Pinus strobiformis |
Pinus taeda |
|
---|---|---|
Chihuahua white pine, Mexican white pine, pino enano, Southwestern white pine |
loblolly pine |
|
Habit | Trees to 30m; trunk to 0.9m diam., slender, straight; crown conic, becoming rounded to irregular. | Trees to 46m; trunk to 1.6m diam., usually straight, without adventitious shoots; crown broadly conic to rounded. |
Bark | gray, aging red-brown, furrowed, with narrow, irregular, scaly ridges. |
red-brown, forming square or irregularly rectangular, scaly plates, resin pockets absent. |
Branches | spreading-ascending; twigs slender, pale red-brown, puberulous or glabrous, sometimes glaucous, aging gray or gray-brown, smooth. |
spreading-ascending; twigs moderately slender (to ca. 1cm thick), orangish to yellow-brown, aging darker brown, rough. |
Buds | ellipsoid, red-brown, ca. 1cm, resinous. |
lance-cylindric, pale red-brown, 1–1.2(–2)cm, mostly less than 1cm broad, slightly resinous; scale margins white-fringed, apex acuminate. |
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. |
2–3 per fascicle, ascending to spreading, persisting 3 years, (10–)12–18(–23)cm × 1–2mm, straight, slightly twisted, pliant, deep yellow-green, all surfaces with narrow stomatal lines, margins finely serrulate, apex acute to abruptly conic-subulate; sheath 1–2.5cm, base persistent. |
Pollen cones | cylindric, ca. 6–10mm, pale yellow-brown. |
cylindric, 20–40mm, yellow to yellow-brown. |
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 soon thereafter, not persistent, solitary or in small clusters, nearly terminal, symmetric, lanceoloid before opening, narrowly ovoid when open, 6–12cm, mostly dull yellow-brown, sessile to nearly sessile, scales without dark border on adaxial surface distally; apophyses dull, slightly thickened, variously raised (more so toward cone base), rhombic, strongly transversely keeled; umbo central, recurved, stoutly pyramidal, tapering to stout-based, sharp prickle. |
2n | =24. |
=24. |
Pinus strobiformis |
Pinus taeda |
|
Habitat | Arid to moist summit elevations, montane forests | Mesic lowlands and swamp borders to dry uplands |
Elevation | 1900–3000m (6200–9800ft) | 0–700m (0–2300ft) |
Distribution |
AZ; NM; TX; n Mexico
|
AL; AR; DE; FL; GA; KY; LA; MD; MS; NC; NJ; OK; SC; TN; TX; VA
|
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.) |
Originally most races of Pinus taeda were in the lowlands. Following disturbance of the natural vegetation after settlement by Europeans, the species spread to fine-textured, fallow, upland soils, where it now occurs intermixed with P. echinata and P. virginiana. In the Southeast P. taeda is commonly used in plantation forestry, along with P. elliottii and P. echinata. Pinus taeda frequently forms hybrids with P. echinata and P. palustris (P. × sondereggeri H.H. Chapman). Commercially, it is a valuable pulpwood and timber species. (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 | |
Name authority | Engelmann: in Wislizenus, Mem. Tour N. Mexico 102. (1848) | Linnaeus: Sp. Pl. 2: 1000. (1753) |
Web links |