PITCH PINES.
Wood usually heavy, coarse-grained, generally dark-colored, with pale often thick sapwood; cones green at maturity (sometimes purple in 10 and 21) becoming various shades of brown; cone-scales more or less thickened, mostly armed; seeds shorter than their wings (except in 17 and 28); leaves with 2 fibro-vascular bundles.
Sheaths of the leaf-clusters deciduous; cones ½′—2′ long, maturing in the third year, leaves in 3-leaved clusters, slender, 2½′—4′ long.9. [P. leiophylla] (H). Sheaths of the leaf-clusters persistent. Leaves in 3-leaved clusters (3 and 5-leaved in 10, 3—2 leaved in 12). Cones subterminal, usually deciduous above the basal scales persistent on the branch. Buds brown; leaves in 2—5-leaved clusters.10. [P. ponderosa] (B, F, G, H). Buds white.11. [P. palustris] (C). Cones lateral. Cones symmetrical, their outer scales not excessively developed. Leaves in 2 and 3-leaved clusters, 8′—12′ long; cones short-stalked.12. [P. caribæa] (C). Leaves in 3-leaved clusters; cones sessile. Cones oblong-conic, prickles stout; leaves 6′—9′ long.13. [P. taeda] (A, C). Cones ovoid, prickles slender; leaves 3′—5′ long.14. [P. rigida] (A, C). Cones unsymmetrical by the excessive development of the scales on the outer side. Cones 5′—6′ long, their scales not prolonged into stout, straight or curved spines. Prickles of the cone-scales minute.15. [P. radiata] (G). Prickles of the cone-scales stout.16. [P. attenuata] (G). Cones 6′—14′ long, their scales prolonged into stout, straight or curved spines; leaves long and stout. Cones oblong-ovoid; seeds longer than their wings.17. [P. Sabiniana] (G). Cones oblong-conic; seeds shorter than their wings.18. [P. Coulteri] (G). Leaves in 2-leaved clusters (2 and 3-leaved in 23). Cones subterminal. Cones symmetrical, 2′—2½′ long, their scales unarmed; leaves 5′—6′ long.19. [P. resinosa] (A). Cones unsymmetrical by the greater development of the scales on the outer side, armed with slender prickles; leaves 1′—4′ long.20. [P. contorta] (B, F, G). Cones lateral. Cones about 2′ long. Cone-scales very unevenly developed and mostly unarmed; cones incurved; leaves less than 2′ long.21. [P. Banksiana] (A). Cone-scales evenly developed, armed with weak or deciduous prickles; leaves up to 4′ in length. Bark of the branches and upper trunk smooth.22. [P. glabra] (C). Bark of the branches and upper trunk roughened.23. [P. echinata] (A, C). Cones about 3′ long, armed with persistent spines. Cone-scales armed with slender or stout prickles. Cone-scales evenly developed, their prickles slender, acuminate, from a broad base; leaves 3′ long or less. Cones opening at maturity.24. [P. virginiana] (A, C). Cones often remaining closed for many years.25. [P. clausa] (C). Cone-scales unevenly developed and armed with stout prickles; cones 2′—3½′ long, remaining closed; leaves 4′—6′ long.26. [P. muricata.] Cone-scales armed with very stout hooked spines; cones 2½′—3′ long; opening in the autumn or remaining closed for two or three years; leaves 2′ long or less.27. [P. pungens.] Leaves in 5-leaved clusters; cones 4′—6′ long, unsymmetrical, their scales thick; seeds longer than their wings; leaves stout, 9′—13′ long.28. [P. Torreyana] (G).
9. [Pinus leiophylla] Schlecht. and Cham. Yellow Pine.
Pinus chihuahuana, Engelm.
Leaves slender, pale glaucous green, marked by 6—8 rows of conspicuous stomata on each of the 3 sides, 2½′—4′ long, irregularly deciduous from their fourth season, their sheaths deciduous. Flowers: male yellow; female yellow-green. Fruit ovoid, horizontal or slightly declining, long-stalked, 1½′—2′ long, becoming light chestnut-brown and lustrous, maturing at the end of the third season, with scales only slightly thickened, their ultimately pale umbos armed with recurved deciduous prickles; seeds oval, rounded above and pointed below, about ⅛′ long, with a thin dark brown shell, their wings ⅓′ long and broadest near the middle.
A tree, rarely more than 40°—50° high, with a tall trunk sometimes 2° in diameter, stout slightly ascending branches forming a narrow open pyramidal or round-topped head of thin pale foliage, and slender bright orange-brown branchlets, soon becoming dull red-brown. Bark of old trunks ¾′—1½′ thick, dark reddish brown or sometimes nearly black, and deeply divided into broad flat ridges covered with thin closely appressed scales. Wood light, soft, not strong but durable, light orange color, with thick much lighter colored sapwood. Often forming coppice by the growth of shoots from the stump of cut trees.
Distribution. Mountain ranges of southern New Mexico and Arizona, usually at elevations between 6000° and 7000°; not common; more abundant on the Sierra Madre of northern Mexico and on several of the short ranges of Chihuahua and Sonora, and of a larger size in Mexico than in the United States.