§ 2. Leaves in twos or threes, each with two fibro-vascular bundles; sheath close; woody scales of the cones thickened at the end and usually spiny-tipped.
[*] Cones lateral; their scales much thickened at the end; leaves rigid.
[+] Leaves in threes (rarely in twos in n. 2).
2. P. Tæ̀da, L. (Loblolly or Old-field Pine.) Leaves long (6–10´), with elongated sheaths, light green; cones elongated-oblong (3–5´ long) and tapering; scales tipped with a stout incurved spine.—Wet clay or dry sandy soil, Del. to Fla. near the coast, thence to Tex. and Ark.—A tree 50–150° high; staminate flowers slender, 2´ long, with usually 10–13 involucral scales; seeds with 3 strong rough ridges on the under side.
3. P. rígida, Mill. (Pitch Pine.) Leaves (3–5´ long) dark green, from short sheaths; cones ovoid-conical or ovate (1–3½´ long), often in clusters; scales with a short stout recurved prickle.—Sandy or barren soil, N. Brunswick to N. Ga., western N. Y. and E. Ky.—A tree 30–80° high, with very rough dark bark and hard resinous wood; sterile flowers shorter; scales 6–8.
[+][+] Leaves in twos (some in threes in n. 4 and 7).
4. P. púngens, Michx. f. (Table Mountain Pine.) Leaves stout, short (1¼–2½´ long), crowded, bluish, the sheath short (very short on old foliage); cones ovate (3½´ long), the scales armed with a strong hooked spine (¼´ long).—Alleghany Mts., Penn., to N. C. and Tenn.—A rather small tree (20–60° high); cones long-persistent.
5. P. ínops, Ait. (Jersey or Scrub Pine.) Leaves short (1½–3´ long); cones oblong-conical, sometimes curved (2–3´ long), the scales tipped with a straight or recurved awl-shaped prickle.—Barrens and sterile hills, Long Island to S. C., mostly near the coast, west through Ky. to S. Ind.—A straggling tree at the east, 15–40° high, with spreading or drooping branchlets; larger westward. Young shoots with a purplish glaucous bloom.
6. P. Banksiàna, Lambert. (Gray or Northern Scrub Pine.) Leaves short (1´ long), oblique, divergent; cones conical, oblong, usually curved (1½–2´ long), smooth, the scales pointless.—Barren sandy soil, S. Maine and N. Vt. to S. Mich., central Minn., and northward. Straggling shrub or low tree.
7. P. mìtis, Michx. (Yellow Pine.) Leaves sometimes in threes, from long sheaths, slender (3–5´ long); cones ovate- or oblong-conical (barely 2´ long), the scales with a minute weak prickle.—Usually dry or sandy soil, Staten Island to Fla., S. Ind., S. E. Kan. and Tex.—A straight tree, 50–100° high, with dark green leaves more soft and slender than the preceding. The western form has more rigid leaves and more tuberculate and spiny cones.