Opuntia macrorhiza Engelm.
  • Boston J. Nat. Hist.
  • Western pricklypear


Cite taxon page as 'WFO (2020): Opuntia macrorhiza Engelm. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-0001287376. Accessed on: 30 May 2020'

General Information

Shrubs, forming clumps, 7.5-16 cm, sometimes from tuberlike rootstocks. Stem segments not easily detached, dark dull green, often cross wrinkled when stressed, flattened, obovate to circular, 5-11 × 3.5-7.5 cm, fleshy (to flabby and cross wrinkled when stressed), tuberculate, glaucous; areoles 5-6(-8) per diagonal row across midstem segment, oval to subcircular, 2-4 mm diam.; wool tan. Spines (0-)1-4 per areole, usually in distal areoles, erect to spreading, white to red-brown, acicular, straight, terete or 1 flattened, ± stout (0.5 mm diam. at base), longest to 60 mm. Glochids in dense tuft, pale yellow, tan to red-brown, aging brown, to 5 mm. Flowers: inner tepals yellow with red basal portions, 25-40 mm; filaments pale yellow; anthers yellow; style white; stigma lobes cream to yellowish. Fruits green to yellowish to dull red, stipitate, elongate-obovoid, 25-40 × 15-28 mm, fleshy, glabrous; areoles 16-28. Seeds tan, subcircular, 4-5 mm, thickish, warped; girdle broad, protruding to 0.5 mm. 2n = 44.

  • Provided by: [C].Flora of North America @ efloras.org
    • Source: [
    • 1
    • ]. 

    "Prostrate and spreading, forming mats to 1.5 m wide; usually some roots tuberous-thickened; joints of the stem mostly 6–10 × 5–7 cm, flat, orbicular to obovate; areoles on full-grown joints 15–30 mm apart, with (1–)3–6 spines 3.5–5.5 cm; fls yellow with reddish center, 5–7 cm wide; outer sep ovate, acute to acuminate; fr reddish-purple, 2.5–4 cm, juicy; seeds discoid with a rough, irregular, corky margin. Prairies and plains; S.D. to Ariz. and Tex., e. occasionally to Wis., s. Mich., Ill., and reputedly O. and Ky. May–July. (O. mesacantha; O. tortispina, misapplied) O. polyacantha Haw., a similar western sp. with 6–10 spines per areole and dry frs, has been reported e. to Wis. and Mo."

  • Provided by: [B].New York Botanical Garden
    • Source: [
    • 2
    • ]. 

    Other Local Names

    NameLanguageCountry
    Western pricklypear

      Bibliography

     Information From

    Cactaceae
    World Flora Online Data. 2017.
    • A CC0 1.0 Universal (CC0 1.0).
    New York Botanical Garden
    Descriptions of plants should be attributed to the full citation for each individual article, chapter or book that is the source for each record, which should include the authors of original publication.
    • B Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
    Flora of North America @ efloras.org
    http://www.efloras.org/flora_page.aspx?flora_id=1
    'Flora of North America @ eFloras (2008). Published on the Internet http://www.efloras.org/flora_page.aspx?flora_id=1 [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • C Flora of North America Association
    World Flora Online consortium
    http://www.worldfloraonline.org/organisation/WFO
    World Flora Online Data. 2018.
    • D CC0 1.0 Universal (CC0 1.0).
    International Union for Conservation of Nature v.3
    https://www.iucnredlist.org/
    IUCN 2019. The IUCN Red List of Threatened Species. Version 2019-1.
    • E See IUCN Terms and conditions of use http://www.iucnredlist.org/info/terms-of-use
    International Union for Conservation of Nature
    https://www.iucn.org/
    IUCN 2016. IUCN Red List of Threatened Species. Version 2016-2
    • F All Rights Reserved