| Opuntia polyacantha | |
|---|---|
 | |
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Cactaceae |
| Genus: | Opuntia |
| Species: | O. polyacantha |
| Binomial name | |
| Opuntia polyacantha | |
%2c_Range_Map.svg) | |
| Opuntia polyacantha range map, estimated with theiNaturalist Geomodel, 2025 | |
Opuntia polyacantha is a common species ofcactus known by the common namesplains pricklypear,[3][4]starvation pricklypear,[5]hairspine cactus,[3] andpanhandle pricklypear.[2]
Opuntia polyacantha grows up to 10–30 centimetres (4–12 in) tall. It forms low mats of pads which may be 2–3 m (6+1⁄2–9+7⁄8 ft) wide.[3] Its succulent green pads are oval or circular and reach27 by 18 cm (10+5⁄8 by7+1⁄8 in) wide. Itsareoles are tipped with woolly brown fibers andglochids. Many of the areoles havespines which are quite variable in size and shape. They may be0.4 to 18.5 cm (1⁄8 to7+1⁄4 in) in length, stout or thin, straight or curling, and any of a variety of colors.
Flowers grow from spine-covered stem segments which are shaped like semi-flattened pears.[6] The flowers are2.5 to 4 cm (1 to1+5⁄8 in) long and may be yellow, magenta,[5] or red in color (tending to turn pink or orange with age).[6] The fruit is cylindrical, brownish, dry and spiny.[5] The cactus reproduces by seed, bylayering, and by re-sprouting from detached segments.[3] In its natural range it survives throughout an immense range of temperatures, ranging from −46 °C (−50 °F) in theYukon Territory, Canada,[7] to well above 38 °C (100 °F) in places likeChihuahua, Mexico.
It is native to North America, where it is widespread inWestern Canada, theGreat Plains, the central andWestern United States, andChihuahua in northern Mexico.[2][5] In 2018, a disjunct population was discovered in theThousand Islands region ofOntario, Canada.[8][9][1] This cactus grows in a wide variety of habitat types, includingsagebrush,Ponderosa pine forest,prairie, savanna, shrublands,shrubsteppe,chaparral,pinyon-juniper woodland, andscrub.[3] Individual plants tend to thrive in sandy soil. A new plant can grow from a displaced stem segment.[6]
Native Americans used it as amedicinal plant, with different parts treating various symptoms.[10]
This pricklypear provides food for many types of animals. It provides over half the winter food for theblack-tailed prairie dog in one area.Pronghorn antelope eat it, especially after the spines are burned off inwildfires. Ranchers intentionally burn stands of the plant to make it palatable for livestock when little other food is available. It will also grow in waste areas where good forage will not take hold. In fact, an abundance of the cactus indicates land that is poor in quality.[3]
Several insects attack the cactus, including the cactus mothMelitara dentata, the blue cactus borerOlycella subumbrella, and the cactus bugChelinidea vittiger.[3]
O. polyacantha provided theLewis and Clark Expedition with opportunity for admiration and more often complaint about the plant.[11]
With the skin and seeds removed, the fruit can be eaten raw or made into candy.[12]
There are many expressions ofO. polyacantha and variation is common. Multiple varieties have been proposed. Some are accepted by modern authorities and some require further study. An incomplete list of proposed varieties includes:[13][14]
