Opuntia fragilis

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Opuntia fragilis
Opuntia fragilis 1.jpg
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Core eudicots
Order: Caryophyllales
Family: Cactaceae
Genus: Opuntia
Species: O. fragilis
Binomial name
Opuntia fragilis
(Nutt.) Haw.
Synonyms

Cactus fragilis
Opuntia brachyarthra

Opuntia fragilis, known by the common names brittle pricklypear and little prickly pear, is a prickly pear cactus native to much of western North America as well as some eastern states such as Illinois, Iowa, Wisconsin and Michigan. It occurs in several Canadian provinces. It is known from farther north than any other cactus,[1] occurring at as close as 8°south of the Arctic Circle, (58°N latitude) in Alberta.[2] There is an isolated and possibly genetically unique population in Eastern Ontario known as the "Kaladar cactus".[3]

Description[edit]

Brittle pricklypear is a small decumbent cactus that grows to a maximum height of 10 centimeters (4 in).[4] Both the common and scientific names refer to the easily detached stem segments. This is known to be a means of plant dispersal.[4]

Opuntia fragilis is a small, prostrate plant, rarely more than 4 inches high: joints tumid, fragile, easily detached, oval, elliptical, or subglobose, 1-2 in. long and nearly as thick as broad, bright green: areoles ¼-½ in. apart, with whitish wool and a few white to yellow bristles, which are much longer and more abundant on older joints; spines 1-4, occasionally a few small additional ones, weak, dark brown, the upper one usually longer and stronger than the others, rarely an inch in length: flowers greenish yellow, 1-1¼ inches wide: fruit ovate to subglobose. with few spines or bristles, mostly sterile, an inch or less long; seeds few and large. Rocky Mountain region from Canada to New Mexico.[5]

Subspecies and varieties[edit]

  • Var. brachyarthra, Coult. A plant with more swollen joints, more numerous and stronger spines, smaller flowers and more spiny fruit Colorado, New Mexico.
  • Var. caespitosa, Hort. Joints bright green, smaller and more crowded than in the type: flowers bright yellow. Colorado.
  • Var. tuberiformis, Hort. Joints olive-green, bulbous-looking. Colorado.

References[edit]

  1. ^ C.Michael Hogan. 2011. Cactus. Topic ed. Arthur Dawson. Ed.-in-chief Cutler J.Cleveland. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC
  2. ^ US Forest Service
  3. ^ http://www3.sympatico.ca/lycacti/kaladar.html
  4. ^ a b 32. Opuntia fragilis (Nuttall) Haworth, Flora of North America
  5. ^ Haw.

External links[edit]