Pine Primer for the San Gabriel Mountains


Key
Descriptions
Sources

Pines are recognized by their evergreen, long, round, and thin needle-like leaves found in bundles wrapped in a papery sheath or sleeve.

These are the pine tree species native to the San Gabriel Mountains. If you find a pine that does not fit anything in the key or descriptions, chances are you found it along a paved road, or at a camp or picnic ground and the tree has been planted by the US Forest Service.

Bark texture and color change with age; texture is smooth and color is light when young, aging to rough, scaly and furrowed in texture and darker in color when old.

The number of records is an rough indicator of frequency. You are almost sure to see those with the largest number of observation records. Those with few records, in this case, are difficult to get to!

In the key below, remember that the leaves are needle-like.


Key

1. Is there only one leaf in the bundle?

2. Are there two leaves in the bundle?

3. Are there three leaves in the bundle? 5. Are the leaves less than 2" in length and in dense tufts near the ends of the branches? (See picture of the two species side by side (sugar on left; limber on right) to see what we mean by "dense tufts".)

However, it is often not easy to use this couplet in the field especially if you do not have the two species side by side. It is far better to use the bark and/or the pine cone to separate them:


Descriptions

We originally had links to give pictures of the species and their characteristics, but none of the links worked after a few years. So we removed the links, and instead recommend you go to Calphotos and look at their pictures for each species.

The number of records came from a search of Calflora back in ~2007, when there were very few vouchers online. The number of records for each species should be much higher now, but the relative number of records (comparing each species) should be roughly the same.

Pinus contorta subspecies murrayana


Pinus coulteri


Pinus flexilis


Pinus jeffreyi


Pinus lambertiana


Pinus monophylla


Pinus ponderosa


Pinus sabiniana


Sources and Other Information

CalFlora Occurrence Database. A search for Pinus in Los Angeles County in ~2007 yielded 120 observation records for the San Gabriel Mountains.

Conifers of California by Ronald M. Lanner. Cachuma Press, 1999.

Native Conifers of North America - California Conifers by Nearctica

A California Flora by Philip A. Munz. University of California Press, 1968.

Roadside Plants of Southern California by Thomas J. Belzer. Mountain Press Publishing Company, 1984.

Sierra Nevada Natural History by Tracy I. Storer and Robert L. Usinger. University of California Press, 1963.

Trees and Shrubs of California (California Natural History Guides) by John D. Stuart (Author), John O. Sawyer (Author), Andrea J. Pickart (Illustrator)

Pacific Coast Tree Finder: A Pocket Manual for Identifying Pacific Coast Trees (Nature Study Guides) 2nd Edition by Tom Watts.


Go to Keys to Identifying Selected Plant Groups in the SGM


Copyright © 2000-2017 by Jane Strong and Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
http://tchester.org/sgm/plants/keys/pine.html
Comments and feedback: Tom Chester
Updated 23 October 2017