Species at risk by type

A list of species at risk for the selected Ontario region.

Plants and Lichens

  • gattingers-agalinis

    Gattinger's Agalinis (Agalinis gattingeri)

    Status: endangered

    Gattinger's Agalinis looks so similar to its close relative, Skinner's Agalinis, that it can only be distinguished by experts who closely analyze specific features of the flowers, leaves and stems.

  • skinners-agalinis

    Skinner's Agalinis (Agalinis skinneriana)

    Status: endangered

    Skinner's Agalinis is able to steal nutrients from other plants. It uses a fungus to attach its own roots to the roots of its host plant, and is then able to leech nutrients and water out of the plant.

  • colicroot

    Colicroot (Aletris farinosa)

    Status: endangered

    Colicroot is also known as Ague root because it was used to treat some fevers, which were often referred to as ague in Middle English.

  • scarlet-ammannia

    Scarlet Ammannia (Ammannia robusta)

    Status: endangered

    In British Columbia, Scarlet Ammannia is found alongside another species at risk, Toothcup (Rotala ramosior). While these species are also both found in Ontario, they do not occur together here.

  • forked-three-awned-grass

    Forked Three-awned Grass (Aristida basiramea)

    Status: endangered

    Since Forked Three-awned Grass is an annual, its growth and reproduction are influenced by each year's environmental conditions. This makes estimating population size difficult, as a number of plants present in an area may remain relatively undetectable in the soil seed bank during any given year.

  • four-leaved-milkweed

    Four-leaved Milkweed (Asclepias quadrifolia)

    Status: endangered

    The two populations of Four-leaved Milkweed which are known to still exist in Ontario were only recently discovered - in 2006 and 2007. It is possible that additional populations may be identified in the future.

  • cherry-birch

    Cherry Birch (Betula lenta)

    Status: endangered

    A Cherry Birch tree can live for 265 years or longer.

  • spoon-leaved-moss

    Spoon-leaved Moss (Bryoandersonia illecebra)

    Status: endangered

    A previously unknown population of Spoon-leaved Moss was discovered in Welland County in 2002.

  • bluehearts

    Bluehearts (Buchnera americana)

    Status: endangered

    The seeds of Bluehearts require light to germinate. As a result, the species depends on disturbances such as fire and water level fluctuations to prevent shade-producing vegetation, trees and shrubs from taking over their habitat.

  • juniper-sedge

    Juniper Sedge (Carex juniperorum)

    Status: endangered

    This species is new to science. The biology of the Juniper Sedge is not well known, since the plant was only discovered in Ontario in the early 1990s.

  • false-hop-sedge

    False Hop Sedge (Carex lupuliformis)

    Status: endangered

    The tiny flowers of False Hop Sedge are wind pollinated, so the plant does not attract many insects. However, the caterpillars of various butterflies, skippers, and moths feed on various sedge species, while a number of species of birds feed on the seeds.

  • american-chestnut

    American Chestnut (Castanea dentata)

    Status: endangered

    People used the American Chestnut for treating numerous ailments (from coughs and dermatitis to heart trouble), as a staple food and beverage, to build shelters, for firewood and as a source of dye. Early settlers soon realized the many important uses of this tree.

  • spotted-wintergreen

    Spotted Wintergreen (Chimaphila maculata)

    Status: endangered

    Aboriginal peoples used Spotted Wintergreen for a variety of medicinal purposes including as a poultice, for rheumatism, and for the treatment of colds and fevers.

  • eastern-flowering-dogwood

    Eastern Flowering Dogwood (Cornus florida)

    Status: endangered

    The bright red fruit of this tree is poisonous to humans but can be eaten by over 50 species of birds and small mammals. These animals help distribute Eastern Flowering Dogwood seeds throughout forests.

  • small-white-ladys-slipper

    Small White Lady's-slipper (Cypripedium candidum)

    Status: endangered

    Individual Small White Lady's-slipper plants may not flower until as many as 16 years after germination.

  • horsetail-spike-rush

    Horsetail Spike-rush (Eleocharis equisetoides)

    Status: endangered

    Horsetail Spike-rush was used by the Seminole Indians to make beads for jewelry.

  • bent-spike-rush

    Bent Spike-rush (Eleocharis geniculata)

    Status: endangered

    This plant can store seeds in the soil for years waiting for the right conditions to grow.

  • american-columbo

    American Columbo (Frasera caroliniensis)

    Status: endangered

    American Columbo may live for many years but it flowers only once and then dies.

  • white-prairie-gentian

    White Prairie Gentian (Gentiana alba)

    Status: endangered

    Bumblebees are one of the few insects that are strong enough to open the White Prairie Gentian's flowers and pollinate them.

  • engelmanns-quillwort

    Engelmann's quillwort (Isoetes engelmannii)

    Status: endangered

    Researchers need to examine this plant under a microscope to tell the difference between different types of quillworts.

  • small-whorled-pogonia

    Small Whorled Pogonia (Isotria medeoloides)

    Status: endangered

    The Small Whorled Pogonia appears to be primarily self-pollinated. The flowers lack nectar guides and fragrance and insect pollination has not been observed.

  • large-whorled-pogonia

    Large Whorled Pogonia (Isotria verticillata)

    Status: endangered

    As do all orchids, Large Whorled Pogonia has a symbiotic relationship with fungus found in the soil, which means they are interdependent for nourishment and survival. The Large Whorled Pogonia will only produce seeds if the necessary fungus is present in the soil.

  • butternut

    Butternut (Juglans cinerea)

    Status: endangered

    Aboriginal people used this plant medicinally to treat toothaches, injuries and digestive problems.

  • slender-bush-clover

    Slender Bush-clover (Lespedeza virginica)

    Status: endangered

    Fire plays an important roll in maintaining the prairie habitat of Slender Bush-clover. Fire naturally removes trees, shrubs and many invasive plants that would otherwise shade-out prairie plants.

  • cucumber-tree

    Cucumber Tree (Magnolia acuminata)

    Status: endangered

    The Cucumber Tree gets its name from its fruit that is pickle-like in shape and changes from green to red as it ripens. Once ripe, the oily, scented seeds are exposed and hang by fine threads. It is assumed that birds are the main consumers and dispersers of these seeds.

  • red-mulberry

    Red Mulberry (Morus rubra)

    Status: endangered

    Unlike most fruit trees that are pollinated by insects, the flowers of this plant are pollinated by the wind.

  • eastern-prickly-pear-cactus

    Eastern Prickly Pear Cactus (Opuntia humifusa)

    Status: endangered

    Birds sometimes nest among the stems of the Eastern Prickly Pear Cactus, where spines of the cactus aid in protecting eggs and nestlings from predators.

  • american-ginseng

    American Ginseng (Panax quinquefolius)

    Status: endangered

    Aboriginal people have used American Ginseng for a wide range of medicinal purposes including treatment of headaches, earaches, rheumatism, convulsions, bleeding, fevers, vomiting, tuberculosis, gonorrhea and as a cure-all when other treatments failed.

  • pale-bellied-frost-lichen

    Pale-bellied Frost Lichen (Physconia subpallida)

    Status: endangered

    This lichen grows on the surface of other plants, rocks, or structures and derives nutrients from the air and rain.

  • heart-leaved-plantain

    Heart-leaved Plantain (Plantago cordata)

    Status: endangered

    Heart-leaved Plantain is capable of self-pollinating but generally the seeds are wind-pollinated.

  • eastern-prairie-fringed-orchid

    Eastern prairie fringed-orchid (Platanthera leucophaea)

    Status: endangered

    This orchid's seeds are produced in huge numbers, but germination and seedling growth depend on the presence of special fungi in the soil.

  • pink-milkwort

    Pink Milkwort (Polygala incarnata)

    Status: endangered

    Fire plays an important role in maintaining open prairie habitat where Pink Milkwort lives. Fire actually stimulates the growth of these hardy flowers and naturally removes trees and shrubs that would otherwise overtake its habitat.

  • ogdens-pondweed

    Ogden's Pondweed (Potamogeton ogdenii)

    Status: endangered

    Pondweeds provide habitat for aquatic invertebrates, food for mammals and waterfowl, and hiding places for amphibians and fish.

  • hoary-mountain-mint

    Hoary Mountain-mint (Pycnanthemum incanum)

    Status: endangered

    Hoary Mountain-mint is a very fragrant plant that is attractive to bees and known to produce high quality honey.

  • toothcup

    Lowland Toothcup (Rotala ramosior)

    Status: endangered

    The populations of Toothcup in Canada are believed to be post-glacial relicts - a once widespread natural population surviving only in isolated localities in British Columbia and Ontario because of environmental changes.

  • virginia-mallow

    Virginia Mallow (Sida hermaphrodita)

    Status: endangered

    In Poland and Russia, this plant is cultivated and used as biomass for creating energy and heat.

  • showy-goldenrod

    Showy Goldenrod (Great Lakes Plains population) (Solidago speciosa)

    Status: endangered

    The root of this species was used by Aboriginal people for burns, strained muscles, trouble breathing and difficult labour.

  • wood-poppy

    Wood-poppy (Stylophorum diphyllum)

    Status: endangered

    Wood-poppy seeds have an elaiosome, which is a fleshy structure that is rich in lipids and proteins. Ants, which are attracted to these elaiosomes, carry them back to their nests, feed them to their larvae, and then discard the intact seed. In doing this, the ants serve as dispersers of the Wood-poppy seeds.

  • western-silvery-aster

    Western Silvery Aster (Symphyotrichum sericeum)

    Status: endangered

    This plant is Ontario's rarest aster, growing in rare bur oak savannahs.

  • virginias-goats-rue

    Virginia Goat's-rue (Tephrosia virginiana)

    Status: endangered

    Virginia Goat's-rue has its own self-defence against pesky insects. The chemical rotenone has been found in the plant, a chemical that is used as an insecticide and piscicide.

  • few-flowered-club-rush

    Few-flowered club rush (Trichophorum planifolium)

    Status: endangered

    All Canadian populations of this plant have been found near openings in the forest canopy, suggesting that once the ground is heavily shaded, this sedge cannot survive.

  • drooping-trillium

    Drooping Trillium (Trillium flexipes)

    Status: endangered

    Drooping Trillium may take up to 10 years to produce flowers.

  • nodding-pogonia

    Nodding Pogonia (Triphora trianthophoros)

    Status: endangered

    Orchids can remain dormant in the soil before emerging when the conditions are suitable.

  • birds-foot-violet

    Bird's-foot Violet (Viola pedata)

    Status: endangered

    Bird's-foot Violet has a creative way to disperse seeds. The tiny seeds are contained inside a smooth green seedpod that bursts open and flings the seeds up to five metres away.

  • blunt-lobed-woodsia

    Blunt-lobed Woodsia (Woodsia obtusa)

    Status: endangered

    Blunt-lobed Woodsia may live as long as several decades.

  • spring-blue-eyed-mary

    Spring Blue-eyed Mary (Collinsia verna)

    Status: extirpated

    The plant's flowers are pollinated by bees, butterflies and flies.

  • illinois-tick-trefoil

    Illinois Tick-trefoil (Desmodium illinoense)

    Status: extirpated

    Illinois Tick-trefoil has explosive blossoms, which means that when a bee or butterfly stops on a flower, a cloud of pollen is shot at it.

  • incurved-grizzled-moss

    Incurved Grizzled Moss (Ptychomitrium incurvum)

    Status: extirpated


  • green-dragon

    Green Dragon (Arisaema dracontium)

    Status: special concern

    The Green Dragon's root is bitter tasting and poisonous unless specially prepared, but it was used medicinally by Aboriginal people and European settlers.

  • tuberous-indian-plantain

    Tuberous Indian-plantain (Arnoglossum plantagineum)

    Status: special concern

    Tuberous refers to the plant's fleshy, thickened roots.

  • american-harts-tongue-fern

    Hart's-tongue Fern (Asplenium scolopendrium)

    Status: special concern

    Hart's-tongue Fern has very specific habitat requirements, making transplantation and artificial propagation difficult.

  • swamp-rose-mallow

    Swamp Rose-mallow (Hibiscus moscheutos)

    Status: special concern

    The total Canadian population of Swamp Rose-mallow is estimated to consist of fewer than 10,000 plants.

  • dwarf-lake-iris

    Dwarf Lake Iris (Iris lacustris)

    Status: special concern

    Michigan recently designated the Dwarf Lake Iris as its official wildflower.

  • broad-beech-fern

    Broad Beech Fern (Phegopteris hexagonoptera)

    Status: special concern

    Broad Beech Fern reproduces through spores. The spores are contained in a case-like structure called a sporangium. The sporangia burst upon maturity at the end of summer and the spores are scattered through the air.

  • hills-pondweed

    Hill's Pondweed (Potamogeton hillii)

    Status: special concern

    Hill's Pondweed was not discovered in Ontario until 1951, but a specimen in the Canadian Museum of Nature was collected in 1901. More historical specimens may be discovered in Canadian collections.

  • common-hoptree

    Common Hoptree (Ptelea trifoliata)

    Status: special concern

    Common Hoptree is one of two native larval host plants for the rare Giant Swallowtail butterfly.

  • shumard-oak

    Shumard Oak (Quercus shumardii)

    Status: special concern

    The Shumard Oak's shiny, deep-lobed leaves help distinguish the species from the similar-looking Red Oak.

  • climbing-prairie-rose

    Climbing Prairie Rose (Rosa setigera)

    Status: special concern

    Climbing Prairie Rose is dioecious (having male and female reproductive structures on separate plants), which is unusual for rose species.

  • riddells-goldenrod

    Riddell's Goldenrod (Solidago riddellii)

    Status: special concern

    Riddell's Goldenrod has the potential to self-pollinate but it is primarily an out-breeder, pollinated by a variety of flies, bees, wasps, and moths.

  • crooked-stem-aster

    Crooked-stem Aster (Symphyotrichum prenanthoides)

    Status: special concern

    Bees and butterflies pollinate the flowers of the Crooked-stem Aster. The seeds are scattered by wind after ripening.

  • branched-bartonia

    Branched Bartonia (Bartonia paniculata)

    Status: threatened

    This plant's tiny fruits are only about four millimetres long, but each fruit contains 1,000 to 1,500 seeds.

  • wild-hyacinth

    Wild Hyacinth (Camassia scilloides)

    Status: threatened

    A single Wild Hyacinth can produce over 100 flowers in a single season.

  • dwarf-hackberry

    Dwarf Hackberry (Celtis tenuifolia)

    Status: threatened

    Many insects rely on the Dwarf Hackberry for survival. Several rare insects, including beetles that were only recently discovered in Canada, also depend on the Dwarf Hackberry for part of their life cycles.

  • hills-thistle

    Hill's Thistle (Cirsium hillii)

    Status: threatened

    In Ontario, Hill's Thistle often grows with other species at risk such as Lakeside Daisy and Houghton's Goldenrod.

  • pitchers-thistle

    Pitcher's Thistle (Cirsium pitcheri)

    Status: threatened

    Pitcher's Thistle was named after Dr. Zina Pitcher, who discovered the plant while serving as an army surgeon during the 1820s at Fort Brady, Sault Ste. Marie on Lake Superior.

  • false-rue-anemone

    False Rue-anemone (Enemion biternatum)

    Status: threatened

    Unlike other flowering plants, False Rue-anemone does not produce nectar to attract insects to pollinate its flowers. However, because it is one of the first plants to produce flowers in the spring, it is able to attract insects that don't yet have tastier options.

  • white-wood-aster

    White Wood Aster (Eurybia divaricata)

    Status: threatened

    The flowers of White Wood Aster are attractive to butterflies and it is the host plant for Pearly Crescents, a common North American butterfly.

  • blue-ash

    Blue Ash (Fraxinus quadrangulata)

    Status: threatened

    Blue Ash is named for the dye which can be extracted by mashing and cooking the inner trunk bark. It was used by First Nations and early European settlers.

  • kentucky-coffee-tree

    Kentucky Coffee-tree (Gymnocladus dioicus)

    Status: threatened

    The leaves and seeds of Kentucky Coffee-tree contain a toxic substance, the alkaloid, cytosine, which may be fatal if consumed. However, aboriginal people used the roasted seeds of the Kentucky Coffee-tree to treat headaches and relieve digestion problems. Roasting is supposed to neutralize the toxins.

  • goldenseal

    Goldenseal (Hydrastis canadensis)

    Status: threatened

    A tea made from the roots of Goldenseal was used in traditional aboriginal medicine to treat a variety of complaints including ulcerated or inflamed mucous membranes. This plant continues to be popular in herbal medicine today, but only farm-grown Goldenseal should be used owing to its extreme rarity in the wild.

  • american-water-willow

    American Water-willow (Justicia americana)

    Status: threatened

    American Water-willow (Latin name: Justicia americana) is named after James Justice who was an 18th century Scottish horticulturalist and botanist. Americana refers to the plant being native to the Americas.

  • dense-blazing-star

    Dense Blazing Star (Liatris spicata)

    Status: threatened

    Dense Blazing Star is able to grow in soil that is contaminated with cadmium by turning this toxic heavy metal into a non-toxic form in its tissues.

  • purple-twayblade

    Purple Twayblade (Liparis liliifolia)

    Status: threatened

    Purple Twayblade often grows in grassland savanna - one of the most endangered habitats in Canada. This extremely rare community supports an amazing diversity of wildlife, plants, butterflies and other insects.

  • small-flowered-lipocarpha

    Small-flowered Lipocarpha (Lipocarpha micrantha)

    Status: threatened

    This tiny plant has a very wide range. It is found all the way from Brazil to southern Canada, and in Africa.

  • round-leaved-greenbrier

    Round-leaved Greenbrier (Smilax rotundifolia)

    Status: threatened

    The seeds of Round-leaved Greenbrier can remain buried in the soil for at least three years while waiting for the right conditions to start growing a new plant.

  • houghtons-goldenrod

    Houghton's Goldenrod (Solidago houghtonii)

    Status: threatened

    Houghton's Goldenrod is thought to have evolved as a result of hybridization between two other goldenrod species and a subsequent increase in chromosome number.

  • showy-goldenrod

    Showy Goldenrod (Boreal population) (Solidago speciosa)

    Status: threatened

    The root of this species was used by Aboriginal people for burns, strained muscles, trouble breathing and difficult labour.

  • willowleaf-aster

    Willowleaf Aster (Symphyotrichum praealtum)

    Status: threatened

    Aboriginal people used Willowleaf Aster to treat stomach aches and injuries. They also smoked the dried leaves for good luck while hunting.

  • lakeside-daisy

    Lakeside Daisy (Tetraneuris herbacea)

    Status: threatened

    The Ontario populations of Lakeside Daisy constitute about 95 per cent of the populations existing in the world. Lakeside Daisy is one of very few plant species with most of its global range in Ontario.

  • deerberry

    Deerberry (Vaccinium stamineum)

    Status: threatened

    Efforts are being made at St. Lawrence Islands National Park to re-introduce Deerberry to other areas of the park where the habitat is suitable, in order to increase the overall numbers of the species. Related research is being carried out in partnership with universities.

Updated: January 30, 2018