Species At Risk

Eastern Prickly Pear Cactus

(Opuntia humifusa)


Eastern Prickly Pear Cactus
Eastern Prickly Pear Cactus occurrences map


The Eastern Prickly Pear Cactus is a perennial succulent cactus with jointed, rounded, but flattened, green stems, the segments of which are called “pads”. It may be horizontal or upright, growing up to 0.5 metres in height. Typical of most cacti, the pads are armed with barbed bristles and spines. Yellow, waxy flowers about two to three centimetres in diameter, with centres, bloom along the edges of the pads. The juicy, edible fruits are green, ripening to reddish-brown.

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In Canada, the Eastern Prickly Pear Cactus is found only in southern Ontario. There are two known locations, which are on sand spits along the shore of Lake Erie. Based on historical reports, this cactus may once have been marginally more widespread in areas near Lake Erie and Lake St. Clair.


The Eastern Prickly Pear Cactus grows in dry sandy areas that are relatively open and sunny. It cannot grow in complete shade. It is found on sandy openings on dry, sometimes forested, hillsides and in sand dunes near beaches.


The main threat to Eastern Prickly Pear Cactus is habitat loss due to shoreline erosion and shading by trees and shrubs. It is also vulnerable to human interference from trampling, destruction of habitat and illegal collection for planting in gardens. Invasive plants such as Spotted Knapweed (Centaurea stoebe) and White Sweet-clover (Melilotus alba) out-compete Eastern Prickly Pear Cactus in Ontario.


Eastern Prickly Pear Cactus is protected under Ontario’s Endangered Species Act and the federal Species at Risk Act.

What You Can Do to help the Eastern Prickly Pear Cactus

  • The Ministry of Natural Resources tracks species at risk such as Eastern Prickly Pear Cactus. You can use a handy online form to report your sightings to the Natural Heritage Information Centre. Photographs with specific locations or mapping coordinates are always helpful. nhic.mnr.gov.on.ca
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Invasive species seriously threaten many of Ontario’s species at risk. To learn what you can do to help reduce the threat of invasive species, visit: ontario.ca/invasivespecies ; www.invadingspecies.com ; www.ontarioinvasiveplants.ca ; and, www.invasivespecies.gc.ca .
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.
  • Private land owners have a very important role to play in species recovery. You may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • The Canada-Ontario Farm Stewardship Program is available to farmers registered under the Canada-Ontario Environmental Farm Plan to encourage greater protection and conservation of habitat for species at risk. Find more information at www.omafra.gov.on.ca/english/environment/efp/efp.htm.

Did you know?

Ontario cacti rarely produce fruit and, instead, reproduce chiefly through pads breaking off parent plants and taking root nearby.

Did you know?

Small mammals, especially rabbits, are the main dispersers of the sweet-smelling fruits and seeds.

Did you know?

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.

Did you know?

Although very rare in Canada, the Eastern Prickly Pear Cactus is very common in the eastern United States where it is considered widespread, abundant and even weedy.

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.