The Carlisle Mosquito Online

Friday, December 6, 2002


Eastern White Pine

If you have an evergreen tree on or near your property, it is very likely an eastern white pine, Pinus strobus. White pine grows in a variety of sites, from wetlands to well-drained sandy soils. The Carlisle Town Forest consists largely of white pine, which along with red pine (Pinus resinosa) were planted there back in the 1920s and '30s. You can easily identify eastern white pine because it has a cluster of five needles 3-5 inches long, and is the only native five-needled pine in the east. The red pine, in contrast, has two needles in a cluster. White pine is a valuable commercial wood, being used for doors, trim, mouldings, siding, and furniture.

White pine grows rapidly and can be 60 feet tall and 8-10 inches in diameter in 40 years. Trees can live well over 200 years and grow to be over 150 feet. If you visit the Carlisle Pines State Forest, you will see some very impressive white pines. We measured the diameter of one of the larger white pines (see photo) at about four feet above ground. It was 11 feet in circumference, implying a diameter of more than 3 feet. There are also a few large eastern hemlocks, the largest of which has a circumference of 11 feet 6 inches. Sidney Bull, writing in 1920, stated that some of the largest Carlisle pines were then believed to be 150-200 years old, and mature at the time of the American Revolution. Most of these large pines were probably toppled during the 1938 hurricane, leaving only a handful today. In colonial times, large white pines were reserved for the Royal Navy to be used as ship masts. According to Harlow, a white pine in Merrimack, New Hampshire, cut in 1736, measured 7 feet 8 inches in diameter at the butt!

The cones of the white pine require two years to mature, and reach a length of 4-8 inches. Each cone scale bears two winged seeds, which are eaten by birds and small mammals. If you find a pile of shelled white pine cones on a stump, it was probably the work of a red squirrel. White-footed mice and red-backed voles cache the seeds, and caches which escape depredation can produce seedlings. We have seen raccoons sleeping in the crotches of pines formed when the leader is broken off, allowing side branches to form a basket-shaped enclosure.

Certain species of hawks favor white pines for nest sites. We have seen the nests of sharp-shinned hawk, Cooper's hawk, red-tailed hawk, and northern goshawk in large white pines. We have also seen the huge nests (probably 6-8 feet in diameter) of bald eagles in very large pines, one near Damariscotta, Maine and another in Quabbin Reservoir in central Massachusetts. In the spring, you might hear the liquid trill of the pine warbler, which nests almost exclusively in pines. At Towle Field in Carlisle, we found the nest of an eastern bluebird which was constructed almost entirely of weathered white pine needles.

White pines often live in mycorrhizal relationships with fungi. In this symbiotic partnering between the rootlets of the tree and the fungi, the tree provides moisture and carbohydrates to the fungi, which in turn help the tree absorb phosphorus, inorganic nitrogen and other minerals. Trees without mycorrhizal fungi have less resistance to certain diseases. Right now, in the Carlisle Pines State Forest and in the Towle woods, the predominant mushroom is the Hygrophorus flavodiscus which is mycorrhizal with the pines. It looks a bit like a fried egg. Earlier in the year, you are likely to see other mycorrhizal mushrooms (in the genus Boletus, Amanita, Russula, Suillus, Cortinarius, Tricholoma and Lactarius) growing under pines. The bright yellow Suillus americanus, or chicken fat mushroom, is thought to be host-specific to the eastern white pine. (N.B.: Thanks to Kay Fairweather for this information.)

According to Harlow, white pine inner bark in May-June is good to chew, and New Englanders used to candy strips of it. Also, Harlow quotes Josyln, an early English writer as saying "the distilled water of the green cones taketh away wrinkles in the face, being laid on with cloths." I haven't tried either, but I'm getting old enough to consider the wrinkle treatment!


1. Sidney A. Bull, History of the Town of Carlisle, Murray Printing Co., Cambridge, MA, 1920, pp. 121-123.

2. William M. Harlow, Trees of the Eastern and Central United States and Canada, Dover Publications, New York, 1957, pp. 35-40.

3. Jennifer H. Carey, Pinus strobus, Fire Effects Information Service web site:

4. David Arora, Mushrooms Demystified, Ten Speed Press, 1986, pp. 6-7.

z Submissions for the Biodiversity Corner are encouraged and welcomed from all interested observers of nature. Think of it as your space to say a word or two on behalf of one of your favorite species. Just follow the format of today's column (or not) and send to Kay Fairweather at 392 School Street, Carlisle MA 01741 or to Don't hold back due to lack of drawings or photos.

2002 The Carlisle Mosquito