Pinus strobiformis |
Pinus elliottii |
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Chihuahua white pine, Mexican white pine, pino enano, Southwestern white pine |
slash pine |
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Habit | Trees to 30m; trunk to 0.9m diam., slender, straight; crown conic, becoming rounded to irregular. | Trees to 30m; trunk to 0.8m diam., straight to contorted; crown conic, becoming rounded or flattened. | ||||
Bark | gray, aging red-brown, furrowed, with narrow, irregular, scaly ridges. |
orange- to purple-brown, irregularly furrowed and cross-checked into large, irregularly rectangular, papery-scaly plates. |
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Branches | spreading-ascending; twigs slender, pale red-brown, puberulous or glabrous, sometimes glaucous, aging gray or gray-brown, smooth. |
spreading to ascending; twigs stout (to ca. 1cm thick), orange-brown, aging darker brown, rough-scaly. |
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Buds | ellipsoid, red-brown, ca. 1cm, resinous. |
cylindric, silvery brown, 1.5–2cm; scale margins fringed. |
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Leaves | 5 per fascicle, spreading to ascending-upcurved, persisting 3–5 years, 4–9cm × 0.6–1mm, straight, slightly twisted, pliant, dark green to blue-green, abaxial surface without evident stomatal lines, adaxial surfaces conspicuously whitened by narrow stomatal lines, margins sharp, razorlike and entire to finely serrulate, apex narrowly acute to short-subulate; sheath 1.5–2cm, shed early. |
2 or 3 per fascicle, spreading or ascending, persisting ca. 2 years, 15–20(–23)cm × 1.2–1.5mm, straight, slightly twisted, pliant, yellow- to blue-green, all surfaces with stomatal lines, margins finely serrulate, apex abruptly acute to acuminate; sheath 1–2cm, base persistent. |
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Pollen cones | cylindric, ca. 6–10mm, pale yellow-brown. |
cylindric, 30–40mm, purplish. |
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Seed(s) | cones maturing in 2 years, shedding seeds and falling soon thereafter, pendent, symmetric, lance-cylindric before opening, broadly lance-cylindric when open, 15–25cm, creamy brown to light yellow-brown, stalks to 6cm; apophyses somewhat thickened, strongly cross-keeled, tip reflexed; umbo terminal, low. |
cones maturing in 2 years, falling the year after seed-shed, single or in pairs, symmetric, lance-ovoid before opening, ovoid or ovoid-cylindric when open, (7–)9–18(–20)cm, light chocolate brown, on stalks to 3cm; apophyses lustrous (as if varnished), slightly raised, strongly cross-keeled; umbo central, depressed-pyramidal, with short, stout prickle. |
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2n | =24. |
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Pinus strobiformis |
Pinus elliottii |
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Habitat | Arid to moist summit elevations, montane forests | |||||
Elevation | 1900–3000m (6200–9800ft) | |||||
Distribution |
AZ; NM; TX; n Mexico
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AL; FL; GA; LA; MS; SC [Introduced in subtropical and warm temperate areas worldwide]
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Discussion | In the northern part of the range, Pinus strobiformis overlaps P. flexilis and reportedly hybridizes with it. On average P. strobiformis has longer, more slender leaves and thinner, more spreading-tipped apophyses than are found in P. flexilis, and stomatal bands are not evident on the abaxial surface of its leaves. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (native only in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 2. | FNA vol. 2. | ||||
Parent taxa | Pinaceae > Pinus | Pinaceae > Pinus | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | P. ayacahuite var. brachyptera, P. ayacahuite var. reflexa, P. ayacahuite var. strobiformis, P. flexilis var. reflexa, P. reflexa | P. heterophylla, P. taeda var. heterophylla | ||||
Name authority | Engelmann: in Wislizenus, Mem. Tour N. Mexico 102. (1848) | Engelmann: Trans. Acad. Sci. St. Louis 4: 186, plates 1–3. (1880) | ||||
Web links |