|Eastern prickly pear|
As is the case in other Opuntia species, the green stems of this low-growing perennial cactus are flattened, and are formed of segments. Barbed bristles are found around the surfaces of the segments, and longer spines are sometimes present. The flowers are yellow to gold in color, and are found along the margins of mature segments. The flowers are waxy and sometimes have red centers. They measure 4–6 cm (1 5⁄8–2 3⁄8 in) across. This cactus blooms in the late spring.
The juicy and edible red or purple fruits measure from 3–5 cm (1 1⁄8–2 in). As the fruit matures, it changes colour from green to red, and often remains on the cactus until the following spring. There are 6 to 33 small, flat, light-colored seeds in each fruit.
Some botanists treat this cactus as a variety of Opuntia compressa: hence Opuntia compressa var. humifusa, or a synonym of Opuntia compressa. Those recognizing this species treat Opuntia rafinesquii as a junior synonym.
This species naturally occurs from arid areas of Montana southward to New Mexico, and eastward to the lower Great Lakes, and along the East Coast from the Florida Keys to coastal Connecticut. Its distribution in Canada is limited to the Carolinian forest in southern Ontario, specifically in Point Pelee National Park.
The Eastern prickly pear is the only native cactus species in Canada and is considered endangered, with only two small populations known to be persisting today. Their population range in southern Ontario has diminished over time due to succession by larger woody vegetation which shade out the cacti.
This plant is very intolerant of shade and instead thrives in sunny, hot and dry environments with well-draining, sandy soil. Opuntia humifusa will grow in open areas in sandy, rocky and coastal scrub habits. They are capable of surviving cool winters unlike many cacti, although harsh winter storms are known to cause habitat loss.
Close-up of yellow barbed bristles and longer spines
- "Opuntia humifusa". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 23 July 2015.
- "4. Opuntia humifusa", Flora of North America
- Niering, William A.; Olmstead, Nancy C. (1985) . The Audubon Society Field Guide to North American Wildflowers, Eastern Region. Knopf. p. 436. ISBN 0-394-50432-1.
- Eastern Prickly Pear Opuntia humifusa (PDF) (Report). Natural Heritage & Endangered Species Program, Massachusetts Division of Fisheries & Wildlife. Archived from the original (PDF) on September 21, 2018.
- "Species Profile (Eastern Prickly Pear Cactus) - Species at Risk Public Registry". wildlife-species.canada.ca. Retrieved 2020-04-15.
- Media related to Opuntia humifusa at Wikimedia Commons
- Flowering Opuntia humifusa
- Canadian government recovery strategy for Eastern Prickly Pear
- University of Florida - Gardening Solutions - Prickly pear
- Opuntia humifusa images at bioimages.vanderbilt.edu
- Opuntia humifusa photo gallery at Opuntia Web