Identification guide to the 5 needle pines of western North America

Whitebark pine (Pinus albicaulis), a high-elevation 5 needle pine.

This page presents an identification guide to the 5 needle pines the occur in western North America. This guide has been produced in conjunction with The Whitebark Pine Project and the 5-Needle Pines Along the Pacific Crest Trail Project, and in collaboration with the Whitebark Pine Ecosystem Foundation, and is designed to be used to identify 5 needle pines in western North America.

Five needle pines are conifer trees in the genus Pinus with needles that occur in bundles (fascicles) of 5. There are 9 species of 5 needle pine in western North America (Kral 2022) (Table 1). Of these, 6 are considered “High 5 Pines“; that is 5 needles pines that occur at high-elevation, typically above 1,500 m +/- 200 m (4,921 ft +/- 656 ft) above sea level.

This guide consists of 3 parts:
1. A location-based guide to the 5 needle pines of western North America.
2. Descriptions and photos of the 5 needle pines of western North America.
3. A guide to the anatomy of a pine tree.

Identification Guide

Location-based Guide

The first part of this guide is based on location. Step 1 is to use the below key to determine if the tree you’d like to identify is a 5 needle pine. The key follows from the first section of the key to Pinaceae in Kral et al. (2022). For a description of terms used in the key see the Guide to the Anatomy of a Pine Tree, below.

Step 1 – Key to Conifer Types

Step 2 – Select Location

If indeed the tree is a 5 needle pine, then click a state, province, or country from the list of buttons below to see the 5 needle pines that occur there, and a dichotomous key to aid in identification. The buttons are ordered alphabetically left to right, and are color coded by region.

For a comprehensive key to all pine species in North America please refer to the Pinus section (Kral 2022) of the Flora of North America.

Descriptions and Photos

The second part of this guide provides descriptions and photos of the 5 needle pines of western North America listed in Table 1, below. Click the link for the species of interest to go the description page.

Table 1. Five-needle pines of western North America.

Scientific NameCommon NameGeneralized RangeHigh 5 Pine?
Pinus albicaulisWhitebark PineAlberta, B.C., California, Idaho, Montana, Nevada, Oregon, Washington, WyomingTRUE
Pinus aristataRocky Mountain Bristlecone PineArizona, Colorado, New MexicoTRUE
Pinus balfourianaFoxtail PineCaliforniaTRUE
Pinus flexilisLimber PineAlberta, Arizona, B.C., California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Utah, WyomingTRUE
Pinus lambertianaSugar PineCalifornia, Mexico, Nevada, OregonFALSE
Pinus longaevaGreat Basin Bristlecone PineCalifornia, Nevada, UtahTRUE
Pinus monticolaWestern White PineAlberta, B.C., California, Idaho, Montana, Nevada, Oregon, WashingtonFALSE
Pinus strobiformisSouthwestern white pineArizona, Mexico, New Mexico, TexasTRUE
Pinus torreyanaTorrey PineCaliforniaFALSE
Table 1. Five-needle pines of western North America.

Two additional pine species, Pinus engelmannii (Apache pine) and Pinus quadrifolia (Parry pine) occasionally have 5 needles/fascicle, and therefore may be confused with the true 5 needle pines (Kral 2022). However, these 2 species typically have 3 and 4 needles/fascicle, respectively, and both species have a narrow geographic range that doesn’t overlap much with the geographic ranges of the true 5 needle pines. P. engelmannii occurs in southeast Arizona, southwest New Mexico, and adjacent Mexico; while P. quadrifolia occurs in extreme southern California, and Mexico in Baja California.

For a comprehensive key to all pine species in North America please refer to the Pinus section (Kral 2022) of the Flora of North America.

A Guide to the Anatomy of a Pine Tree

This section provides a brief overview of the anatomy of a pine tree. Some of the terms in this section are used in the dichotomous key in the location-based guide and on the species description page.

Pines are in a group of plants called gymnosperms that produce seeds via cones rather than by flowers as in angiosperms. The term gymnosperm literally means “naked seed,” referring to the fact that the seeds are not enclosed in an ovary. Gymnosperms have male cones (“pollen cones”) that produce pollen, and female cones (“seed cones”) that house the egg and, after pollination, produce the seeds. The males cones are generally much smaller than the female cones Figures 1 and 2.

Figure 1. The cluster of scarlet male cones of a whitebark pine (Pinus
albicaulis) on Goat Peak in north-central Washington State.
Each cones is about the size of a small grape.
Figure 2. Female cone of a whitebark pine (Pinus albicaulis) near Cutthroat Pass in north-central Washington State. This cone is about the size of a baseball.

Female pine cones are attached to the branches by a peduncle, and have a central axis called a rachis. Female cone scales arise from the rachis in a spiral pattern. Nearly all pine species require 2 years for their cones to reach maturity. Female cone scales are composed of 2 parts, the umbo and apophysisis. The umbo is the first year’s growth and is located at the end of the apophysisis, which is the second year’s growth. The outer part of the apophysisis is thickened relative to the inner part in some pine species, and the umbo is either dorsal or terminal, and in some species may be “armed” with a stout prickle. Figure 3 shows a few photos of pine cone morphology.

The seeds are produced on the inside of the scale which in turn protect the seeds as they develop. As the seeds are developing the cone scales remain appressed against the axis and are thus “closed.”

When the seeds are ripe the cone scales of many pine species will open on their own and thus release the seeds. Some pine species require fire to open the cones, a term called serotinous, as in some lodgepole pine (Pinus contorta) cones. Other pine species have cones that don’t readily open on their own and instead rely on animals to pull apart the scales, as is typical with whitebark pine (Pinus albicaulis). The seeds of some pine species are winged, while other species lack a seed wing (Figure 4).

Winged seeds of ponderosa pine (P. ponderosa; not a 5 needle pine)
Figure 5. Five needles per bundle (fascicle) is what differentiates 5 needle pines from other pines. This photo is a fascicle of western white pine (Pinus monticola) from north-central Washington.

Pines are needleleaf, evergreen trees in the genus Pinus. As the terms needleleaf and evergreen suggest, the leaves of pines are long and needle-like, and remain green through all seasons. Pine needles occur in bundles called fascicles that are held together at the base by a sheath (Figure 5). The number of needles per fascicle varies between species, and 5 needle pines are differentiated from other pine species in that they have 5 needles per fascicle.

Literature Cited

Kral, R. 2022. Pinus. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. New York and Oxford. Vol. 2. Accessed [2022-12-17].


Copyright Aaron Wells 2022

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