1. Guides
  2. Cactus of Metro Phoenix (April 2021 EcoQuest Guide)
  3. purple prickly pear

purple prickly pear

Opuntia macrocentra

Summary 10

Opuntia macrocentra, the long-spined purplish prickly pear or purple pricklypear, is a cactus found in the lower Southwestern United States and Northwestern Mexico. A member of the prickly pear genus, this species of Opuntia is most notable as one of a few cacti that produce a purple pigmentation in the stem. Other common names for this plant include black-spined pricklypear, long-spine prickly pear, purple pricklypear, and redeye prickly pear.

Description 11

Opuntia macrocentra is an upright spreading shrub, usually growing from 30–60 centimetres (1–2 ft) tall. Individuals occasionally reach 1 metre (1 yard) in height. The stem is blue-gray, blue-green, or purplish in color. The purple pad color is the most intense at the edges of the pad or around the areoles. The purple color comes from the production of a betalain (betacyanin) pigment that becomes more evident as the plant is stressed by drought or cold.

The cactus consists of smooth obovate to orbicular shaped pads that are connected to each other by the bottom edge or pad margin. Each pad is from 10–20 centimetres (4–8 in) in width and 10–20 centimetres (4–8 in) in length, but is usually wider than it is long. The areoles, highly reduced branch structures from which spines and glochids grow, are dark in color and can be found arranged in diagonal rows on the midstem segment.

Spines are produced on the upper half or the upper edge only of the pad. Each aerole will have from 1-3 central spines coming from it with the longest being 5–10 centimetres (2–4 in) in length. The largest spine will be pointed in a markedly upward direction. Spines are sometimes seen with a white or yellow tip. Flowers are produced on the upper edge of the pads.

Flowers of Opuntia macrocentra are large sturdy flowers of bright colors. They consist of yellow petals with red lower portions forming a bright red center. The visible internal reproductive structures are pale yellow to cream in color. This cactus produces flowers in spring, usually March through June. The flowers open in the midmorning, close at night and do not reopen.

If the flower is pollinated, the cactus will produce small oval shaped fruits ranging in color from bright red to dull purple when ripe.
The fruit produced is succulent and approximately half the size of the flower, from 2.5 to 4.0 centimetres (1 to 1 5⁄8 in) in length. Each fruit has between 12-16 areoles. The rind of the fruit is purple and the inner pulp and juices are light purple to clear in color. The fruit contains flattened, tan seeds that are less than approximately 4 millimetres (5⁄32 in) in length with a broad notch on one side and prominent ridge.

Distribution 11

Native populations of Opuntia macrocentra are found in Arizona, New Mexico, Southwestern Texas, and Northwestern Mexico.

This cacti is a slow growing perennial that inhabits a wide range of soil substrates and habitat types. It can be found below the elevation of 5000 ft in areas of sandy desert flats, rocky hills, or valley grasslands.

Flowers 11

Flowers of Opuntia macrocentra are large sturdy flowers of bright colors. They consist of yellow petals with red lower portions forming a bright red center. The visible internal reproductive structures are pale yellow to cream in color. This cactus produces flowers in spring, usually March through June. The flowers open in the midmorning, close at night and do not reopen.

Fruit 11

If the flower is pollinated, the cactus will produce small oval shaped fruits ranging in color from bright red to dull purple when ripe.
The fruit produced is succulent and approximately half the size of the flower, from 2.5 to 4.0 centimetres (1 to 1 5⁄8 in) in length. Each fruit has between 12-16 areoles. The rind of the fruit is purple and the inner pulp and juices are light purple to clear in color. The fruit contains flattened, tan seeds that are less than approximately 4 millimetres (5⁄32 in) in length with a broad notch on one side and prominent ridge.

Pads 11

The cactus consists of smooth obovate to orbicular shaped pads that are connected to each other by the bottom edge or pad margin. Each pad is from 10–20 centimetres (4–8 in) in width and 10–20 centimetres (4–8 in) in length, but is usually wider than it is long. The areoles, highly reduced branch structures from which spines and glochids grow, are dark in color and can be found arranged in diagonal rows on the midstem segment.

Spines are produced on the upper half or the upper edge only of the pad. Each aerole will have from 1-3 central spines coming from it with the longest being 5–10 centimetres (2–4 in) in length. The largest spine will be pointed in a markedly upward direction. Spines are sometimes seen with a white or yellow tip. Flowers are produced on the upper edge of the pads.

Uses 11

Because of its striking stem and flower color the Opuntia macrocentra cactus is cultivated as an ornamental plant for drought tolerant and native plant gardens, and as a potted plant.

Like many other cacti in the genus Opuntia, the fruit produced by Opuntia macrocentra is edible.

Collection of this cactus, and its fruit, is restricted in some areas for conservation needs.

Sources and Credits

  1. (c) Ad Konings, some rights reserved (CC BY-NC), uploaded by Ad Konings
  2. (c) The Ruth Bancroft Garden, some rights reserved (CC BY-NC), https://www.flickr.com/photos/ruthbancroftgarden/1822021448/
  3. (c) Gary Nored, some rights reserved (CC BY-NC), https://www.flickr.com/photos/aneyefortexas/3554322450/
  4. (c) William Herron, some rights reserved (CC BY-SA), https://www.flickr.com/photos/wdherron/26303358922/
  5. (c) Eric Barbier, some rights reserved (CC BY-NC-SA), https://www.flickr.com/photos/115942345@N06/37436772400/
  6. (c) Matt Baker, some rights reserved (CC BY-NC-ND), https://www.flickr.com/photos/mattybravo/47578608792/
  7. (c) Jerry Oldenettel, some rights reserved (CC BY-NC-SA), https://www.flickr.com/photos/jroldenettel/27811251898/
  8. (c) CK Kelly, some rights reserved (CC BY), uploaded by CK Kelly
  9. (c) Adrienne McLeod, some rights reserved (CC BY-NC), uploaded by Adrienne McLeod
  10. Adapted by Jeny Davis from a work by (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Opuntia_macrocentra
  11. (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Opuntia_macrocentra

More Info

iNat Map

Member of the iNaturalist Network   |   Powered by iNaturalist open source software |   Documentation for developers