P. ponderòsa.
8. Pìnus ponderòsa, Dougl. (Western Yellow or Heavy-wooded Pine.) Leaves in threes, 5 to 10 in. long, from short sheaths; broad, coarse, twisted, flexible, of a deep green color; branchlets thick, reddish brown. Cones 3 to 4 in. long, ovate, reflexed, clustered on short stems. Scales long, flattened, with small, sharp, recurved prickles. A large Pacific coast species, 100 to 300 ft. high, with rather coarse-grained, hard and heavy, whitish wood, and thick, deeply furrowed bark; beginning to be cultivated east.
P. paltústris.
9. Pìnus palústris, Mill. (Long-leaved or Southern Yellow Pine.) Leaves 3 together in bundles, 10 to 15 in. long, from a long, lacerated, light-colored sheath, of a bright green color, and crowded in dense clusters at the ends of the branches. Cones 6 to 10 in. long, usually cylindric, of a beautiful brown color, with thick scales, armed with very small, slightly recurved prickles. A rather tall pine, 75 ft. high, wild in the Southern States, and cultivated as far north as New Jersey, in sheltered situations.
P. rígida.
10. Pìnus rígida, Mill. (Pitch-pine.) Leaves in threes, 3 to 5 in. long, from short sheaths; rigid and flattened. Cones ovate, 1 in. to nearly 4 in. long, sometimes in clusters; scales with a short, recurved prickle. A medium-sized tree, 40 to 70 ft. high, with hard, coarse-grained, very resinous wood; found east of the Alleghanies throughout; more abundant in swamps.
P. Austrìaca.