Scribn.) Freckmann & LeLong

(P. sabulorum Nash. p. pt.; P. tsugetorum Nash; P. ovale, auct.)


Northern Panic Grass

RS (3): Constance Bay Sand Hills; Ontario Land Corp.; Shirleys Bay (Innis Point).

Dichanthelium acuminatum (Sw.) Gould & Clarke ssp. fasciculatum (Torr.) Freckmann & LeLong

(Panicum lanuginosum Ell. var. fasciculatum Fern.; P. acuminatum auct., non Sw.)


Panic Grass


Dichanthelium acuminatum (Sw.) Gould & Clarke ssp. implicatum (Scrib.) Freckmann & LeLong

(Panicum implicatum Scribn.)


Small Panic Grass


Dichanthelium acuminatum (Sw.) Gould & Clarke ssp. lindheimeri (Nash) Freckmann & LeLong

(Panicum lindheimeri Nash; [P. lanuginosum Ell. var. septentrionalis (Fern.) Fern. ? ])


Smooth Panic Grass

RS (4): Morris Island (Lavergne Bay); Fitzroy Provincial Park; Champlain Bridge; Shirleys Bay .

Dichanthelium boreale (Nash) Freckmann

(Panicum boreale Nash) 


Northern Panic Grass

RS (6*): Constance Bay Sand Hills* (common); Fitzroy Provincial Park; Carp Hills (Carp Barrens); Duck Islands; Carlsbad Springs SW.

Dichanthelium depauperatum (Muhl.) Gould

(Panicum depauperatum Muhl.)


Impoverished Panic Grass

RS (6*): Constance Bay Sand Hills* (common); Shirleys Bay (Innis Point); Bruce Pit Woods; Vars West; Pine Grove Forest; Findlay Creek Wetland.

Dichanthelium latifolium (L.) Harvill

(Panicum latifolium L.)


Broad-leaved Panic Grass

RS (1): Fitzroy Provincial Park.

Dichanthelium linearifolium (Scribn.) Gould

(Panicum linearifolium Scribn.)


Narrow-leaved Panic Grass

Common (local)

Dichanthelium xanthophysum (A. Gray) Freckmann

(P. xanthophysum A. Gray)


Yellow Panic Grass

RS (5*): Constance Bay Sand Hills* (common); The Burnt Lands*; Britannia; French Hill Swamp; Vars East.

Digitaria ischaemum (Schreb.) Muhl. 


Small Crab Grass


Digitaria sanguinalis (L.) Scop. 


Large Crab Grass

Common (especially in gardens)

Echinochloa crusgalli (L.) Beauv. 


Barnyard Grass


Echinochloa muricata (Michx.) Fern.

(E. microstchya (Wieg.) Rydb.; E. pungens (Poir.) Rydb, p. pt.; E. wiegandii (Fass.) McNeill & Dore)


Barnyard Grass


Echinochloa walteri (Pursh) Heller


Walter's Barnyard Grass

Provincial Conservation Concern (S3); RS (1): Constance Creek [adventive?].

Elymus canadensis L.


Canada Rye Grass

RS (2*): Morris Island (Chats Dam); Constance Bay*   [plus adventives]

Elymus hystrix L.

(Hystrix patula Moench)


Bottlebrush Grass


Elymus ×maltei Bowden

(E. canadensis L. x virginicus L.)


hybrid Rye Grass

RS (Historic): old record , ‘Ottawa’

Elymus repens (L.) Gould  

(Agropyron repens (L.) Beauv.)


Quack Grass


Elymus trachycaulus (Link)  Gould (s.l.)


Wheat Grass

RS (10*): Constance Bay Sand Hills; Mer Bleue CA; Lemieiux Islands; The Burnt Lands (several); Morris Island*; Panmure Alvar; Carp Hills* (Carp; Carp Barrens); Marathon Forest; Mud Pond; South Gloucester.

Elymus villosus Muhl. ex Willd.


Hairy Rye Grass

RS (1): Stillwater Creek.

Elymus virginicus L.


Wild Rye Grass


Elymus wiegandii Fern.

(Elymus canadensis L. var. wiegandii (Fern.) Bowden)


Wiegand's Wild Rye

RS (Historic): old records, Billings Bridge,Vincent Massey Park; Bear Brook.

Eragrostis cilianensis (All.) Lutati ex Hubb. 

(E. megastachya (Koeler) Link)


Stinking Love Grass


Eragrostis frankii C. Meyer


Frank's Love Grass

RS (8*): Stittsville*; Long Swamp; The Burnt Lands*; Fallowfield; Carp Airport; Manotick; Rideau River Provincial Park; Vars East.

Eragrostis hypnoides (Lam.) BSP.


Mossy Love Grass

RS (1): Petrie Islands.

Eragrostis minor Host 

(E. pooides R. & S.)


Love Grass


 Eragrostis pectinacea (Michx.) Nees var. miserrima (Fourn.) Reeder 

(E. tephrosanthos Schultes)


Love Grass


Eragrostis pectinacea (Michx.) Nees var. pectinacea


Pectinate Love Grass


Eragrostis pilosa (L.) Beauv.


India Love Grass

Rare [formerly considered native species of Provincial Conservation Concern (S1)]

Festuca brevipila Tracey 

(F. trachyphylla (Hackel) Krajina; F. longifolia auct.; F. ovina, auct.)


Sheep Fescue


Festuca filiformis Pourr.

( F. capillata Lam.; F. tenuifolia Lam.)


Hair Fescue


Festuca rubra L. 


Red Fescue


Festuca subverticillata (Pers.) Alexeev

( F. obtusa Biehler)


Nodding Fescue


Glyceria borealis (Nash) Batch.


Northern Manna Grass


Glyceria canadensis (Michx.) Trin.


Canada Manna Grass

RS (3): Mer Bleue CA*; Mud Creek; Albion Wetland

Glyceria grandis S. Wats.


Large Manna Grass


Glyceria ×laxa (Scribn.) Scribn

(G. canadensis (Michx.) Trin. x grandis S. Wats.)


hybrid Manna Grass

RS (Historic): old record, Mer Bleue CA*

Glyceria maxima (Hartm.) Holmb.    


Giant Manna Grass

Rare (Mississippi R.)

Glyceria melicaria (Michx.) Hubb.


Long Manna Grass

RS (3): Mer Bleue CA; Vars East; Chapel Hill Forest.

Glyceria ×ottawensis Bowden

( G. canadensis (Michx.) Trin. x striata (Lam.) A. Hitchc.)


hybrid Manna Grass


Glyceria septentrionalis A. Hitchc. 


Southern Manna Grass

RS (1): Lower Duck Island.

Glyceria striata (Lam.) A. Hitchc.


Fowl Manna Grass


Hordeum jubatum L.


Foxtail Barley


Hordeum vulgare L. 




Leersia oryzoides (L.) Sw.


Rice Cut-grass


Leersia virginica Willd.


Virginia Cut-grass


Lolium arundinaceum (Schreb.) Darbyshire

(Festuca arundinacea Schreb.)


Tall Fescue


Lolium perenne L. 

(incl. Lolium multiflorum Lam.)


Perennial Rye grass


Lolium pratense (Hudson)  Darbyshire 

(Festuca pratensis Hudson)


Meadow Fescue

Common (local)

Milium effusum L.


Wild Millet

RS (10*): Morris Island (Lavergne Point); South March Highlands (Trillium Woods) Osgoode Swamp*; Navan; O'Toole Road; Emmett Road; French Hill Creek; Magladry Road South; Bearbrook; Vars East.

Miscanthus sacchariflorus (Maxim.) Hackel




Molinia caerulea (L.) Moench 


Moor Grass


Muhlenbergia frondosa (Poir.) Fern.


Wire-stem Muhlenbergia

RS (4): Deschenes Lookout; Rockcliffe; Petrie Islands; Edwards [plus adventives].

Muhlenbergia glomerata (Willd.) Trin.


Wild Timothy

Uncommon [11] (plus adventives)

Muhlenbergia mexicana (L.) Trin.


Mexican Muhlenbergia


Muhlenbergia sylvatica Torr. ex A. Gray


Woodland Muhlenbergia

Provincial Conservation Concern (S1); RS (4): Rockcliffe Park ESA; Vincent Massey Park; Billings Bridge Islands ESA; Navan.

Oryzopsis asperifolia Michx.


Mountain Rice Grass


Oryzopsis pungens (Torr. ex Spreng.) Hitchc.


Sharp-leaved Mountain Rice Grass

RS (3): Constance Bay Sand Hills (common); Kanata; Vars West.

Oryzopsis racemosa (Sm.) Ricker ex Hitchc.


Mountain Rice Grass

Uncommon [17]

Panicum capillare L.


Witch Grass


Panicum dichotomiflorum Michx. 


Panic Grass


Panicum flexile (Gatt.) Scribn.


Wiry Panic Grass

Uncommon (locally abundant)

Panicum miliaceum L. 




Panicum philadelphicum Bernh. ex Trin.


Philadelphia Panic Grass

Uncommon (locally abundant)

Panicum philadelphicum Bernh. ex Trin. ssp. gattingeri (Nash) Freckmann & Long

(P. gattingeri Nash)


Gattinger's Panic Grass

Provincial Conservation Concern (S3); RS (1): Petrie Islands

Panicum tuckermanii Fern.

(P. philadelphicum Bernh. ex Trin., p. pt.)


Tuckerman's Panic Grass

RS (7): Petrie Islands; Morris Island; Constance Bay Shores; Shirleys Bay (Innis Point); Britannia CA; Upper Jock River; Carp Airport; Highway 7 North.

Panicum virgatum L.  


Switch Grass

Rare [native elsewhere in Ontario]

Phalaris arundinacea L. 


Reed Canary Grass

Common (locally abundant introduction)

Phalaris canariensis L. 


Bird-seed Grass


Phleum pratense L. 




Phragmites australis (Cav.) Trin. ex Steudel ssp. americana Saltonstall, Peterson & Sorong


Common Reed Grass

RS (8*): Shirleys Bay; Mississippi River*; Upper Jock River;;  Prospect;  Mer Bleue CA;   Mud Pond; Albion Wetland*; Marlborough Forest.

Phragmites australis (Cav.) Trin. ex Steudel ssp. australis  


European Reed Grass

Uncommon (locally abundant adventive)

Poa alsodes A. Gray


Woodland Meadow Grass

RS (4): Kinburn Clay Plain Woods; Osgoode Swamp; Ont. Land Corp.; South Gloucester.

Poa annua L. 


Annual Meadow Grass


Poa bulbosa L.


Bulbous Meadow Grass


Poa compressa L. 


Wire Grass


Poa glaucantha Gaudin


Blue Meadow Grass

RS (Historic): old record, Cumberland.

 Poa nemoralis L. 


Wood Meadow Grass


Poa palustris L.


Swamp Meadow Grass


Poa pratensis L. 


June Meadow Grass


Poa saltuensis Fern. & Wieg.


Forest Meadow Grass

RS (6*): South March Highlands*; Buchans Bay West; Stony Swamp CA; Carlsbad Springs SW; South Gloucester; DND Woods.

Poa trivialis L. 


Rough Meadow Grass


Puccinellia distans (Jacq.) Parl. 


Alkakli Grass


Schizachne purpurascens (Torr.) Swallen


False Melic Grass


Schizachyrium scoparium (Michx.) Nees

 (Andropogon scoparius Michx.)


Little Bluestem

RS (7*): Morris Island*; Fitzroy Provincial Park;  Shirleys Bay*; Crystal Bay; Britannia CA (extirpated); Baskins Beach; Constance Bay shores [* adventives].

Secale cereale L. 




Setaria faberi Herrm. 


Large Bristlegrass


Setaria italica (L.) Beauv. 


Italian Bristlegrass


Setaria pumila (Poir.) Roemer & Schultes 

 (S. glauca (L.) Beauv.) 


Pigeon Grass


Setaria verticillata (L.) Beauv. 


Bur Bristlegrass


Setaria viridis (L.) Beauv. 


Green Bristlegrass


Sorghastrum nutans (L.) Nash


Indian Grass

RS (6*): Morris Island*; Constance Bay Shores* (common); Fitzroy Provincial Park; Andrew Haydon Park; Shirleys Bay*; Crystal Bay.

Sorghum bicolor Moench ssp. drummondii (Steudl.) de Wet & Harlan 

(S. sudanense (Piper) Stapf.)


Sudan Grass


Spartina pectinata Link


Cord Grass

Uncommon (common along Ottawa River)

Sphenopholis intermedia (Rydb.) Rydb.


Slender Wedge Grass

Uncommon [17]

Sporobolus compositus (Poir.) Merr.

(Sporobolus asper (Michx.) Kunth)



Provincial Conservation Concern (S1S2); RS (1): Shirleys Bay (Innis Point) [plus roadside adventives].

Sporobolus cryptandrus (Torr.) A. Gray   


Sand Dropseed

Rare (locally abundant)

Sporobolus heterolepis (A. Gray) A. Gray


Prairie Dropseed

Provincial Conservation Concern (S2); RS (3*):  Burnt Lands* (locally abundant); Shirleys Bay (Innis Point - extirpated?); Morris Island (Lavergne Bay).

Sporobolus neglectus Nash


Overlooked Dropseed


Sporobolus vaginiflorus (Torr. ex A. Gray) Wood (s.l.)


Ensheathed Dropseed

Common [taxonomic problem; var. vaginiflorus rare on alvars ?].

Torreyochloa pallida (Torr.) Church var. fernaldii (A. Hitchc.) Dore

(T. fernaldii (A. Hitchc.) Church )


Fernald's Manna Grass

RS (4): Mer Bleue CA; South March Highlands; Stony Swamp CA; Fitzroy Prov Park.

Torreyochloa pallida (Torr.) Church var. pallida


Pale Manna Grass

Provincial Conservation Concern (S2); RS (2): Ont. Land Corp; Albion Road South.

Trisetum spicatum (L.) Richter

(incl. T. triflorum (Bigel.) A. & D. Löve)


False Oats

RS (Historic): old record, Rockcliffe.

Triticum aestivum L. 




Ventenata dubia (Leers) Cosson 




Zea mays L. 




Zizania aquatica L.

(incl. Z. aquatica var. subbrevis Boivin)


Southern Wild Rice

RS (6*): Mer Bleue CA; Ont. Land Corp.; Bear Brook* (common); North Castor River (common); North Osgoode Complex; Vars.

Zizania palustris L. var. palustris


Wild Rice


Zizania palustris L. var. interior (Fassett) Dore 


Western Wild Rice

Rare [native elsewhere in Ontario]

CYPERACEAE (Sedge Family)

Bolboschoenus fluviatilis (Torr.) Sojak

(Schoenoplectus fluviatilis (Torr.) Strong; Scirpus fluviatilis (Torr.) A. Gray)


River Bulrush

Uncommon [15]

Bulbostylis capillaris (L.)  C. B. Clarke 



Rare [native populations of Provincial Conservation Concern (S3?) in Ontario]

Carex acutiformis Ehrh. 




Carex albursina Sheld.


White-bear Sedge

Uncommon [16]

Carex alopecoidea Tuckerm.


Foxtail Sedge

RS (8): Stony Swamp CA; Manotick ANSI; Stillwater Creek; Third Line West Carleton Woodlot; Champlain Bridge; Elmhurst Street Woods; Severn Street Woods; NRC Woods.

Carex aquatilis Wahl.


Aquatic Sedge

RS (9*): Britannia CA; Champlain Bridge; Chaudiere Rapids; North of Highway 7; Poole Creek Wetland Complex; Duck Islands; Marlborough Forest*; French Hill Swamp; Vars East.

Carex arcta Boott


Bear Sedge

RS (Historic): old records, Vincent Massey Park; Britannia; Constance Bay Sand Hills.

Carex arctata Boott


Compressed Sedge


Carex atherodes Sprengel


Awned Sedge

RS (3): Stony Swamp CA; Osgoode Swamp (Springhill Bog); Burnt Lands.

Carex aurea Nutt.


Golden Sedge

Uncommon (locally abundant)

Carex backii Boott


Back's Sedge

RS (2): South March Highlands; Riverside Park.

Carex bebbii (Bailey) Fern.


Bebb's Sedge


Carex blanda Dew.


Smooth Sedge


Carex brevior (Dew.) Mack.


Short-headed Sedge

RS (4): Ont. Land Corp.; Vars West; Petrie Islands; South March Highlands.

Carex bromoides Willd.


Brome-like Sedge


Carex brunnescens (Pers.) Poir.


Brownish Sedge

Uncommon [12]

Carex canescens L.


Hoary Sedge

Uncommon [16]

Carex castanea Wahl.


Chestnut Sedge


Carex cephaloidea (Dew.) Dew.


Head Sedge

Uncommon [20]

Carex chordorrhiza L.f.


Cord Sedge

RS (2): Mer Bleue CA; Long Swamp.

Carex communis Bailey


Common Sedge


Carex comosa Boott


Bristly Sedge


Carex concinna R. Br.


Elegant Sedge

RS (Historic): old records, Buchans Bay West; Constance Lake; The Burnt Lands.

Carex crawei Dew.


Crawe's Sedge

RS (6*): The Burnt Lands* (common); Shirleys Bay (Innis Point); Morris Island (Lavergne Bay); Marathon Forest; Panmure Alvar; Burritts Rapids.

Carex crawfordii Fern.


Crawford's Sedge

RS (1): Carp Hills (West Ridge).

Carex crinita Lam.


Fringed Sedge


Carex cristatella Britt.


Crested Sedge


Carex cryptolepis Mack.


Hidden-scale Sedge

RS (3): Marlborough Forest (Richmond Fen); The Burnt Lands; Moores Corners; Fernbank Wetland.

Carex cumulata (Bailey) Mack.


Clustered Sedge

RS (2): Heron Gate Woods; Osgoode Swamp (Springhill Bog).

Carex debilis Michx. var. rudgei Bailey


Weak Sedge

RS (8*): Albion Wetland; Pinhey Forest; Pine Grove Forest; Ont. Land Corp.; Greely*; Vars West; Mer Bleue CA.

Carex deflexa Hornem.


Deflexed Sedge

RS (3): Britannia CA; Airbase Woods; Carp Hills (West Ridge).

Carex deweyana Schw.


Dewey's Sedge


Carex diandra Schrank


Two-stamened Sedge


Carex disperma Dew.


Two-seeded Sedge


Carex eburnea Boott


Ivory Sedge


Carex echinata Murr.


Prickly Sedge

RS (8*): Mer Bleue CA* (common); Albion Wetland; Pine Grove Forest; Stony Swamp CA; Carp Hills (Carp Barrens); South March Highlands; Vars West;  Ont. Land Corp. (several).

Carex exilis Dew.


Starved Sedge

RS (3*): Mer Bleue CA* (common); Marlborough Forest (Richmond Fen); Long Swamp.

Carex flacca Schreb. 


Heath Sedge


Carex flava L.


Yellow Sedge


Carex foenea Willd.

(C. aenea Fern.)


Copper Sedge

RS (6*): Hunt Club Creek; Mer Bleue CA; Ont. Land Corp.*; Pine Grove Forest; Petrie Islands; Carp Hills (Carp Barrens) [plus adventives].

Carex folliculata L. 


Long Sedge

Provincial Conservation Concern (S3); RS (10): Mer Bleue CA; Bypass Woods; Vars West; Baxter CA; Pinhey Forest; Petrie Islands; Anderson Road; Navan;  Magladry Road South; Ont. Land Corp.

Carex formosa Dew. 


Handsome Sedge

Provincial Conservation Concern (S3); Uncommon (14): Metcalfe;  Marlborough Forest (Flood Road); West Osgoode Swamp; NW Vernon; Vernon Woods; Springhill; South Castor River W; North Osgoode Complex; Metcalfe North;  8th Line N; Pana Road.; Rideau Carleton Woods; Hazeldean Park Woods.

Carex gracillima Schw.


Filiform Sedge


Carex granularis Willd.


Granular Sedge


Carex grayi Carey


Gray's Sedge

Uncommon [18]

Carex grisea Wahl.

(C. amphibola Steudel var. turgida Fern.)


Gray Sedge

RS (7*): Britannia CA*; Elmhurst Street Woods*; Shirleys Bay (Shirley’s Brook); Stillwater Creek*; North Gower; Champlain Bridge; Hearts Desire.

Carex gynandra Schw.



RS (3): Mer Bleue CA; French Hill Creek; Mud Creek.

Carex gynocrates Wormsk. ex Drejer


Ridged Sedge

RS (1): Albion Wetland.

Carex haydenii Dew.


Cloud Sedge

Provincial Conservation Concern (S2); RS (1): Carlsbad Springs SW.

Carex hirtifolia Mack.


Hairy Sedge

Uncommon [16]

Carex hitchcockiana Dew.


Hitchcock's Sedge

Uncommon [20]

Carex houghtoniana Torr. ex Dew.


Houghton's Sedge

RS (7); Baskins Beach; Constance Bay Sand Hills; The Burnt Lands; Stony Swamp CA; Vincent Massey Park; Bruce Pit Woods; Mer Bleue CA.

Carex hystericina Willd.


Porcupine Sedge


Carex interior Bailey


Inland Sedge


Carex intumescens Rudge


Bladder Sedge


Carex ×knieskernii Dew.

(C. arctata Boott x castanea Wahl.)


hybrid sedge


Carex lacustris Willd.


Lake Sedge


Carex lasiocarpa Ehrh.


Slender Sedge

Uncommon (locally abundant)

Carex laxiflora Lam.


Loose-flowered Sedge

Uncommon (Rare west of Rideau River)

Carex lenticularis Michx.


Flat-seeded Sedge

RS (6): Champlain Bridge; Constance Bay Shores; Britannia CA; Deschenes Lookout; Shirleys Bay (Innis Point); Fitzroy Provincial Park.

Carex leptalea Wahl.


Bristle-stalked Sedge


Carex leptonervia Fern.


Finely-nerved Sedge


Carex limosa L.


Mud Sedge

RS (5*): Mer Bleue CA; Marlborough Forest* (Richmond Fen (common); Phragmites Fen); Long Swamp; Albion Wetland; Osgoode Swamp* (Herberts Corners Bog).

Carex livida (Wahl.) Willd.


Lead Sedge

RS (3*): Long Swamp; Albion Wetland;  Marlborough Forest* (Richmond Fen; Phragmites Fen).

Carex lucorum Link


Distant Sedge

RS (Extirpated): old record, Billings Bridge.

Carex lupulina Willd.


Hop Sedge


Carex lurida Wahl.


Sallow Sedge

Uncommon [15]

Carex magellanica Lam.

(C. paupercula Michx.)


Stunted Sedge

Uncommon [13]

Carex merritt-fernaldii Mack.


Fernald's Sedge

RS (6*): Carp Hills (Carp Barrens*); Hunt Club Creek; Mer Bleue CA; Shirleys Bay (Innis Point); Bruce Pit Woods.

Carex molesta Mack.


Troublesome Sedge

RS (1): Fitzroy Provincial Park.

Carex novae-angliae Schw.


New England Sedge

Provincial Conservation Concern (S3); Uncommon (12): Mer Bleue CA *; Old Dump Woods; Bypass Woods; Albion Wetland; Vars West; Vars East; Osgoode Swamp (Herberts Corners Bog); North Castor River; French Hill Swamp;  Anderson Road; Carlsbad Springs SW.

Carex oligosperma Michx.


Few-seeded Sedge

RS (3): Mer Bleue CA; Osgoode Swamp (Herberts Corners Bog); Constance Bay Sand Hills.

Carex ormostachya Wieg.


Necklace Sedge

RS (3): Dwyer Hill; South Gloucester; Stittsville.

Carex pallescens L.


Pale Sedge


Carex pauciflora Lightf.


Few-flowered Sedge

RS (2*): Mer Bleue CA*; Marlborough Forest.

Carex peckii Howe


Peck's Sedge


Carex pedunculata Willd.


Peduncled Sedge


Carex pellita Muhl.

(C. lanuginosa, auct.)


Woolly Sedge

Uncommon (locally abundant)

Carex pensylvanica Lam.


Pennsylvania Sedge


Carex plantaginea Lam.


Plantain-leaved Sedge


Carex platyphylla Dew.


Broad-leaved Sedge

RS (Historic): old record, Woodridge.

Carex praegracilis W. Boott   


Slender Sedge

Uncommon (locally abundant; spreading)

Carex prairea Dew.


Prairie Sedge

RS (2): Albion Wetland; Long Swamp.

Carex prasina Wahl.


Onion Sedge

RS (10): Elmhurst St. Woods; Vars West; Billings Bridge; Magladry Road South; Cambrian Road; Vars East; Ont. Land Corp.; Anderson Road; DND Woods; Chapel Hill Forest.

Carex projecta Mack.


Spreading Sedge


Carex pseudo-cyperus L.


Cypress-like Sedge


Carex radiata (Wahl.) Small

(C. rosea, auct., non Willd.)


Stellate Sedge


Carex retrorsa Schw.


Back-turned Sedge


Carex richardsonii R. Br.


Richardson's Sedge

RS (2*): Constance Bay Sand Hills; The Burnt Lands* (common).

Carex rosea Schkuhr ex Willd.

(C. convoluta Mack.)


Rolled-up Sedge


Carex sartwellii Dew.


Sartwell's Sedge

RS (Historic): old record, Mer Bleue CA .

Carex scabrata Schw.


Scabrous Sedge


Carex scoparia Willd.


Broom Sedge

RS (9*): Carp Hills* (West Ridge; Carp Barrens); South March Highlands; Whelan Park; Mer Bleue CA; Albion Wetland; South Gloucester; Conroy Woods; Mud Pond; Town Centre Woods*.

Carex siccata Dew.

(C. foenea, auct., non Willd.)


Dry Sedge

RS (1*): Constance Bay Sand Hills* (common).

Carex sparganioides Willd.


Bur-reed Sedge

Uncommon [11]

Carex spicata Huds. 


Spiked Sedge


Carex sprengelii Dew. ex Sprengel


Sprengel's Sedge


Carex sterilis Willd.


Sterile Sedge

RS (1): Albion Wetland.

Carex stipata Willd.


Crowded Sedge


Carex stricta Lam.


Stiff Sedge

Uncommon  [11]

Carex xsubviridula (Kuken.) Fern.

(C. flava L. x viridula Michx.))


Hybrid sedge

Rare (Ashton Station)

Carex sychnocephala Carey


Compact Sedge

RS (8): Manotick; Stony Swamp CA; Constance Bay Sand Hills; North Osgoode Complex; Marlborough Forest; Albion Wetland; 8th Line N; South Gloucester.

Carex tenera Dew.


Slender Sedge


Carex tenuiflora Wahl.


Sparse-flowered Sedge

RS (1): Long Swamp.

Carex tonsa (Fern.) Bickn. var. rugosperma (Mack.) Crins

(C. rugosperma Mack.)


Rough-seeded Sedge


Carex tribuloides Wahl.


Blunt-broom Sedge


Carex trisperma Dew.  var. billingsii Knight


Billing’s Sedge

RS (1): Osgoode Swamp

Carex trisperma Dew. var. trisperma


Three-seeded Sedge

Uncommon [15]

Carex tuckermanii  Boott ex Dew.


Tuckerman's Sedge


Carex typhina Michx.


Cat-tail Sedge

Provincial Conservation Concern (S2); RS (3): Greens Creek CA; Britannia CA; Petrie Islands.

Carex umbellata Willd.


Umbrella Sedge

RS (6*): The Burnt Lands*; Metcalfe; Kanata; Baskins Beach; Antrim; Marlborough Forest.

Carex utriculata Boott

(C. rostrata Stokes var. utriculata (Boot) Bailey)


Beaked Sedge

RS (7*): Marlborough Forest (Rideau Tp.); Upper Duck Island; Vincent Massey Park; Mer Bleue CA.; Pine Grove Forest; Ont. Land Corp.; Shirleys Bay* (Watts Creek; Innis Point); Fitzroy Provincial Park.

Carex utriculata Boott x vesicaria L.


hybrid sedge

RS (1): Mer Bleue CA

Carex vaginata Tausch


Ensheathed Sedge

RS (3): Long Swamp; Corkery Wetland; Highway 17 North.

Carex vesicaria L.


Inflated Sedge

Uncommon [15]

Carex viridula Michx.


Greenish Sedge


Carex vulpinoidea Michx.


Fox Sedge


Carex woodii Dew.


Wood's Sedge

RS (6): Kinburn Clay Plain Woods; South Gloucester; Vernon Woods; Little's Woods; Pana Road; vicinity of Metcalfe.

Cladium mariscoides (Muhl.) Torr.



RS (3*): Marlborough Forest* (south end; Richmond Fen; Phragmites Fen); Mud Pond;  Albion Wetland.

Cyperus bipartitus Torr.

(C. rivularis Kunth)


River Umbrella-sedge


Cyperus diandrus Torr.


Two-stamened Umbrella-sedge

RS (7): Britannia CA; Ottawa Beach; Buchans Bay; Champlain Bridge; Woodridge; Fitzroy Harbour; Petrie Islands.

Cyperus esculentus L. var. leptostachyus Boeckl.





Cyperus houghtonii Torr.


Houghton's Umbrella-sedge

Provincial Conservation Concern (S3); RS (1*): Constance Bay Sand Hills (common).

Cyperus lupulinus (Spreng.) Marcks ssp. macilentus (Fern.) Marcks

(C. filiculmis, auct., non Vahl)


Slender Umbrella-sedge

RS (2*): Constance Bay Shores* (common); Constance Bay Sand Hills.

Cyperus odoratus L.

(incl. C. engelmannii Steudel; C.  ferruginescens, auct., non Boeck.)



RS (2): Horseshoe Bay; Petrie Islands.

Cyperus squarrosus L.

(C. aristatus Rottb.)


Awned Bulrush


Cyperus strigosus L.


Lean Umbrella-sedge

Uncommon [11]

Dulichium arundinaceum (L.) Britt.


Three-way Sedge


Eleocharis acicularis (L.) R.& S.


Needle Spikerush


Eleocharis compressa Sull.

(incl. E. elliptica auct., non Kunth ?)



Flattened Spikerush

Uncommon  [11] (taxonomic problem)

 Eleocharis elliptica Kunth

(E. tenuis (Willd.) Schultes var. borealis (Svenson) Boivin; E. compressa auct., non Sull.?)


Rounded Spike-rush

Uncommon  [12] (taxonomic problem)

Eleocharis erythropoda Steudel

(E. calva Torr.)


Red-stemmed Spike-rush


Eleocharis intermedia Schultes


Intermediate Spike-rush

RS (3): Britannia Bay; Ottawa Beach; South Gloucester.

Eleocharis obtusa (Willd.) Schultes


Blunt Spike-rush


Eleocharis palustris (L.) R.& S.

(incl. E. smallii Britt.)


Marsh Spike-rush


Eriophorum chamissonis C. Meyer


Chamisso's Cotton-grass

RS (1*): Mer Bleue CA* (common).

Eriophorum gracile Koch


Slender Cotton-grass

RS (1*): Marlborough Forest*.

Eriophorum ×porsildii Raymond

(E. chamissonis C. Meyer x vaginatum L.)


Porsild's Cotton-grass

RS (Historic): old record, Mer Bleue CA.

Eriophorum tenellum Nutt.


Filiform Cotton-grass

RS (1*): Mer Bleue CA* (common).

Eriophorum vaginatum L.

(E. spissum Fern.)


Dense Cotton-grass

RS (3*): Mer Bleue CA* (abundant); Osgoode Swamp* (Springhill Bog, Herberts Corners Bog); Marlborough Forest*.

Eriophorum virginicum L.


Virginia Cotton-grass

RS (6*): Mer Bleue CA* (common); Pine Grove Forest; Stony Swamp CA; Osgoode Swamp* (Springhill Bog; Herberts Corners Bog); Vars East.

Eriophorum viridicarinatum (Engelm.) Fern.


Green Cotton-grass

RS (9*): Mud Pond; Marlborough Forest* (south end; Phragmites Fen; Richmond Fen); Mer Bleue CA; Long Swamp;  Corkery Wetland; Albion Wetland; Stony Swamp CA; Osgoode Swamp; Poole Creek Wetland.

Fimbristylis autumnalis (L.) R.& S.


Autumn Fimbristylis

RS (5): Constance Bay Shores; Horseshoe Bay; Fitzroy Provincial Park; Champlain Bridge; Petrie Islands.

Rhynchospora alba (L.) Vahl


White Beak-rush

RS (5*): Marlborough Forest* (Richmond Fen; Phragmites Fen); Long Swamp; Mud Pond; Albion Wetland; Mer Bleue CA* (common).

Schoenoplectus acutus (Muhl. ex Bigel.) Love & Love

(Scirpus acutus (Sm.) Hartm.)


Great Bulrush

RS (5*): Marlborough Forest*; Billings Bridge; Champlain Bridge; Vincent Massey Park; Constance Bay Shores.

Schoenoplectus heterochaetus (Chase) Sojak

(Scirpus heterochaetus Chase)


 Slender Bulrush

Provincial Conservation Concern (S2); RS (Extirpated): old record, Green Island, Rideau River.

Schoenoplectus pungens (Vahl) Palla

(Scirpus americanus auct., non Pers.; S. pungens Vahl)


Three-square Bulrush


Schoenoplectus tabernaemontani (Gmel.) Palla

(Scirpus validus Vahl)


Strong Bulrush


Scirpus atrocintus Fern.


Black-girdled Bulrush


Scirpus atrovirens Willd.


Blackish Bulrush


Scirpus cyperinus (L.) Kunth




Scirpus hattorianus Fern.

(S. atrovirens Willd., p. pt.)


Mosquito Bulrush


Scirpus microcarpus Presl.

 (S. rubrotinctus Fern.)


Red-stem Bulrush


Scirpus pedicellatus Fern.


Pedicled Bulrush

RS (4): Albion Wetland; South Gloucester; Shirleys Bay (Watts Creek), Petrie Islands.

Scirpus pendulus Muhl.

(S. lineatus auct., non  Michx.)


Drooping Bulrush

Uncommon (locally abundant).

Trichophorum alpinum (L.) Pers.

(Scirpus hudsonianus (Michx.) Fern.)


Wooly Club-rush

RS (9*): Marlborough Forest* (south end; Richmond Fen; Phragmites Fen); Long Swamp; Mud Pond; Mer Bleue CA; Albion Wetland; Pine Grove Forest; Ont. Land Corp. [plus adventives].

ACORACEAE  (Sweet-flag Family)

Acorus americanus Raf.

(A. calamus auct., non L.)




ARACEAE  (Arum Family)

Arisaema triphyllum (L.) Schott




Calla palustris L.


Wild Calla


Symplocarpus foetidus (L.) Nutt.



RS (5): Osgoode; Sarsfield; Metcalfe North;  MacSkimming Woods; French Hill Swamp (*)

- also introduced (South Gloucester).

LEMNACEAE  (Duckweed Family)

Lemna minor L.


Small Duckweed


Lemna trisulca L.


Ivy Duckweed


Spirodela polyrhiza (L.) Schleid.


Large Duckweed

RS (7*): Britannia CA; Upper Jock River; Fitzroy Harbour (Carp River); Shirley's Bay* (Watts Creek; Innis Point); Kars (Rideau River); Vincent Massey Park; Memorial Gardens Woods.

Wolffia borealis (Engelm.) Land.

 (W. punctata Griseb.)



Uncommon [15]

Wolffia columbiana H. Karsten

(W. arrhiza auct., non (L.) Horkel)



Uncommon [15]

ERIOCAULACEAE (Pipewort Family)

Eriocaulon aquaticum (Hill) Druce

(E. septangulare With.)



Uncommon (locally abundant)


COMMELINACEAE (Spiderwort Family)

Commelina communis L. 




PONTEDERIACEAE (Pickerelweed Family)

Pontederia cordata L.




Zosterella dubia (Jacq.) Small

(Heteranthera dubia (Jacq.) MacM.)


Water Stargrass

Uncommon (locally abundant)

JUNCACEAE (Rush Family)

Juncus alpinoarticulatus Chaix.

(J. alpinus Vill., p. pt.)


Alpine Rush

RS (9*): The Burnt Lands; Marlborough Forest*; Britannia Bay; Magladry Road South; South Gloucester; Shirleys Bay; Burritts Rapids; Fernbank Wetland; Champlain Bridge.

Juncus articulatus L.


Jointed Rush

Uncommon [ 12]


Juncus arcticus Willd. var. balticus (Willd.) Traut.

(J. balticus Willd.)


Baltic Rush

Uncommon [native elsewhere in Ontario]

Juncus brevicaudatus (Engelm.) Fern.




Juncus bufonius L.


Toad Rush