Pinus strobiformis

Engelmann in Wislizenus
in Wislizenus,Mem. Tour N. Mexico 102. 1848.
Common names: Southwestern white pine Mexican white pine pino enano
Synonyms: Pinus ayacahuite var. brachyptera G.R. Shaw Pinus ayacahuite var. reflexa (Engelmann) Voss Pinus ayacahuite var. strobiformis (Engelmann) Lemmon Pinus flexilis var. reflexa Engelmann Pinus reflexa
Treatment appears in FNA Volume 2.

Trees to 30m; trunk to 0.9m diam., slender, straight; crown conic, becoming rounded to irregular. Bark gray, aging red-brown, furrowed, with narrow, irregular, scaly ridges. Branches spreading-ascending; twigs slender, pale red-brown, puberulous or glabrous, sometimes glaucous, aging gray or gray-brown, smooth. Buds ellipsoid, red-brown, ca. 1cm, resinous. 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. Pollen cones cylindric, ca. 6–10mm, pale yellow-brown. Seed 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. Seeds ovoid; body 10–13mm, red-brown, essentially wingless. 2n =24.


Habitat: Arid to moist summit elevations, montane forests
Elevation: 1900–3000m

Distribution

V2 186-distribution-map.gif

Ariz., N.Mex., Tex., n Mexico.

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.

Selected References

None.

Lower Taxa

None.

... more about "Pinus strobiformis"
Robert Kral +
Engelmann in Wislizenus +
Southwestern white pine +, Mexican white pine +  and pino enano +
Ariz. +, N.Mex. +, Tex. +  and n Mexico. +
1900–3000m +
Arid to moist summit elevations, montane forests +
in Wislizenus,Mem. Tour N. Mexico +
Pinus ayacahuite var. brachyptera +, Pinus ayacahuite var. reflexa +, Pinus ayacahuite var. strobiformis +, Pinus flexilis var. reflexa +  and Pinus reflexa +
Pinus strobiformis +
species +