Distribution map (USGS 1999 showing approximate extent of the different P. ponderosa subspecies; brachyptera shown in purple.
Pinus ponderosa subsp. brachyptera
Rocky Mountain yellow pine (Peattie 1950), Rocky Mountain ponderosa pine (Kral 1993).
Although here treated as a subspecies, this taxon is yet to be formally published as a subspecies within P. ponderosa. It was separately described in 1848 as Pinus brachyptera Engelmann.
Many authorities (e.g., Kral 1993) assign both P. ponderosa subsp. brachyptera and P. ponderosa subsp. scopulorum to a single taxon, P. ponderosa var. scopulorum. However, the two subspecies are readily distinguished on the basis of number of needles per fascicle (normally three in this taxon, but two in subsp. scopulorum) and cone characters (see description below).
This subspecies intergrades with subsp. scopulorum at the northern limits of its range, and with Pinus arizonica in Arizona, New Mexico, and south just into Sonora in Mexico (Kral 1993; also refs. under P. ponderosa main page).
Trees to 24 m tall and 1.5 m diam. Twigs mostly red-brown, rarely glaucous. Leaves mainly 3 per fascicle, 10-17 cm × 1.4-2 mm. "Pollen cones yellow. Seed cones mostly symmetric, 5-10 cm; apophyses of fertile scales moderately raised; umbo low pyramidal, narrowing acuminately to a stout-based prickle or short sharp spur. Seed body 3-4 mm; wing to 15 mm" (Kral 1993). Cones are slightly larger and more glossy in texture than those of subsp. scopulorum.
USA: New Mexico and Arizona; Mexico: N Sonora.
Probably a specimen from the Malpais Lava Beds National Monument.
Widely enountered throughout most of its range. In my experience, especially noteworthy occurrences include: (a) the Malpais Lava Beds National Monument of New Mexico, where some of the oldest known trees are found and (b) the plateaus of northern Arizona and New Mexico, where ponderosa provided the forests that were used in building the Anasazi civilization 900 years ago.
This species is the most important principal host for the dwarf mistletoe Arceuthobium vaginatum subsp. cryptopodum (Hawksworth and Wiens 1996).
Thanks to M.P. Frankis for his help with the Taxonomic Notes, 1998.12.
Friederici, Peter (ed.). 2005. Ecological Restoration of Southwestern Ponderosa Pine Forests. Washington, DC: Island Press.