State Rank Reason (see State Rank above)
Western white pine populations have been severely impacted by the introduced pathogen, white pine blister rust, and from historic timber harvesting. Currently, western white pine is present in eight counties of central and western Montana, but at populations much lower than historic levels. It is found on federal, state, private, non-government organization, and tribal lands within its Montana range. The USFS (Region 1) and the MT DNRC is actively engaged in management and research to conserve western white pine, as is some private landowners. The USFS and MT DNRC plant rust-resistant seedlings and implement forest practices to retain healthy individuals. Planted seedlings are about 66% resistant to the rust. While the trend in the number of western white pine trees is improving, it may still be at levels insufficient to maintain a long-term genetic viability across its range. Data from private lands and timber companies is needed.
Trees: Large tree to 60 m tall (Lesica 2012), a trunk diameter of up to 2 ½ feet (FNA 1993), with a conical to rounded crown (Lesica 2012).
Bark, Branches, and Buds: Bark thin, smooth (Lesica 2012) and grey at first (Douglas et al. 1998), developing markedly scaly plates (FNA 1993); scale plates square to rectangular (Cronquist et al. 1986), greyish where exposed and rusty brown underneath (Douglas et al. 1998). Branches sloping upwards or spreading, almost verticillate; twigs slender, somewhat glandular, minutely pubescent, light reddish-brown, turning grey or brownish-purple (FNA 1993). Buds acute, ovoid (Cronquist et al. 1986) to cylindric, reddish cinnamon-brown, a little sticky with resin, 4-5 mm in length (FNA 1993).
Leaves: Light blue-green, 4–10 cm long, 5 needles per fascicle (Lesica 2012), straight or lightly twisted, flexible (FNA 1993), slender, glaucous, remaining about 2-4 years (Cronquist et al. 1986); stomatal lines visible on adaxial but not the abaxial surface (FNA 1993); margins frequently with tiny teeth; leaf sheaths deciduous (Cronquist et al. 1986).(Lesica’s contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
Mesic montane forests of western Montana (Lesica 2012); also in fog forests of low-lying areas. Elevation: 0-9850 feet (FNA 1993).(Lesica’s contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
Western white pine is a long-lived tree. However, it is sensitive to fire, susceptible to blister rust, and cannot thrive in shade (Lesica 2012).(Lesica’s contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
Cones: Male cones yellow, 10-15 mm in length (FNA 1993); female cones narrowly elliptic, 15-25 cm in length (Lesica 2012), clustered, resinous, light brown to yellowish (FNA 1993), hanging pendulously on somewhat long stalks in the upper branches (Cronquist et al. 1986), ripening in 2 years, and dropping shortly after seed dispersal.
Seeds: Seed body reddish-brown, 5-7 mm; wing 2-2.5 cm (FNA 1993).(Lesica’s contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
Western white pine is the principal western resource used for matchwood (FNA 1993).