Pacific Northwest Native Plant Profile: Pine (Pinus species)


Well over one hundred species of pine help support our planet, which makes the genus Pinus the largest within the conifer phylum known as Pinophyta, the woody cone-bearing plants. Found across the Northern Hemisphere, Pinus is of ancient origin, having appeared around 180 million years ago. In addition to the rich wildlife habitat, beauty, shade, fragrance, rain interception and carbon sequestration they provide, the majority of pines are drought tolerant, fire resistant and most can be extremely long-lived, with some species surviving 1,000+ years when undisturbed.

How they grow
Evergreen and resinous, pines generally grow 50–150 ft tall, although some, like ponderosa pine, can grow over 200 feet (one in southern Oregon’s Rogue River-Siskiyou National Forest towers to more than 268 feet tall!).

On adult pine trees, needle-like leaves are green and bundled in clusters called fascicles, unlike other conifers. Each fascicle can have one to seven needles, depending on the species, and assist in identification. In the Pacific Northwest west of the Cascades, there are five native pine species, a few of which can also be found at fairly high elevations east of the Cascades summit. They have either two, three, or five needles per fascicle, which stay on the plant for anywhere from two to forty years, again depending on the species.

Seed cones (female) are hard and woody, with tough scales that serve to protect the developing seeds until dispersal time comes. In some species, maturity of the cone causes scales to open and free the winged seeds. In others, scales need to be broken or pecked open by a hungry animal in order for the seeds to be released. And then there are the species that have scales sealed shut with resin: Known as “serotinous” cones, they need a trigger to release their seeds. Although serotiny can be caused in some plants by excessively moist or dry conditions, high solar heat, or death of a branch or the plant, most pines that are native to regions where wildfire naturally occurs depend on the high temperatures from periodic fire to soften the resin and expose the seeds. Fire has been a part of various natural ecosystems for millennia; having a canopy full of seeds ready to go following a fire ensures dispersal for a new generation without competition. But it can take decades for that to happen and on many sites currently, such fire regimes no longer exist. When natural fire is suppressed, species that need fire to regenerate will slowly die without ever releasing their seeds, and species dependent on those pines are consequently affected.

Pines do best in open areas and are not shade-tolerant. Generally, they don’t need rich soil and do best if it drains fairly quickly. Some can survive in harsh environments such as cold, exposed ridges at high elevations or latitudes, or even the wet and windy Pacific coast.

Wildlife value
Pines are one of the most valuable food plants for wildlife in the Pacific Northwest, particularly for small mammals like chipmunks and squirrels, as well as birds such as grosbeaks, jays, chickadees, and nuthatches who forage on the highly nutritious seeds and help distribute them. Larger birds, including woodpeckers, also use pine trees as food sources, particularly dead and dying pines. Pine needles may be eaten by some Lepidoptera (butterfly and moth) species (such as the larvae of western pine elfin that use lodgepole and ponderosa pine for food), as well as by pine sawfly, deer, and mountain goats; needles are also used in nest building. Large pines provide excellent roost and nest sites, while smaller pines offer crucial cover for many animals. Fallen needles may serve as bedding for larger mammals such as deer.

Native pines west of the Cascades
Below is info on the five native pine species that occur in the PNW west of the Cascades, plus one honorable mention; they are noted according to the number of needles per fascicle. If you want to identify a particular tree, count the needles per fascicle, evaluate the appearance of the cones, and check the natural range.

Fast-growing Pinus contorta evolved into four varieties, each of which adapted to its geography. Despite their large ecological and morphological variability, all varieties of P. contorta have two stiff, one to three-inch long needles per fascicle, which are often twisted and are mostly found toward the ends of twigs. The seed cones are small (typically one to three inches long), hard, prickled toward the top of the cone, and found near branch tips. The varieties are inter fertile in areas where their ranges overlap.

Pinus contorta var. contorta

Three varieties are found in the PNW. It was shore pine (a.k.a. beach pine or twisted pine), Pinus contorta var. contorta, that led David Douglas to offer the species’ epithet contorta when he first laid eyes on one in 1826: Reportedly, he found some relatively short trees growing in contorted and gnarly outlines near the mouth of the Columbia River on wind-swept, rocky sites with the added insult of oceanic salt spray. Bark is thick, deeply grooved, and a deep red-brown in color. Small brown cones are often asymmetrical and release seeds at maturity. Adapted to poor and rocky soils, shore pine’s range includes the San Juan islands, the outer coasts of British Columbia, Oregon, Washington and northern California, bogs of Alaska and Washington, and only occasionally the Puget-Willamette Trough. On more sheltered sites, this coastal species will grow taller and more erect (up to about 50 feet tall), and slightly resembles the appearance of Pinus contorta var. latifolia (lodgepole pine), which naturally occurs further inland, mainly in the Washington Cascades east of the Puget Trough and at higher elevations (up to 11,500 feet).

Lodgepole pine grows taller (up to ~100 feet) and more slender (especially when growing close together) with thin bark and a narrow crown. Adapted to stand-destroying fire, it is one of the first trees to come back after a natural periodic fire; its cones, which vary in shape and may be solitary or paired, are considered fire-dependent. However, this cone characteristic varies with tree age and local fire history, with older trees and those growing in areas with frequent fires able to produce serotinous cones. Remarkably, some lodgepole pine trees are even more variable, having both serotinous and nonserotinous cones, which may enable future trees to adapt to change.

Pinus contorta var. murrayana, Sierra-Cascade lodgepole pine, grows in the eastern Cascades of southern Washington, Oregon and the mountains of California. Its cones usually open on the tree when mature, before a fire. Both lodgepole pines will grow in situations that other conifers cannot tolerate.

Another tall, handsome pine is Pinus ponderosa, or ponderosa pine (aka western yellow pine), a fairly fast-growing tree to 100 feet by 25 feet in cultivation, larger in natural areas. With bundles of three long, pointed bright green needles that fall off after several years, ponderosa pine has a straight, robust trunk and a wide, open, cylindrical crown when mature. Bark is furrowed and dark on young trees; on older trees the thick, fire-resistant bark typically turns a golden brown or cinnamon color, flakes off into scaly plates separated by deep fissures, and has a vanilla scent in heat. Tan to reddish-brown, conical or egg-shaped female cones have stiff prickles that curve outward. The root system spreads widely and has a deep taproot. Although best grown in full sun with well drained, deep, somewhat moist soil when young, ponderosa pine is reportedly adaptable to a variety of elevations, soil and humidity, and is drought tolerant when established. Damage may occur due to late frosts.

Lustrous needles of Pinus ponderosa subsp. Benthamiana.

Ponderosa pine is subdivided into five subspecies; P. ponderosa subsp. ponderosa is most commonly found in cold, dry environments east of the Cascade summit, throughout the Rocky Mountains and southward. Pinus ponderosa subsp. Benthamiana (aka Pacific ponderosa) is endemic to the Willamette Valley (where it is sometimes called Willamette Valley pine or Pinus ponderosa var. willamettensis), as well as the mountains of southwestern Oregon, parts of California and a few sites in western Washington. Genetically different from ponderosa subspecies in other ecoregions, it usually has longer needles (up to nine inches) and is suited to higher rainfall in valley bottoms, as well as drier slopes. Prior to 1850, it thrived in oak savanna, riparian forest and upland prairie dispersed among other species (particularly Oregon white oak, Quercus garryana). Logged extensively by settlers as they cleared the land for lumber, agriculture and other development, until recently the only remaining native stock in the Willamette Valley survived in small scattered stands. Wildlife who needed the trees for food and nesting habitat suffered from the loss, including the rapidly dwindling Lewis’s woodpecker (now extirpated; there have been no breeding records in the Puget Lowlands since 1980; the last known nest in the Willamette Valley was near Scapoose in 1970; they have not been seen in the Rogue and Umpqua Valleys since the early 1990s). While this pine does best in full sun and moist but well-draining soil, it also tolerates somewhat dry conditions and lean soils. Choose associate species from Oregon white oak (Quercus garryana) ecosystems in this post.

Another three-needled pine that possesses similarities to ponderosa pine is Jeffrey pine, Pinus jeffreyi, named by Scottish botanist John Jeffrey. A major difference is its range: In the PNW it occurs only in southwestern Oregon at 4800 to 9600 feet in elevation, often in windswept outcroppings or on serpentine and other nutrient-poor soils where it grows slowly but outcompetes other trees. In addition, its needles are a duller bluish-gray and thicker than ponderosa pine’s, and they are typically held longer (five to eight years). Cones become much larger (up to 12 inches long), with prickles that curve inward. Older bark tends to be darker and more narrowly grooved than that of ponderosa’s.

Pinus attenuata (knobcone pine) also has fascicles of three yellow-green needles, which are typically three to seven inches in length and twisted. Buff colored, three to six inch, serotinous cones — that let go of seeds only after fire melts the resin — have knobby bumps on one side, and grow in bristly, dense clusters. Bark is dark with loose, scaly plates on this very long-lived, relatively small (30 to 50 foot) tree with a conical crown; it may be shrubby on poor sites. In the PNW west of the Cascades it’s found mainly in southwestern Oregon on rocky slopes at high elevations that are prone to fire (often on serpentine soils), as well as further south into parts of California and Baja.

Pinus lambertiana (sugar pine) is a very large tree (120 to 200 feet tall) that has fascicles of five pointed needles that are two to four inches in length and striped with white on all three sides. Woody cones are straight and grow very large (up to 19 inches), with straight, thick scales. Bark is reddish-brown to purplish and furrowed; on young trees it’s broken into narrow plates and on mature trees broken into long plates. It’s found at mid to high elevations in the mountains of southern Oregon (from Linn County, southward), as well as southern California, the Sierra Nevada range and northern Baja. David Douglas named the species lambertiana in honor of the English botanist Aylmer Bourke Lambert in 1826.

You may be familiar with Pinus monticola, Western white pine, since it is fairly easy to grow (despite its susceptibility to white pine blister-rust). A large, symmetrical tree (to 130 feet but smaller in cultivation), it also has fascicles of five needles, but white pine’s thin bluish-green needles have (surprise!) white lines on two sides of each 3-sided needle. Slender, curved woody cones are four to ten inches long, with scales that are thin and may be curved but without prickles. Bark is gray, thin, and broken into small rectangular or hexagonal scaly plates on mature trees. Range includes southern British Columbia, Washington, Oregon, and California’s Sierra Nevada, from sea level to about 2500 feet in elevation in moist valleys and open slopes.

The very slow-growing, often shrub-like or gnarled Pinus albicaulis (whitebark pine) also has short needles in bundles of five, thin grayish bark, and small roundish cones without prickles that remain closed on the tree at any age. Since it naturally occurs only at high elevations (near timberline) in southern B.C, the Olympics, the Cascades, east-central California and the Rocky Mountains, you won’t be tempted to grow it in your low elevation yard, but I’ll mention it as it certainly deserves our attention and concern.

Data from USFS Forest Inventory and Analysis surveys report that “as of 2016, 51% of all standing whitebark pine trees in the US were dead” and over half of that amount occurred approximately within the last two decades. Due to severe population decline, the USFWS determined that it “warrants protection under the Endangered Species Act (ESA), but … adding the species to the Federal List of Endangered and Threatened Wildlife and Plants is precluded by the need to address other listing actions of a higher priority.” The severe decline is attributed to multiple stressors, especially white pine blister rust (introduced into western North America through the horticulture trade in 1910 from Europe), but also outbreaks of mountain pine beetle (made worse by a warming climate), fire suppression and catastrophic fire, poor management, and, of course, climate chaos. UPDATE: In December 2022, this species was listed as threatened under the federal Endangered Species Act.

Whitebark pine is very long-lived, with some surviving 1,000 years. Considered a keystone species, it regulates runoff by slowing down snowmelt, controls soil erosion due to its ability to grow quickly after disturbances such as fires, and provides a rich source of food for birds like Clark’s nutcracker and mammals such as grizzly bears. It depends almost exclusively on Clark’s nutcracker for seed dispersal, but there needs to be sufficient density and seed abundance to attract the birds. More info here.

Try pines at home
If you want to add pines to your landscape, remember that it’s best to grow native trees and other plants that truly belong in your neck o’ the woods. Obtain plants propagated from source material that originated as close as possible to your site and with similar habitat features. Using such “local genotypes” helps ensure that you get plants that are well adapted to your area and preserves the genetic diversity that helps plants and animals adapt to changing conditions. Ask growers and nurseries about their sources if you’re unsure.

Provide good drainage and enough sun and space (both above and below ground) for these beauties. Whenever possible, grow them with their natural associate species, which have similar needs, to recreate a native plant community that is able to impart the most benefits to the ecosystem and result in more habitat for wildlife. And if you have the space, plant a grove!

© 2022 Eileen M. Stark

7 thoughts on Pacific Northwest Native Plant Profile: Pine (Pinus species)

  1. Wonderful article. Any suggestions on where to get advice for native only landscaping in the Seaside OR area?

    Reply
    1. I’m not sure what kind of advice you need, but you might try Aldervale Native Plants in Nehalem, as well as the Clatsop Soil Water Conservation District. Thanks for growing local natives!

      Reply
  2. Thank you. This is a very helpful overview of PNW pines with enough depth to make the best choices for gardeners and help with Identification.

    Reply
  3. thank you for Eileen, I enjoyed that. I have pinus contorta on my property in Newport. I look forward to your next posting

    Reply

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