TREES OF NORTH AMERICA
(Exclusive of Mexico)

Class 1. GYMNOSPERMÆ.

Ovules and seeds borne on the face of a scale, not inclosed in an ovary; resinous trees, with stems increasing in diameter by the annual addition of a layer of wood inside the bark.

I. PINACEÆ.

Trees, with narrow or scale-like generally persistent clustered or alternate leaves and usually scaly buds. Flowers appearing in early spring, mostly surrounded at the base by an involucre of the more or less enlarged scales of the buds, unisexual, monœcious (diœcious in Juniperus), the male consisting of numerous 2-celled anthers, the female of scales bearing on their inner face 2 or several ovules, and becoming at maturity a woody cone or rarely a berry. Seeds with or without wings; seed-coat of 2 layers; embryo axile in copious albumen; cotyledons 2 or several. Of the twenty-nine genera scattered over the surface of the globe, but most abundant in northern temperate regions, thirteen occur in North America.

CONSPECTUS OF THE NORTH AMERICAN GENERA.

Scales of the female flowers numerous; spirally arranged in the axils of persistent bracts; ovules 2, inverted; seeds borne directly on the scales, attached at the base in shallow depressions on the inner side of the scales, falling from them at maturity and usually carrying away a scarious terminal wing; leaves fascicled or scattered (deciduous in Larix). Abietineæ.

Fruit maturing in two or rarely in three seasons; leaves fascicled, needle-shaped in axillary 1—5-leaved clusters, inclosed at the base in a membranaceous sheath; cone-scales thick and woody, much longer than their bracts.

1. Pinus.

Fruit maturing in one season.

Leaves in many-leaved clusters on short spur-like branchlets, deciduous; cone-scales thin, usually shorter than their bracts.

2. Larix.

Leaves scattered, linear.

Cones pendulous, the scales persistent on the axis.

Branchlets roughened by the persistent leaf-bases; leaves deciduous in drying; bracts shorter than the cone-scales.

Leaves sessile, 4-sided, or flattened and stomatiferous above.

3. Picea.

Leaves stalked, flattened and stomatiferous below, or angular.

4. Tsuga.

Branchlets not roughened by leaf-bases; leaves stalked, flattened; not deciduous in drying; bracts of the cone 2-lobed, aristate, longer than the scales.

5. Pseudotsuga.

Cones erect, their scales deciduous from the axis, longer or shorter than the bracts; leaves sessile, flat or 4-sided.

6. Abies.

Scales of the female flowers without bracts; ovules and seeds borne on the face of minute scales adnate to the base of the flower-scales, enlarging and forming the scales of the cone. Seeds with a narrow marginal wing (wingless in Juniperas).

Scales of the female flowers numerous, spirally arranged, forming a woody cone; ovules erect, 2 or many under each scale; leaves linear, alternate, often of 2 forms (deciduous in Taxodium). Taxodiæ.

Ovules and seeds numerous under each scale.

7. Sequoia.

Ovules and seeds 2 under each scale; leaves mostly spreading in 2 ranks.

8. Taxodium.

Scales of the female flower few, decussate, forming a small cone, or rarely a berry; ovules 2 or many under each scale; leaves decussate or in 3 ranks, often of 2 forms, usually scale-like, mostly adnate to the branch, the earliest free and subulate. Cupressineæ.

Fruit a cone; leaves scale-like.

Cones oblong, their scales oblong, imbricated or valvate; seeds 2 under each scale, maturing the first year.

Scales of the cone 6, the middle ones only fertile; seeds unequally 2-winged.

9. Libocedrus.

Scales of the cone 8—12; seeds equally 2-winged.

10. Thuja.

Cones subglobose, the scales peltate, maturing in one or two years; seeds few or many under each scale.

Fruit maturing in two seasons; seeds many under each scale; branchlets terete or 4-winged.

11. Cupressus.

Fruit maturing in one season; seeds 2 under each scale; branchlets flattened.

12. Chamæcyparis.

Fruit a berry formed by the coalition of the scales of the flower; ovules in pairs or solitary; flowers diœcious; leaves decussate or in 3’s, subulate or scale-like, often of 2 forms.

13. Juniperus.

1. PINUS Duham. Pine.

Trees or rarely shrubs, with deeply furrowed and sometimes laminate or with thin and scaly bark, hard or often soft heartwood often conspicuously marked by dark bands of summer cells impregnated with resin, pale nearly white sapwood, and large branch-buds formed during summer and composed of minute buds in the axils of bud-scales, becoming the bracts of the spring shoot. Leaves needle-shaped, clustered, the clusters borne on deciduous spurs in the axils of scale-like primary leaves, inclosed in the bud by numerous scales lengthening and forming a more or less persistent sheath at the base of each cluster. Male flowers clustered at the base of leafy growing shoots of the year, each flower surrounded at the base by an involucre of 3—6 scale-like bracts, composed of numerous sessile anthers, imbricated in many ranks and surmounted by crest-like nearly orbicular connectives; the female subterminal or lateral, their scales in the axils of non-accrescent bracts. Fruit a woody cone maturing at the end of the second or rarely of the third season, composed of the hardened and woody scales of the flower more or less thickened on the exposed surface (the apophysis), with the ends of the growth of the previous year appearing as terminal or dorsal brown protuberances or scars (the umbo). Seeds usually obovoid, shorter or longer than their wings or rarely wingless; outer seed-coat crustaceous or thick, hard, and bony, the inner membranaceous; cotyledons 3—18, usually much shorter than the inferior radicle.

Pinus is widely distributed through the northern hemisphere from the Arctic Circle to the West Indies, the mountains of Central America, the Canary Islands, northern Africa, the Philippine Islands, and Sumatra. About sixty-six species are recognized. Of exotic species the so-called Scotch Pine, Pinus sylvestris L., of Europe and Asia, the Swiss Stone Pine, Pinus cembra L., and the Austrian Pine and other forms of Pinus nigra Arnold, from central and southern Europe, are often planted in the northeastern states, and Pinus Pinaster Ait., of the coast region of western France and the Mediterranean Basin is successfully cultivated in central and southern California. Pinus is the classical name of the Pine-tree.

The North American species can be conveniently grouped in two sections, Soft Pines and Pitch Pines.

SOFT PINES.

Wood soft, close-grained, light-colored, the sapwood thin and nearly white; sheaths of the leaf-clusters deciduous; leaves with one fibro-vascular bundle.

Leaves in 5-leaved clusters.

Cones long-stalked, elongated, cylindric bright green at maturity, becoming light yellow brown, their scales thin, with terminal unarmed umbos; seeds shorter than their wings. White Pines.

Leaves without conspicuous white lines on the back.

Leaves slender, flexible; cones 4′—8′ long.

1. P. Strobus (A).

Leaves stout, more rigid; cones 5′—11′ long.

2. P. monticola (B, G).

Leaves with conspicuous white lines on the back; cones 12′—18′ long.

3. P. Lambertiana (G).

Cones short-stalked, green or purple at maturity, their scales thick.

Cones cylindric or subglobose, their scales with terminal umbos; leaves 2′ long or less. Stone Pines.

Cones 3′—10′ long, their scales opening at maturity; seeds with wings.

4. P. flexilis (F, H).

Cones ½′—3′ long, their scales remaining closed at maturity; seeds wingless.

5. P. albicaulis (B, F, G).

Cones ovoid-oblong, their scales with dorsal umbos armed with slender prickles; seeds shorter than their wings; leaves in crowded clusters, incurved, less than 2′ long. Foxtail Pines.

Cones armed with minute incurved prickles.

6. P. Balfouriana (G).

Cones armed with long slender prickles.

7. P. aristata (F, G).

Leaves in 1—4-leaved clusters; cones globose, green at maturity, becoming light brown, their scales few, concave, much thickened, only the middle scales seed-bearing; seeds large and edible, their wings rudimentary; leaves 2′ or less, often incurved. Nut Pines.

8. P. cembroides (C, F, G, H).

1. Pinus Strobus L. White Pine.

Leaves soft bluish green, whitened on the ventral side by 3—5 bands of stomata, 3′—5′ long, mostly turning yellow and falling in September in their second season, or persistent until the following June. Flowers: male yellow; female bright pink, with purple scale margins. Fruit fully grown in July of the second season, 4′—8′ long, opening and discharging its seeds in September; seeds narrowed at the ends, ¼′ long, red-brown mottled with black, about one fourth as long as their wings.

A tree, while young with slender horizontal or slightly ascending branches in regular whorls usually of 5 branches; at maturity often 100°, occasionally 220° high, with a tall straight stem 3°—4° or rarely 6° in diameter, when crowded in the forest with short branches forming a narrow head, or rising above its forest companions with long lateral branches sweeping upward in graceful curves, the upper branches ascending and forming a broad open irregular head, and slender branchlets coated at first with rusty tomentum, soon glabrous, and orange-brown in their first winter. Bark on young stems and branches thin, smooth, green tinged with red, lustrous during the summer, becoming 1′—2′ thick on old trunks and deeply divided by shallow fissures into broad connected ridges covered with small closely appressed purplish scales. Wood light, not strong, straight-grained, easily worked, light brown often slightly tinged with red; largely manufactured into lumber, shingles, and laths, used in construction, for cabinet-making, the interior finish of buildings, wooden ware, matches, and the masts of vessels.

Distribution. Newfoundland to Manitoba, southward through the northern states to Pennsylvania, northern and eastern (Belmont County) Ohio, northern Indiana, valley of the Rocky River near Oregon, Ogle County, Illinois, and central and southeastern Iowa, and along the Appalachian Mountains to eastern Kentucky and Tennessee and northern Georgia; forming nearly pure forests on sandy drift soils, or more often in small groves scattered in forests of deciduous-leaved trees on fertile well-drained soil, also on the banks of streams, or on river flats, or rarely in swamps.

Largely planted as an ornament of parks and gardens in the eastern states, and in many European countries, where it grows with vigor and rapidity; occasionally used in forest planting in the United States.

2. Pinus monticola D. Don. White Pine.

Leaves blue-green, glaucous, whitened by 2—6 rows of ventral and often by dorsal stomata, mostly persistent 3 or 4 years. Flowers: male yellow; female pale purple. Fruit 5′—11′ long, shedding its seeds late in the summer or in early autumn; seeds narrowed at the ends, ⅓′ long, pale red-brown mottled with black, about one third as long as their wings.

A tree, often 100° or occasionally 150° high, with a trunk frequently 4°—5° or rarely 7°—8° in diameter, slender spreading slightly pendulous branches clothing young stems to the ground and in old age forming a narrow open often unsymmetrical pyramidal head, and stout tough branchlets clothed at first with rusty pubescence, dark orange-brown and puberulous in their first and dark red-purple and glabrous in their second season. Bark of young stems and branches thin, smooth, light gray, becoming on old trees ¾′—1½′ thick and divided into small nearly square plates by deep longitudinal and cross fissures, and covered by small closely appressed purple scales. Wood light, soft, not strong, close, straight-grained, light brown or red; sometimes manufactured into lumber, used in construction and the interior finish of buildings.

Distribution. Scattered through mountain forests from the basin of the Columbia River in British Columbia to Vancouver Island; on the mountains of northern Washington to the western slopes of the Rocky Mountains of northern Montana; on the coast ranges of Washington and Oregon; and on the Cascade and Sierra Nevada ranges southward to the Kern River valley, California; most abundant and of its greatest value in northern Idaho on the bottom-lands of streams tributary to Lake Pend Oreille; reaching the sea-level on the southern shores of the Straits of Fuca and elevations of 10,000° on the California Sierras.

Often planted as an ornamental tree in Europe, and occasionally in the eastern United States where it grows more vigorously than any other Pine-tree of western America.

3. Pinus Lambertiana Dougl. Sugar Pine.

Leaves stout, rigid, 3½′—4′ long, marked on the two faces by 2—6 rows of stomata; deciduous during their second and third years. Flowers: male light yellow; female pale green. Fruit fully grown in August and opening in October, 11′—18′ or rarely 21′ long; seeds ½′—⅝′ long, dark chestnut-brown or nearly black, and half the length of their firm dark brown obtuse wings broadest below the middle and ½′ wide.

A tree, in early life with remote regular whorls of slender branches often clothing the stem to the ground and forming an open narrow pyramid; at maturity 200°-220° high, with a trunk 6°—8° or occasionally 12° in diameter, a flat-topped crown frequently 60° or 70° across of comparatively slender branches sweeping outward and downward in graceful curves, and stout branchlets coated at first with pale or rufous pubescence, dark orange-brown during their first winter, becoming dark purple-brown. Bark on young stems and branches thin, smooth, dark green, becoming on old trunks 2′—3′ thick and deeply and irregularly divided into long thick plate-like ridges covered with large loose rich purple-brown or cinnamon-red scales. Wood light, soft, straight-grained, light red-brown; largely manufactured into lumber and used for the interior finish of buildings, woodwork, and shingles. A sweet sugar-like substance exudes from wounds made in the heartwood.

Distribution. Mountain slopes and the sides of ravines and cañons; western Oregon from the valley of the north branch of the Santiam River southward on the Cascade and coast ranges; California along the northern and coast ranges to Sonoma County; along the western slopes of the Sierra Nevada, where it grows to its greatest size at elevations between 3000° and 7000°; reappearing on the Santa Lucia Mountains of the coast ranges; and on the high mountains in the southwestern part of the state from Santa Barbara County southward usually at elevations of 5000°—7000° above the sea; and on the San Pedro Mártir Mountains in Lower California.

Occasionally planted as an ornamental tree in western Europe and in the eastern states, the Sugar Pine has grown slowly in cultivation and shows little promise of attaining the large size and great beauty which distinguish it in its native forests.

4. Pinus flexilis James. Rocky Mountain White Pine.

Pinus strobiformis Sarg., not Engelm.

Leaves stout, rigid, dark green, marked on all sides by 1—4 rows of stomata, 1½′—3′ long, deciduous in their fifth and sixth years. Flowers: male reddish; female clustered, bright red-purple. Fruit subcylindric, horizontal or slightly declining, green or rarely purple at maturity, 3′—10′ long, with narrow and more or less reflexed scales opening at maturity; seeds compressed, ⅓′—½′ long, dark red-brown mottled with black, with a thick shell produced into a narrow margin, their wings about ¹/₁₂′ wide, generally persistent on the scale after the seed falls.

A tree, usually 40°—50°, occasionally 80° high, with a short trunk 2°—5° in diameter, stout long-persistent branches ultimately forming a low wide round-topped head, and stout branchlets orange-green and covered at first with soft fine pubescence, usually soon glabrous and darker colored; at high elevations often a low spreading shrub. Bark of young stems and branches thin, smooth, light gray or silvery white, becoming on old trunks 1′—2′ thick, dark brown or nearly black, and divided by deep fissures into broad ridges broken into nearly square plates covered by small closely appressed scales. Wood light, soft, close-grained, pale clear yellow, turning red with exposure; occasionally manufactured into lumber.

Distribution. Eastern slope of the Rocky Mountains from Alberta to western Texas and westward on mountain ranges at elevations of 5000° to 12,000° to Montana, and southern California, reaching the western slopes of the Sierra Nevada at the head of King’s River near the summit of San Gorgonio Mountain and in Snow Cañon, San Bernardino Range; usually scattered singly or in small groves; forming open forests on the eastern foothills of the Rocky Mountains of Montana and on the ranges of central Nevada; attaining its largest size on those of northern New Mexico and Arizona.

5. Pinus albicaulis Engelm. White Pine.

Leaves stout, rigid, slightly incurved, dark green, marked by 1—3 rows of dorsal stomata, clustered at the ends of the branches, 1½′—2½′ long, persistent for from five to eight years. Flowers opening in July, scarlet. Fruit ripening in August, oval or subglobose, horizontal, sessile, dark purple, 1½′—3′ long, with scales thickened, acute, often armed with stout pointed umbos, remaining closed at maturity; seeds wingless, acute, subcylindric or flattened on one side, ⅓′—½′ long, ⅓′ thick, with a thick dark chestnut-brown hard shell.

A tree, usually 20°—30° or rarely 60° high, generally with a short trunk 2°—4° in diameter, stout very flexible branches, finally often standing nearly erect and forming an open very irregular broad head, and stout dark red-brown or orange-colored branchlets puberulous for two years or sometimes glabrous; at high elevations often a low shrub, with wide-spreading nearly prostrate stems. Bark thin, except near the base of old trunks and broken by narrow fissures into thin narrow brown or creamy white plate-like scales. Wood light, soft, close-grained, brittle, light brown. The large sweet seeds are gathered and eaten by Indians.

Distribution. Alpine slopes and exposed ridges between 5000° and 12,000° elevation, forming the timber-line on many mountain ranges from latitude 53° north in the Rocky Mountains and British Columbia, southward to the Wind River and Salt River Ranges, Wyoming, the mountains of eastern Washington and Oregon, the Cascade Range, the mountains of northern California and the Sierra Nevada to Mt. Whitney.

6. Pinus Balfouriana Balf. Foxtail Pine.

Leaves stout, rigid, dark green and lustrous on the back, pale and marked on the ventral faces by numerous rows of stomata, 1′—1½′ long, persistent for ten or twelve years. Flowers: male dark orange-red; female dark purple. Fruit 3½′—5′ long, with scales armed with minute incurved prickles, dark purple, turning after opening dark red or mahogany color; seeds full and rounded at the apex, compressed at the base, pale, conspicuously mottled with dark purple, ⅓′ long, their wings narrowed and oblique at the apex, about 1′ long and ¼′ wide.

A tree, usually 30°—40° or rarely 90° high, with a trunk generally 1°—2° or rarely 5° in diameter, short stout branches forming an open irregular pyramidal picturesque head, and long rigid more or less spreading puberulous, soon glabrous, dark orange-brown ultimately dark gray-brown or nearly black branchlets, clothed only at the extremities with the long dense brush-like masses of foliage. Bark thin, smooth, and milky white on the stems and branches of young trees, becoming on old trees sometimes ¾′ thick, dark red-brown, deeply divided into broad flat ridges. broken into nearly square plates separating on the surface into small closely appressed scales. Wood light, soft and brittle, pale reddish brown.

Distribution. California, on rocky slopes and ridges, forming scattered groves on Scott Mountain, Siskiyou County, at elevations of 5000°—6000°; on the mountains at the head of the Sacramento River; on Mt. Yolo Bally in the northern Coast Range, and on the southern Sierra Nevada up to elevations of 11,500°, growing here to its largest size and forming an extensive open forest on the Whitney Plateau east of the cañon of Kern River, and at the highest elevations often a low shrub, with wide-spreading prostrate stems.

7. Pinus aristata Engelm. Foxtail Pine. Hickory Pine.

Leaves stout or slender, dark green, lustrous on the back, marked by numerous rows of stomata on the ventral faces, 1′—1½′ long, often deciduous at the end of ten or twelve years or persistent four or five years longer. Flowers male dark orange-red; female dark purple. Fruit 3′—3½′ long, with scales armed with slender incurved brittle prickles nearly ¼′ long, dark purple-brown on the exposed parts, the remainder dull red, opening and scattering their seeds about the 1st of October; seeds nearly oval, compressed, light brown mottled with black, ¼′ long, their wings broadest at the middle, about ⅓′ long and ¼′ wide.

A bushy tree, occasionally 40°—50° high, with a short trunk 2°—3° in diameter, short stout branches in regular whorls while young, in old age growing very irregularly, the upper erect and much longer than the usually pendulous lower branches, and stout light orange-colored, glabrous, or at first puberulous, ultimately dark gray-brown or nearly black branchlets clothed at the ends with long compact brush-like tufts of foliage. Bark thin, smooth, milky white on the stems and branches of young trees, becoming on old trees ½′—¾′ thick, red-brown, and irregularly divided into flat connected ridges separating on the surface into small closely appressed scales. Wood light, soft, not strong, light red; occasionally used for the timbers of mines and for fuel.

Distribution. Rocky or gravelly slopes at the upper limit of tree growth and rarely below 8,000° above the sea from the outer range of the Rocky Mountains of Colorado to those of southern Utah, central and southern Nevada, southeastern California, and the San Francisco peaks of northern Arizona.

8. Pinus cembroides Zucc. Nut Pine. Piñon.

Leaves in 2 or 3-leaved clusters, slender, much incurved, dark green, sometimes marked by rows of stomata on the 3 faces, 1′—2′ long, deciduous irregularly during their third and fourth years. Flowers: male in short crowded clusters, yellow; female dark red. Fruit subglobose, 1′—2′ broad; seeds subcylindric or obscurely triangular, more or less compressed at the pointed apex, full and rounded at base, nearly black on the lower side and dark chestnut-brown on the upper, ½′—¾′ long, the margin of their outer coat adnate to the cone-scale.

A bushy tree, with a short trunk rarely more than a foot in diameter and a broad round-topped head, usually 15°—20° high, stout spreading branches, and slender dark orange-colored branchlets covered at first with matted pale deciduous hairs, dark brown and sometimes nearly black at the end of five or six years; in sheltered cañons on the mountains of Arizona and in Lower California occasionally 50° or 60° tall. Bark about ½′ thick, irregularly divided by remote shallow fissures and separated on the surface into numerous large thin light red-brown scales. Wood light, soft, close-grained, pale clear yellow. The large oily seeds are an important article of food in northern Mexico, and are sold in large quantities in Mexican towns.

Distribution. Mountain ranges of central and southern Arizona, usually only above elevations of 6500°, often covering their upper slopes with open forests; in an isolated station on the Edwards Plateau on uplands and in cañons at the headwaters of the Frio and Nueces Rivers, Edwards and Kerr Counties, Texas; on the Sierra de Laguna, Lower California, and on many of the mountain ranges of northern Mexico; passing into the following varieties differing only in the number of the leaves in the leaf-clusters, and in their thickness.

Pinus cembroides var. Parryana Voss. Nut Pine. Piñon.

Pinus quadrifolia Sudw.

Leaves in 1—5 usually 4-leaved clusters, stout, incurved, pale glaucous green, marked on the three surfaces by numerous rows of stomata, 1¼′—1½′ long, irregularly deciduous, mostly falling in their third year.

A tree, 30°—40° high, with a short trunk occasionally 18′ in diameter, and thick spreading branches forming a compact regularpyramidal or in old age a low round-topped irregular head, and stout branchlets coated at first with soft pubescence, and light orange-brown. Bark ½′—¾′ thick, dark brown tinged with red, and divided by shallow fissures into broad flat connected ridges covered by thick closely appressed plate-like scales. Wood light, soft, close-grained, pale brown or yellow. The seeds form an important article of food for the Indians of Lower California.

Distribution. Arid mesas and low mountain slopes of Lower California southward to the foothills of the San Pedro Mártir Mountains, extending northward across the boundary of California to the desert slopes of the Santa Rosa Mountains, Riverside County, where it is common at elevations of 5000° above the sea-level.

Pinus cembroides var. edulis Voss. Nut Pine. Piñon.

Pinus edulis Engelm.

Leaves in 2 or rarely in 3-leaved clusters, stout, semiterete or triangular, rigid, incurved, dark-green, marked by numerous rows of stomata, ¾′—1½′ long, deciduous during the third or not until the fourth or fifth year, dropping irregularly and sometimes persistent for eight or nine years.

A tree often 40°—50° high with a tall trunk occasionally 2° in diameter and short erect branches forming a narrow head, or frequently with a short divided trunk and a low round-topped head of spreading branches, and thick branchlets orange color during their first and second years, finally becoming light gray or dark brown sometimes tinged with red. Bark ½′—¾′ thick and irregularly divided into connected ridges covered by small closely appressed light brown scales tinged with red or orange color. Wood light, soft, not strong, brittle, pale brown; largely employed for fuel and fencing, and as charcoal used in smelting; in western Texas occasionally sawed into lumber. The seeds form an important article of food among Indians and Mexicans, and are sold in the markets of Colorado and New Mexico.

Distribution. Eastern foothills of the outer ranges of the Rocky Mountains, from northern Colorado (Owl Cañon, Larimer County); to the extreme western part of Oklahoma (near Kenton, Cimarron County, G. W. Stevens) and to western Texas, westward to eastern Utah, southwestern Wyoming, and to northern and central Arizona; over the mountains of northern Mexico, and on the San Pedro Mártir Mountains, Lower California; often forming extensive open forests at the eastern base of the Rocky Mountains, on the Colorado plateau, and on many mountain ranges of northern and central Arizona up to elevations of 7000° above the sea.

Pinus cembroides var. monophylla Voss. Nut Pine. Piñon.

Pinus monophylla Torr.

Leaves in 1 or 2-leaved clusters, rigid, incurved, pale glaucous green, marked by 18—20 rows of stomata, usually about 1½′ long, sometimes deciduous during their fourth and fifth seasons, but frequently persistent until their twelfth year.

A tree usually 15°—20°, occasionally 40°—50° high, with a short trunk rarely more than a foot in diameter and often divided near the ground into several spreading stems, short thick branches forming while the tree is young a broad rather compact pyramid, and in old age often pendulous and forming a low round-topped often picturesque head, and stout light orange-colored ultimately dark brown branchlets. Bark about ¾′ thick and divided by deep irregular fissures into narrow connected flat ridges broken on the surface into thin closely appressed light or dark brown scales tinged with red or orange color. Wood light, soft, weak, and brittle; largely used for fuel, and charcoal used in smelting. The seeds supply an important article of food to the Indians of Nevada and California.

Distribution. Dry gravelly slopes and mesas from the western base of the Wasatch Mountains of Utah, westward over the mountain ranges of Nevada to the eastern slopes of the southern Sierra Nevada, and to their western slope at the headwaters of the Tuolumne, Kings and Kern Rivers, and southward to northern Arizona and to the mountains of southern California where it is common on the San Bernardino and San Jacinto Mountains between altitudes of 3500° and 7000°, and on the Sierra del Pinal, Lower California; often forming extensive open forests at elevations between 5000° and 7000°.

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.

10. Pinus ponderosa Laws. Yellow Pine. Bull Pine.

Leaves tufted at the ends of naked branches, in 2 or in 2 and 3-leaved clusters, stout, dark yellow-green, marked by numerous rows of stomata on the 3 faces, 5′—11′ long, mostly deciduous during their third season. Flowers: male yellow; female clustered or in pairs, dark red. Fruit ellipsoidal, horizontal or slightly declining, nearly sessile or short-stalked, 3′—6′ long, often clustered, bright green or purple when fully grown, becoming light reddish brown, with narrow scales much thickened at the apex and armed with slender prickles, mostly falling soon after opening and discharging their seeds, generally leaving the lower scales attached to the peduncle; seeds ovoid, acute, compressed at the apex, full and rounded below, ¼′ long, with a thin dark purple often mottled shell, their wings usually broadest below the middle, gradually narrowed at the oblique apex, 1′—1¼′ long, about 1′ wide.

A tree, sometimes 150°—230° high, with a massive stem 5°—8° in diameter, short thick many-forked often pendulous branches generally turned upward at the ends and forming a regular spire-like head, or in arid regions a broader often round-topped head surmounting a short trunk, and stout orange-colored branchlets frequently becoming nearly black at the end of two or three years. Bark for 80—100 years broken into rounded ridges covered with small closely appressed scales, dark brown, nearly black or light cinnamon-red, on older trees becoming 2′—4′ thick and deeply and irregularly divided into plates sometimes 4°—5° long and 12′—18′ wide, and separating into thick bright cinnamon-red scales. Wood hard, strong, comparatively fine-grained, light red, with nearly white sapwood sometimes composed of more than 200 layers of annual growth; largely manufactured into lumber used for all sorts of construction, for railway-ties, fencing, and fuel.

Distribution. Mountain slopes, dry valleys, and high mesas from northwestern Nebraska and western Texas to the shores of the Pacific Ocean, and from southern British Columbia to Lower California and northern Mexico; extremely variable in different parts of the country in size, in the length and thickness of the leaves, size of the cones, and in the color of the bark. The form of the Rocky Mountains (var. scopulorum, Engelm.), ranging from Nebraska to Texas, and over the mountain ranges of Wyoming, eastern Montana and Colorado, and to northern New Mexico and Arizona, where it forms on the Colorado plateau with the species the most extensive Pine forests of the continent, has nearly black furrowed bark, rigid leaves in clusters of 2 or 3 and 3′—6′ long, and smaller cones, with thin scales armed with slender prickles hooked backward. More distinct is

Pinus ponderosa var. Jeffreyi Vasey.