Cylindropuntia acanthocarpa |
Cylindropuntia davisii |
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buck-horn cholla |
Davis cholla, thistle cholla |
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Habit | Trees or shrubs, sparsely to densely branched, 1–2(–4) m. Stem segments firmly attached, cylindric, 10–30(–50) × 2–2.5(–3) cm; tubercles prominent, narrow to broad, 1.5–4.5 cm; areoles elliptic to subcircular, 4–5.5 × 4–5 mm; wool white or yellowish to tan, aging gray-black. | Shrubs, densely branched, 0.2–0.6 m; roots with elongate, tuberlike swellings. | ||||||||||||
Stem | segments easily detached, whorled, obscuring trunks, light green, 4–6 × 0.8–1.2 cm; tubercles prominent, 1–2 cm; areoles subcircular, 2–3.5 mm in diam.; wool tan. |
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Spines | 6–20(–30+) per areole, often accompanied by 0–5 short bristlelike spines at areole margins, usually in distal areoles; major abaxial spines deflexed to divergent, subterete to flattened; major adaxial spines ascending-divergent, terete, yellow or tan to deep red-brown, aging gray, the central spine longest, 12–30(–38) mm; sheaths white to grayish with yellow to golden tips, baggy to tight fitting. |
7–13(–21) per areole, at most areoles, spreading, obscuring stems, yellow- to red-brown to nearly black, tipped yellow, subterete to angularly flattened, the longest 1.5–5 cm; sheaths loose fitting, ± yellow to tan, 1.5–2 mm diam. |
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Glochids | in inconspicuous to small adaxial tuft, yellow to brown, 0.5–2 mm. |
in adaxial tuft, yellow, 2–4 mm. |
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Flowers | inner tepals bright yellow to bronze to brick red, spatulate, 20–30 mm, apiculate-emarginate; filaments red; anthers yellow; style and stigma lobes white to light green. |
inner tepals yellow-green, tinged purple-red, aging reddish brown or bronze, spatulate, 15 mm, apiculate; filaments pale green basally to purplish distally; anthers orange-yellow; style cream to pale green, sometimes faint purple-pink distally; stigma lobes very pale green. |
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Fruits | tan at maturity, obconic to ellipsoid, 15–35 × 15–20 mm, dry, tuberculate, densely to sparsely spiny (rarely spineless), with apical flange above shallow umbilicus; basal tubercles longest; areoles 12–30. |
usually sterile, often in chains of 2, yellow, top-shaped, 20–30 × 10–20 mm, pulpy, tuberculate, spineless (rarely few-spined); tubercles subequal; umbilicus 5–8 mm deep; areoles 20–35. |
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Seeds | pale yellow to tan, angular or squarish in outline, warped, 3.5–5 × 3–4.5 mm, sides smooth, each with 2–4 large depressions; girdle smooth. |
, when present, yellow-tan, subcircular, flattened, 3 mm diam., sides smooth; girdle narrow, not protruding. |
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2n | = 22, 44 (one count). |
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Cylindropuntia acanthocarpa |
Cylindropuntia davisii |
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Phenology | Flowering late spring (May–Jun). | |||||||||||||
Habitat | Grasslands, oak-juniper-mesquite woodlands, plains or slopes, sandy to loamy soils | |||||||||||||
Elevation | 600-1500 m (2000-4900 ft) | |||||||||||||
Distribution |
AZ; CA; NV; UT; n Mexico
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NM; OK; TX |
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Discussion | Varieties 4 (4 in the flora). Cylindropuntia acanthocarpa hybridizes with C. abyssi, C. echinocarpa (= C. ×deserta), C. bigelovii (= C. ×campii), C. leptocaulis (see C. ×tetracantha), C. ×multigeniculata, C. spinosior, C. versicolor, and C. whipplei (= C. congesta). Hybrids of C. acanthocarpa and C. ×multigeniculata are more open in habit, with longer stem segments than C. ×multigeniculata and with reddish filaments like C. acanthocarpa. (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, p. 111. | ||||||||||||
Parent taxa | Cactaceae > subfam. Opuntioideae > Cylindropuntia | Cactaceae > subfam. Opuntioideae > Cylindropuntia | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate taxa | ||||||||||||||
Synonyms | Opuntia acanthocarpa | Opuntia davisii, Opuntia tunicata var. davisii | ||||||||||||
Name authority | (Engelmann & J. M. Bigelow) F. M. Knuth: in C. Backeberg and F. M. Knuth, Kaktus-ABC, 124. (1935) | (Engelmann & J. M. Bigelow) F. M. Knuth: in C. Backeberg and F. M. Knuth, Kaktus-ABC, 124. (1935) | ||||||||||||
Web links |