Opuntia cespitosa, Common Eastern Pricklypear

Opuntia cespitosa
Opuntia cespitosa

See O. humifusa    See O. lata    See O. mesacantha

Rafinesque, Bulletin Botanique 2: 216, 1830

Neotype; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Original Description; Drawing (Britton and Rose v1, 1919)

What is Opuntia cespitosa?

Opuntia cespitosa is a widespread eastern North American prickly-pear forming low, cespitose clumps that stay firm in season and often cross-wrinkle in colder months. Typical plants bear bright yellow flowers with a reddish to maroon basal flare and green stigma lobes; fruits are commonly clavate to oblong. Seeds show a distinctly rough, bumpy funicular envelope. In combination—habit, armament, fruit form, and seed texture—these characters separate it from other members of the O. humifusa complex.

Details

Shrubs: low, compact, and clump-forming; chains of pads often radiate close to the ground surface; plants remain turgid through the growing season and typically cross-wrinkle in winter. Cladodes: obovate to rotund, moderately thick, dull green to slightly glaucous; margins usually even. Areoles: moderately spaced, bearing tan to yellow glochids, especially on upper pads. Spines: 0–2 (to 3) per areole on upper pads; spines pale, slender, straight to slightly curved; bases round to only slightly flattened; lacking the strongly retrorsely-barbed spines typical of O. mesacantha. Flowers: bright yellow with a distinct red to maroon basal flare; stamens thigmonastic; stigma lobes greenish. Fruits: clavate to cylindric, maturing red-purple. Seeds: with a rough, bumpy funicular envelope—useful diagnostically within the complex.

Cytology

Known: tetraploid (2n = 44), within the Humifusa clade.

Range & Habitat

Occurs across much of the eastern and central United States—from the Great Lakes and Northeast (e.g., MI, ON at Point Pelee, NY, CT, MA) south and west through the Ohio and Tennessee valleys into the Mid-South and lower Midwest (e.g., AL, GA, IL, IN, MO, MS, OH, VA, WV). It favors sunny, well-drained sites: rocky or thin soils over limestone or sandstone, sandy prairies, glades, barrens, dunes, and open banks.

Similar or Sympatric Species

O. humifusa — Pads often thinner and frequently spineless; flowers usually all-yellow; seeds less roughened.

O. mesacantha — More coastal-plain in emphasis; commonly with retrorsely-barbed spines; flowers typically all-yellow; seed envelope less bumpy.

O. macrorhiza — Generally western/Great Plains; plants more erect; fruits often barrel-shaped rather than clavate; spines more numerous and spreading.

O. nemoralis — South-central; can overlap regionally; pads thinner, often fewer spines; differing seed and fruit details.

Other Notes

The original spelling “cespitosa” (not “caespitosa”) follows Rafinesque (1830). Live-plant evaluation across seasons—especially noting armament, fruit shape, and seed texture—helps separate this taxon from superficially similar eastern forms.

For more information, see:

Majure: Typifications and a nomenclatural change in some eastern North American Opuntia

Cytogeography of the Humifusa clade of Opuntia

The Opuntia (Cactaceae) of Mississippi

Morphological and Ecological Characterization of Opuntia on the South Carolina coast

Flora of the Southern and Mid-Atlantic States

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6 thoughts on “Opuntia cespitosa, Common Eastern Pricklypear”

  1. David A Schaeffer

    There are cliffs overlooking the Delaware River just N of Milford, NJ, with a large population of what I always assumed to be O. humifusa. However, these plants occasionally exhibit spines. Thoughts?

  2. Bill Harms

    If it has spines and the base of the tepals are red or orange, or if they have a reddish/orangish tint, it is possible they are O cespitosa.

  3. Joseph

    Hi Botany Bill,
    Thanks for visiting our website.

    Your description sounds like O. cespitosa to me if it is east of the Mississippi River.
    West of the river (somewhere) O. macrorhiza begins. The two are very similar and a colleague calls them all O. macrorhiza, east or wet.
    The red in the center of the flower is very telling. Much depends on the size of the plant, large woody plants would not be O. macrorhiza or O. cespitosa.

    Joe Shaw

  5. Derek Stephen Hollingshead

    “Is the only Opuntia that occurs in eastern Canada (far southern Ontario).”

    Hey Joe!

    I think this anecdote can be revised for both the Kaladar, ON O. fragilis and Thousand Islands, ON O. polyacantha populations.

    Hope you are doing well :)

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