Pinus ponderosa subsp. benthamiana description

Distribution map (USGS 1999 showing approximate extent of the different P. ponderosa subspecies; benthamiana shown in green..

Pinus ponderosa subsp. benthamiana not yet formally described

Common Names

Ponderosa pine (Kral 1993), Pacific race ponderosa.

Taxonomic notes

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 1847 as Pinus benthamiana Hartweg.

It is locally sympatric with and occasionally hybridizes with P. jeffreyi, but hybrids are rare and in areas of sympatry it usually occurs at lower elevations than P. jeffreyi (Kral 1993).

Description

"Trees to 72 m; trunk to 2.5 m diam. Twigs commonly red-brown, not glaucous. Buds very resinous. Leaves mainly 3 per fascicle, 12-25(-30) cm x (1.2-)1.5-2 mm. Pollen cones mostly red. Seed cones 8-15 cm, symmetric; apophyses of fertile scales moderately raised; umbo low-pyramidal, tapering acuminately to short broad-based prickle. Seed body 6-9 mm; wing 15-25 mm" (Kral 1993).

Range

USA: Washington and Oregon west of the Cascade crest, California, particularly in the Sierra Nevada but also in a few areas in the Coast Ranges; south nearly to the Mexican border (M.P. Frankis, pers. comm. Dec-1998). Habitat montane, dry, open forests at 0-2300 m (Kral 1993).

Big Tree

The largest volume, 126 m³, is found in the Grizzly Meadow Monarch, which grows along the West Fork Chiquito Creek in Sierra National Forest, California. It has a 222 cm dbh and is 68.0 meters tall. The smaller Hartman's Bar tree (117 m³), growing on the Hartman's Bar Trail in Plumas National Forest, California, has a 237 cm dbh and is 69.2 meters tall. The Bear Creek Twin along the Bear Creek Trail in Trinity Alps Wilderness, California, has a volume of 115 m³, dbh of 238 cm, and is 68.0 meters tall. The tallest known tree is much taller than these: 78.9 meters for a tree in the Big Pine Campground, Siskiyou National Forest, in (surprise!) Oregon (Van Pelt 2000).

Oldest

Dendrochronology

Ethnobotany

A valuable timber tree, the harvest of which far exceeds regrowth because of high timber value and multiple uses of the wood (Kral 1993).

Observations

Since the species is so common within its range, only a few choice locales can be mentioned here. It can be seen at low montane elevations in Sequoia, Kings Canyon and Yosemite National Parks and in Calaveras Big Trees State Park, all in California. The Calaveras forests are particularly noteworthy because a prescribed fire program has been implemented in the park. Consequently, the stands include examples of open pine forest understory with pine seedling regeneration. Such a sight has not been seen in many American ponderosa stands this century, due to widespread fire suppression that seems to have doomed many of our finest ponderosa forests to replacement by more shade-tolerant conifers such as Abies grandis. The pine forests of California were eloquently described by John Muir (1894). At Fort Lewis, Washington, it grows west of the Cascade Mountains due to edaphic drought conditions created by an extremely porous glacial outwash substrate.

Remarks

It is the largest and stateliest yellow pine in North America (Kral 1993).