Opuntia polyacantha |
Opuntia rufida |
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hair-spine prickly pear, panhandle prickly pear, plains prickly pear, starvation prickly-pear |
blind prickly pear, nopal rojizo |
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Habit | Shrubs, low, 10–25 cm, with ± prostrate branches. | Shrubs or trees, with short trunk, many branched, 0.5–1.5 m. Stem segments not disarticulating, grayish green, flattened, reniform, circular, elliptic, or obovate, (7.5–)10–18(–25) × 5–25 cm, low tuberculate, pubescent; areoles 8–13 per diagonal row across midstem segment, circular, 3–3.2 mm diam.; wool white to tan, aging gray. | ||||||||||||||||
Stem | segments not easily detached, green, elliptic to narrowly to broadly obovate to circular, 4–27 × 2–18 cm, low tuberculate; areoles 4–14 per diagonal row across midstem segment, subcircular, 3–6 mm; wool tan to brown. |
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Spines | at all or only distal areoles of stem segment, terete to flattened, stout to acicular to bristlelike, straight to curling, of 1 or 2 kinds; if 1 kind: 0–18 per areole, spreading and curling in various directions, sometimes straight, erect, ascending to deflexed, yellow to dark brown to black, turning gray, pink-gray to gray-brown, longest (35–)40–90(–185) mm; if ± 2 kinds: major spines (0–)1–5, reflexed to porrect, yellow-brown to brown to gray, longest 20–150 mm; minor spines (0–)5–11, deflexed, white to white-gray, longest 4–16 mm. |
absent. |
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Glochids | inconspicuous, in narrow, tidy crescent at adaxial edge of areole or in broad, brushy crescent and tuft, yellow to reddish, aging brown, to 10 mm. |
numerous, nearly filling areole, red-brown to white, 1–2.5 mm. |
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Flowers | inner tepals yellow to magenta throughout, 25–40 mm; filaments white, yellow, or red to magenta (flowers may superficially appear bicolored); anthers yellow; style white to pale pink; stigma lobes green. |
inner tepals yellow throughout, aging apricot to orange, obovate-apiculate, 25–38 mm; filaments whitish; anthers yellow; style green; stigma lobes dark green. |
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Fruits | tan to brown, ± cylindric, 15–45 × 12–25 mm, dry at maturity, glabrous, sometimes burlike; areoles 10–33, each or only distal areoles bearing 3–16 spines, 4–20 mm. |
red with green flesh, obovate, 20–35 × 15–23 mm, fleshy, short pubescent, spineless; umbilicus 5–7 mm deep; areoles (30–)36–52. |
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Seeds | tan to gray, flattened, warped, oblong to subcircular, 3–7 × 2–4 mm; girdle protruding 1–2 mm. |
yellowish, elliptic to subcircular, angular, 3–3.5 × 2.5–2.8 mm, thick, sides smooth or with 1–2 depressions; girdle protruding about 0.3 mm. |
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2n | = 22. |
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Opuntia polyacantha |
Opuntia rufida |
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Phenology | Flowering spring (Mar–Apr). | |||||||||||||||||
Habitat | Calcareous to volcanic flats, hillsides, sandy to gravelly desert soils | |||||||||||||||||
Elevation | 600-1300 m (2000-4300 ft) | |||||||||||||||||
Distribution |
AZ; CA; CO; ID; KS; MT; ND; NE; NM; NV; OK; SD; TX; UT; WY; AB; SK; n Mexico
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TX; Mexico (Chihuahua, Coahuila, Durango)
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Discussion | Varieties 5 (5 in the flora). Populations of Opuntia polyacantha with spines few or absent (especially var. hystricina) were the basis for several names including O. juniperina, O. utahensis, and O. rhodantha. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Opuntia rufida hybridizes in Mexico with O. microdasys. The vernacular name is derived from the tendency for the glochids to shed into the eyes of grazing cattle that bump against the plant. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 4. | FNA vol. 4. | ||||||||||||||||
Parent taxa | Cactaceae > subfam. Opuntioideae > Opuntia | Cactaceae > subfam. Opuntioideae > Opuntia | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | Cactus ferox, Tunas polyacantha | O. microdasys var. rufida, O. rufida var. tortiflora | ||||||||||||||||
Name authority | Haworth: Suppl. Pl. Succ., 82. (1819) | Engelmann: Proc. Amer. Acad. Arts 3: 298. (1856) | ||||||||||||||||
Web links |
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