Pinus balfouriana

Greville & Balfour in A. Murray bis

in A. Murray bis,Bot. Exped. Oregon 8: no. 618, plate 3, fig. 1. 1853.

Common names: Foxtail pine
Synonyms: Pinus balfouriana var. austrina (R.Mastrogiuseppe & J.Mastrogiuseppe) Silba Pinus balfouriana subsp. austrina R.Mastrogiuseppe & J.Mastrogiuseppe
Treatment appears in FNA Volume 2.
Revision as of 20:53, 16 December 2019 by FNA>Volume Importer

Trees to 22m; trunk to 2.6m diam., erect or leaning; crown broadly conic to irregular. Bark gray to salmon or cinnamon, platy or irregularly deep-fissured or with irregular blocky plates. Branches contorted, ascending to descending; twigs red-brown, aging gray to drab yellow-gray, glabrous or puberulent, young branches resembling long bottlebrushes because of persistent leaves. Buds ovoid-acuminate, red-brown, 0.8–1cm, resinous. Leaves 5 per fascicle, upcurved, persisting 10–30 years, 1.5–4cm × 1–1.4mm, mostly connivent, deep blue- to deep yellow-green, abaxial surface without median groove but usually with 2 subepidermal but evident resin bands, adaxial surfaces conspicuously whitened by stomates, margins mostly entire to blunt, apex broadly acute to acuminate; sheath 0.5–1cm, soon forming rosette, shed early. Pollen cones ellipsoid, ca. 6–10mm, red. Seed cones maturing in 2 years, shedding seeds and falling soon thereafter, spreading, symmetric, lance-cylindric with conic base before opening, broadly lance-ovoid or ovoid to cylindric or ovoid-cylindric when open, 6–9(–11)cm, purple, aging red-brown, nearly sessile; apophyses much thickened, rounded, larger toward cone base; umbo central, usually depressed; prickle absent or weak, to 1mm, resin exudates amber. Seeds ellipsoid to narrowly obovoid; body to 10mm, pale brown, mottled with deep red; wing 10–12mm. 2n =24.


Habitat: Timberline and alpine meadows
Elevation: 1500–3500m

Discussion

Pinus balfouriana is the true "foxtail pine." In leaf character it is hardly, if at all, distinguishable from P. longaeva, but its strongly conic-based cones with distinctly shorter-prickled, sunken-centered umbos at once distinguish it from that species.

Plants shown to be genetically distinct from the type (differences in chemistry, form, foliage, cone orientation, and seeds) have been called Pinus balfouriana subsp. austrina R.Mastrogiuseppe & J.Mastrogiuseppe. As in several other species or species complexes in Pinus, however, there is a problem with a character gradient involving related taxa. The evidence presented by D.K. Bailey (1970) and later by R.J. Mastrogiuseppe and J.D. Mastrogiuseppe (1980) could as well be used to indicate that P. balfouriana (with its two infraspecific taxa) and P. longaeva represent a single species of three subspecies or three varieties. The more conservative view of Bailey is followed here.

Of conservation concern.

Lower Taxa

None.