|Eastern prickly pear|
This species ranges from the more arid areas of Montana southward to New Mexico scrub lands, then eastward to the lower Great Lakes, eastward to dry coastal and sand dune environments along the Eastern seaboard from the Florida Keys to coastal Connecticut and Long Island, NY. 
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 across. This cactus blooms in the late spring.
The juicy and edible red fruits measure from 3–5 cm. 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.
This plant is very intolerant of shade. It thrives in full sun in hot and dry environments and needs well-drained soil. Opuntia humifusa will grow in open or exposed areas in rocky and coastal scrub habits as well as at elevations where winter hardy.
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.
Close-up of yellow barbed bristles and longer spines
- Speciesatrisk.gc.ca entry for Eastern Prickly Pear
- Florida's Forest Plants - Prickly pear
- Opuntia humifusa images at bioimages.vanderbilt.edu