Common Name: Plains Prickly Pear

General Information

Opuntia polyacantha is a spiny, evergreen succulent shrubby cactus with many branches, forming mats of growth around 10 - 25cm tall and several metres wide[].
The plant is harvested from the wild for local use as a food, medicine and source of materials.
Opuntia polyacantha has a very wide range, is abundant, and there are no threats. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2017)[].

Known Hazards

The plant has numerous minutely barbed glochids - these are barbed spines that are usually small to minute and are very sharp and brittle. The glochids are very easily dislodged when the plant is touched and can penetrate the skin where, because of their barbs, they become stuck and are very difficult to see and remove. They can cause considerable irritation and discomfort[, ].
Opuntia species can contain quite high levels of oxalic acid, especially in older parts of the plant. Perfectly alright in small quantities, foods containing oxalic acid should not be eaten in large amounts since it can lock-up other nutrients in the food, especially calcium, thus causing mineral deficiencies. The oxalic acid content will be reduced if the plant is cooked. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition[, ].

Botanical References

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Range

Central and western N. America - Alberta and Saskatchewan, south to California, Arizona, New Mexico, Texas and northeast Mexico

Habitat

Dry prairies, sand hills and rocks[]. Gravelly rocky soil under dry conditions in creosote bush scrub, pinyon-juniper and joshua tree woodland, chaparral and yellow pine forest at elevations of 300 - 2,800 metres[, ].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	0.15 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Opuntia polyacantha is very tolerant of winter cold and snow, being found as far north as southern Canada. However, it needs hot summers and a faily dry climate in order to thrive, though a wet period of the year can be tolerated[].
Requires a sandy or very well-drained soil[]. Prefers a pH in the range 6 to 7.5[]. Must be kept fairly dry in winter but likes a reasonable supply of water in the growing season[]. A position at the base of a south-facing wall or somewhere that can be protected from winter rain is best for this plant. Requires warmth and plenty of sun. Plants tolerate considerable neglect.

Edible Uses

Fruit - raw, cooked or dried for later use[, , ]. The unripe fruits can be added to soups etc, imparting an okra-like mucilaginous quality[]. The dried fruit can be mixed into stews or used to thicken soups[]. The fruit is dry and spiny[]. The fruits of var erinacea are variously described as sweet and gelatinous[], and lean and insipid[]. The tan to brown, more or less cylindrical fruit is around 15 - 45mm long and 12 - 25mm in diameter, becoming dry at maturity[]. The fruit can hang on the plant all year round[]. Be careful of the plants irritant hairs, see the notes above on toxicity.

Young stem segments are boiled and fried[, ]. The large hairs are burnt off, the segments are boiled and the remaining thorns washed off. The segments are then dipped in a syrup made from boiling sweetcorn seeds and then eaten[].

Seed - dried, parched and ground into a meal, then added to flour and used in making cakes etc[].

Medicinal

The stems are astringent and diuretic[]. An infusion is used in the treatment of diarrhoea[].
A poultice of the flesh has been used to treat skin sores, infections, wounds and back aches[]. The peeled stem segments are applied to wounds as dressings[].

The fuzz of the stems (the irritant glochids?) was rubbed over warts to remove them[].

We have no further specific information on medicinal uses for this species, but the following notes are likely to apply universally to Opuntia species and other related genera[].

The flesh of tender young stem segments can be applied as a poultice to reduce inflammation[].
The mucilage and soluble fibre found in the flowers and stem segments have been shown to help control blood-sugar levels associated with adult-onset diabetes[].
There is clinical evidence that the soluble fibre in the stem segments helps reduce blood cholesterol levels[].

Other Uses

The peeled stems have been used as a mordant in fixing dyes[]. The mucilage in stems has been used as a mordant to stabilize fabric colouring[]. Freshly cut stem segments are rubbed over the dyed pattern to fix the colours[].

A pink to red dye is obtained from the fruit[].

The mucilage in the stems has been used to clarify drinking water[]. Stem segments are split and placed in a container with the water, with the exuded sticky juice quickly clearing the water[]

A gum is obtained from the stem that can be used as an adhesive[].

Propagation

Seed - sow early spring in a very well-drained compost in a greenhouse. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first two winters. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Give the plants some protection from winter wet. Make sure you have some reserve plants in case those outdoors do not overwinter.
Cuttings of leaf pads at any time in the growing season. Remove a pad from the plant and then leave it in a dry sunny place for a couple of days to ensure that the base is thoroughly dry and has begun to callous. Pot up into a sandy compost. Very easy, rooting quickly.