Plains Prickly-pear Cactus
Opuntia polyacantha Haw.
Family: Cactaceae, Cactus
Genus: Opuntia
Other names: hairspine pricklypear
Nomenclature: polyacantha = with many thorns
Nativity / Invasiveness: Montana native plant
Edible plant
Medicinal plant

General: perennial, forming rounded clumps 10-30 cm tall, often spreading into mats several meters broad. The stem joints obovate to almost round in outline, strongly flattened, mostly 5-15 cm long, not readily detached from the plant, covered with many areoles, often grayish-yellow-woolly, each with tawny spine-like bristles and 5-11 straight spines 1-5 cm long, only slightly barbed, if at all so.

Leaves: none.

Flowers: solitary at branch tips, 5-7 cm broad, borne in areoles of previous years' growth. The many sepals in several series, greenish on the outside, often grading into the numerous broad, yellowish to red or reddish-purple petals. Stamens numerous, in a central cluster, shorter than the petals. Stigma with 5-8 short lobes. May-June.

Fruits: dry berries, pear-shaped, about 2.5 cm long, spine-covered. Seeds strongly flattened, usually disc-shaped.


Dry areas, from the plains into the foothills and lower mountains, in w. and c. parts of MT. Also from B.C. to Alberta, to e. OR, AZ, TX and MO.
Edible Uses

Prickly-pear cactus fruits were widely used for food, either raw or dried for storage. Most of the spines were removed by sweeping piles of fruit with sagebrush branches or by burning the spines off. The spines that remained were picked off with fingers protected by deerskin tips. The fruits were first split to remove the seeds, and then eaten raw or cooked in stews and soups, which they thickened. Raw cactus stems taste like cucumber, but they were usually eaten only when there was a shortage of food. Settlers boiled them to remove the spines, and then fried the pulpy interior. They were also dipped in a syrup made from boiling sweetcorn seeds and then eaten. The seeds can be dried, parched and ground into a meal, then added to flour and used in making cakes etc. When forage was limited, the spines were singed off and cactus stems were fed to livestock.

The plant has numerous minutely barbed glochids (hairs) that are easily dislodged when the plant is touched and they then become stuck to the skin where they are difficult to see and remove. They can cause considerable discomfort.

Medicinal Uses

The stems are urine-inducing and have agents that cause tissue to contract. An infusion has been used in the treatment of diarrhea. A poultice of the flesh has been used to treat skin sores, infections, wounds and back aches.

Other Uses

The peeled stems have been used as a mordant in fixing dyes. A pink to red dye is obtained from the fruit. A gum is obtained from the stem that can be used as an adhesive.

Sub taxa:

Our specimen belong to var. polyacantha Haw.

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