=Habitat and Range.=--Most common in dry, sterile soils, occasional in swamps. New Brunswick to Lake Ontario. Maine,--mostly in the southwestern section near the seacoast; as far north as Chesterville, Franklin county (C. H. Knowlton, _Rhodora_, II, 124); scarcely more than a shrub near its northern limits; New Hampshire,--most common along the Merrimac valley to the White mountains and up the Connecticut valley to the mouth of the Passumpsic, reaching an altitude of 1000 feet above the sea level; Vermont,--common in the northern Champlain valley, less frequent in the Connecticut valley (_Flora of Vermont_, 1900); common in the other New England states, often forming large tracts of woodland, sometimes exclusively occupying extensive areas. South to Virginia and along the mountains to northern Georgia; west to western New York, Ohio, Kentucky, and Tennessee. =Habit.=--Usually a low tree, from 30 to 50 feet high, with a diameter of 1-2 feet at the ground, but not infrequently rising to 70-80 feet, with a diameter of 2-4 feet; trunk straight or more or less tortuous, tapering rather rapidly; branches rising at a wide angle with the stem, often tortuous, and sometimes drooping at the extremities, distinctly whorled in young trees, but gradually losing nearly every trace of regularity; roughest of our pines, the entire framework rough at every stage of growth; head variable, open, often scraggly, widest near the base and sometimes dome-shaped in young trees; branchlets stout, terminating in rigid, spreading tufts of foliage. [Illustration: PLATE II.--Pinus Strobus.] =Bark.=--Bark of trunk in old trees thick, deeply furrowed, with broad connecting ridges, separating on the surface into coarse dark grayish or reddish brown scales; younger stems and branches very rough, separating into scales; season's shoots rough to the tips. =Winter Buds and Leaves.=--Leading branch-buds 1/2-3/4 inch long, narrow-cylindrical or ovate, acute at the apex, resin-coated; scales brownish. Foliage leaves in threes, 3-5 inches long, stout, stiff, dark yellowish-green, 3-sided, sharp-pointed, with two fibrovascular bundles; sessile; sheaths when young about 1/2 inch long. =Inflorescence.=--Sterile flowers at the base of the season's shoots, clustered; stamens numerous; anthers yellow: fertile flowers at a slight angle with and along the sides of the season's shoots, single or clustered. =Fruit.=--Cones lateral, single or in clusters, nearly or quite sessile, finally at right angles to the stem or twisted slightly downward, ovoid, ovate-conical; subspherical when open, ripening the second season; scales thickened at the apex, armed with stout, straight or recurved prickles.