Pinus strobiformis |
Pinus monophylla |
|
---|---|---|
Chihuahua white pine, Mexican white pine, pino enano, Southwestern white pine |
piñón, single leaf pinyon, single-leaf pine, singleleaf pinyon pine |
|
Habit | Trees to 30m; trunk to 0.9m diam., slender, straight; crown conic, becoming rounded to irregular. | Trees to 14m; trunk to 0.5m diam., strongly tapering, much branched; crown usually rounded, dense. |
Bark | gray, aging red-brown, furrowed, with narrow, irregular, scaly ridges. |
red-brown, irregularly furrowed or cross-checked, scaly. |
Branches | spreading-ascending; twigs slender, pale red-brown, puberulous or glabrous, sometimes glaucous, aging gray or gray-brown, smooth. |
spreading and ascending, persistent to near trunk base; twigs stout, orange-brown, aging brown to gray, sometimes sparsely puberulent. |
Buds | ellipsoid, red-brown, ca. 1cm, resinous. |
ellipsoid, light red-brown, 0.5–0.7cm, resinous; scale margins fringed. |
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. |
1(–2) per fascicle, ascending, persisting 4–6(–10) years, 2–6cm × 1.3–2(–2.5)mm, curved, terete (though often 2-grooved), gray-green, all surfaces with stomatal lines, margins entire, apex subulate; sheath 0.5–1cm, scales soon recurved, forming rosette, shed early. |
Pollen cones | cylindric, ca. 6–10mm, pale yellow-brown. |
ellipsoid, ca. 10mm, yellow. |
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, shedding seeds and falling soon thereafter, spreading, symmetric, ovoid before opening, broadly depressed-ovoid to nearly globose when open, 4–6(–8)cm, pale yellow-brown, nearly sessile; apophyses thickened, slightly raised; umbo subcentral, raised or depressed, nearly truncate, apiculate. |
2n | =24. |
=24. |
Pinus strobiformis |
Pinus monophylla |
|
Habitat | Arid to moist summit elevations, montane forests | Dry low-montane or foothill pinyon-juniper woodland |
Elevation | 1900–3000m (6200–9800ft) | 1000–2300m (3300–7500ft) |
Distribution |
AZ; NM; TX; n Mexico
|
AZ; CA; ID; NV; UT; Mexico in Baja California
|
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.) |
Pinus monophylla hybridizes with P. edulis and P. quadrifolia. Singleleaf pinyon (Pinus monophylla) is the state tree of Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 2. | FNA vol. 2. |
Parent taxa | Pinaceae > Pinus | Pinaceae > Pinus |
Sibling taxa | ||
Synonyms | P. ayacahuite var. brachyptera, P. ayacahuite var. reflexa, P. ayacahuite var. strobiformis, P. flexilis var. reflexa, P. reflexa | Caryopitys monophylla, P. californiarum, P. cembroides var. monophylla |
Name authority | Engelmann: in Wislizenus, Mem. Tour N. Mexico 102. (1848) | Torrey & Frémont: in Frémont, Rep. Exped. Rocky Mts. 2: 319, plate 4. (1845) |
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