Chapter VI: Part II: Classification of the Species (2)

There is, however, no difficulty in fixing the systematic position of
these exceptional species through other characters which show their
true affinity. They are placed with the species which they most
resemble. Their exceptional characters are merely the evidence of the
evolution that pervades and unites the groups. Therefore the
definition of a group is not necessarily the exact definition of its
species, and a species is placed in a group because all its
characters, specific and evolutional, show a closer affinity with that
group than with the species of any other.

=X. LARICIONES=

Pits of the ray-cells large. Cells of the leaf-hypoderm uniform. Spring-shoots uninodal. Cones dehiscent at maturity.

This group represents the first stage in the evolution of the Hard
Pines. All the species, like the Soft Pines, are uninodal and the
cones are dehiscent at maturity, but the trend toward the serotinous
species is shown in the occasional appearance of the oblique cone as a
varietal form of a few species, and in the persistent cone of the last
two species of this group.

All the species of this group are of the Old World except P. resinosa
and P. tropicalis. These two are the only American Pines combining
large pits with dentate tracheids, and are the only American Hard
Pines with external resin-ducts of the leaf.

Cones deciduous at maturity.
Cones ovate or ovate-conic.
Conelet with tuberculate or entire scales.
Resin-ducts external and medial 25. resinosa
Resin-ducts septal and external 26. tropicalis
Conelet with mucronate scales.
Resin-ducts mostly external.
Conelet pedunculate, erect.
Cone nut-brown 27. Massoniana
Cone dull tawny yellow 28. densiflora
Conelet pedunculate, reflexed 29. sylvestris
Conelet subsessile, erect 30. montana
Resin-ducts mostly medial.
Bark-formation late 31. luchuensis
Bark-formation early.
Cone nut-brown 32. Thunbergii
Cone lustrous tawny yellow 33. nigra
Cones narrow cylindrical 34. Merkusii
Cones tenaciously persistent.
Leaves stout, relatively short 35. sinensis
Leaves slender, relatively long 36. insularis

25. PINUS RESINOSA

1789 P. resinosa Aiton, Hort. Kew. iii. 367.
1810 P. rubra Michaux f. Hist. Arbr. Am. i. 45, t. 1.

Spring-shoots uninodal. Leaves binate, from 12 to 17 cm. long; resin-ducts external or external and medial; hypoderm uniform and inconspicuous. Scales of the conelet mutic. Cones from 4 to 6 cm. long, subsessile, symmetrical, deciduous the third year, leaving a few basal scales on the tree; apophyses sublustrous, nut-brown, somewhat thickened along a transverse keel.

From Nova Scotia and Lake St. John this species ranges westward to the
Winnipeg River and southward into Minnesota, Michigan, northern New
York and eastern Massachusetts, with rare occurrence on the mountains
of Pennsylvania. Under cultivation it is a beautiful tree, adapted to
cold-temperate climates. It was considered by Loiseleur (1812) and by
Spach (1842) to be a variety of P. nigra (laricio). The two species
vary in the color of the cone, the anatomy of the leaves, the buds,
and in the armature of the conelet. A fallen cone of this species is
moreover usually imperfect from the loss of a few basal scales.

Plate XIX.

Fig. 170, Cone and enlarged conelet. Fig. 171, Leaf-fascicle and
magnified leaf-section.

26. PINUS TROPICALIS

1851 P. tropicalis Morelet in Rev. Hort. Cote d'Or, i. 105.
1904 P. terthrocarpa Shaw in Gard. Chron. ser. 3, xxxv. 179, f. 74.

Spring-shoots uninodal. Leaves binate, sometimes ternate, from 15 to 30 cm. long, rigid, erect; hypoderm of uniform thick-walled cells; resin-ducts of remarkable size, septal, or not quite touching the endoderm and technically external. Scales of the conelet minutely tuberculate. Cones from 5 to 8 cm. long, short-pedunculate, erect or patulous; ovate-conic, symmetrical; apophyses rufous brown, low-pyramidal, the umbo mutic.

Growing at sea-level within the tropics and confined to western Cuba
and the Isle of Pines. On the island it is associated with P.
caribaea. This species needs no other means of identification than its
peculiar leaf-section. Septal ducts are found in P. oocarpa, Pringlei,
Merkusii and rarely in other species, but they never attain the
extraordinary size that appears to be invariable in P. tropicalis.

Plate XIX.

Fig. 172, Cone and enlarged conelet. Fig. 173, Branch with leaves,
much reduced. Fig. 174, Leaf-fascicle and magnified leaf-section.
Fig. 175, Trees on the Isle of Pines.

27. PINUS MASSONIANA

1803 P. Massoniana Lambert, Gen. Pin. i. 17, t. 12. 1861 P. canaliculata Miquel in Jour. Bot. Neerland. i. 86.

Spring-shoots uninodal. Leaves binate, rarely ternate, from 12 to 20 cm. long, slender and pliant; hypoderm inconspicuous; resin-ducts external. Staminate catkins often in long dense clusters. Conelets partly tuberculate or mucronate, partly mutic. Cones symmetrical, from 4 to 7 cm. long, ovate-conic, short-pedunculate, early deciduous; apophyses sublustrous, nut-brown, flat or somewhat elevated, the umbo usually mutic.

The Chinese Red Pine is found in warm-temperate climates. It is native
to southeastern China and follows the valley of the Yangtse River into
Szech'uan. It has been confused by London with P. pinaster, which it
resembles in no respect, by Siebold with P. Thunbergii, from which it
differs in leaf-dimensions and in leaf-section, and by Mayr with his
P. luchuensis, whose peculiar cortex and whose leaf-section has no
counterpart among Chinese Hard Pines. Its nearest relative is P.
densiflora, from which it differs in its longer leaves, in the color
of its cone and in its conelet (Plate XX, figs. 176, 179).

Plate XX.

Fig. 176, Cone and enlarged conelet. Fig. 177, Two leaf-fascicles.
Fig. 178, Magnified leaf-section.

28. PINUS DENSIFLORA

1842 P. densiflora Siebold & Zuccarini, Fl. Jap. ii. 22, t. 112.
1854 P. scopifera Miquel in Zollinger, Syst. Verz. Ind. Archip. 82.

Spring-shoots more or less pruinose, uninodal. Leaves binate, from 8 to 12 cm. long, slender; hypoderm of few inconspicuous cells; resin-ducts external. Staminate catkins in long dense clusters. Scales of the conelet conspicuously mucronate. Cones symmetrical, from 3 to 5 cm. long, ovate-conic, often persistent for a few years but with a weak hold on the branch; apophyses dull pale tawny yellow, flat or slightly elevated, the mucro more or less persistent.

The Japanese Red Pine forms extensive forests on the mountains of
central Japan. It is perfectly hardy in cold-temperate climates. Wild
specimens of China, ascribed to this species, are forms of the
variable P. sinensis. From P. Massoniana it differs in its shorter
leaves and yellow cone, but particularly in the more prominent
prickles and thicker scales of its conelet (figs. 176, 179).

Plate XX.

Fig. 179, Cones and enlarged conelet. Fig. 180, Leaf-fascicles. Fig.
181, Magnified leaf-section and more magnified dermal tissues of the
leaf.

29. PINUS SYLVESTRIS

1753 P. sylvestris Linnaeus, Sp. Pl. 1000 (excl. var.).
1768 P. rubra Miller, Gard. Dict. ed. 8.
1768 P. tatarica Miller, Gard. Dict. ed. 8.
1781 P. mughus Jacquin, Icon. Pl. Rar. i. t. 193 (not Scopoli).
1798 P. resinosa Savi, Fl. Pisa. ii. 354 (not Aiton).
1827 P. humilis Link in Abhandl. Akad. Berlin, 171.
1849 P. Kochiana Klotzsch in Linnaea, xxii. 296.
1849 P. armena Koch in Linnaea, xxii. 297.
1849 P. pontica Koch in Linnaea, xxii. 297.
1859 P. Frieseana Wichura in Flora, xlii. 409.
1906 P. lapponica Mayr, Fremdl. Wald- & Parkb. 348.

Spring-shoots uninodal. Leaves binate, from 3 to 7 cm. long; hypoderm inconspicuous; resin-ducts external. Conelet reflexed, minutely mucronate. Cones from 3 to 6 cm. long, reflexed, symmetrical or sometimes oblique, ovate-conic, deciduous; apophyses dull pale tawny yellow of a gray or greenish shade, flat, elevated or protuberant and often much more prominent on the posterior face of the cone, the umbo with a minute prickle or its remnant.

A tree of great commercial value, with a very extended range, from
Norway, Scotland and southern Spain to northeastern Siberia. A
vigorous hardy species and extensively cultivated. The red upper
trunk, characteristic of this Pine, is not invariable. The dark upper
trunk is sufficiently common to be considered a varietal form
(Mathieu, Flore Forest. ed. 4, 582). In various localities may be
found trees bearing oblique cones, their apophyses showing various
degrees of protuberance up to the extreme development represented in
Loudon's illustration of the variety uncinata (Arb. Brit. iv, f.
2047). This cone is the beginning of the changes that culminate in
species with oblique cones only. In P. sylvestris, however, the
purpose of this form of cone is not apparent except in connection with
this evolution.

Plate XXI.

Figs. 182, 183, Cones. Fig. 184, Leaf-fascicle, magnified
leaf-section and more magnified dermal tissues of the leaf. Fig.
185, Habit of the tree.

30. PINUS MONTANA

1768 P. montana Miller, Gard. Dict. ed. 8.
1772 P. mughus Scopoli, Fl. Carn. ii. 247.
1791 P. pumilio Haenke in Jirasek, Beobacht. 68.
1804 P. mugho Poiret in Lamarck, Encycl. Meth. v. 336.
1805 P. uncinata Ramond ex De Candolle, Lamarck, Fl. Franc. ed. 3,
iii. 726.
1813 P. sanguinea Lapeyrouse, Hist. Pl. Pyren. 587.
1827 P. rotundata Link in Abhandl. Akad. Berlin, 168.
1830 P. obliqua Sauter ex Reichenbach, Fl. Germ. Exc. 159.
1837 P. uliginosa Neumann ex Wimmer, Arb. Schles. Ges. 95.

Spring-shoots uninodal. Leaves binate, from 3 to 8 cm. long, the epiderm very thick, hypoderm weak; resin-ducts external. Conelets mucronate, nearly sessile. Cones from 2 to 7 cm. long, subsessile, ovate or ovate-conic, symmetrical or oblique, often persistent; apophyses lustrous tawny-yellow or dark brown, both colors often shading into each other on the same cone, flat, prominent or prolonged into uncinate beaks of various lengths, the last much more developed on the posterior face of the cone, the umbo bordered by a narrow dark ring and bearing the remnant of the mucro.

P. montana grows as a bush or as a small tree, the two forms often
associated. It ranges from central Spain through the Pyrenees, Alps
and Apennines to the Balkan Mountains, associated with P. cembra at
higher, with P. sylvestris at lower altitudes. It grows indifferently
in bogs and on rocky slopes. Its dwarf form, under the name of the
Mugho Pine, is extensively cultivated as a garden ornament.

On the differences of the cone this species has been divided into
three subspecies: uncinata, with an oblique cone and protuberant
apophyses; pumilio, with a symmetrical cone and an excentric umbo;
mughus, with a symmetrical cone and a concentric umbo. Other
segregations based on the degree of development of the apophysis and
on the size and color of the cone, have received names of four or even
five terms--Pinus montana pumilio applanata--or Pinus montana uncinata
rostrata castanea etc., etc. These elaborations may be seen in the
Tharand Jahrbuch of 1861, p. 166, and with them appear also Hartig's
specifications of 60 forms of this species, each dignified with a
Latin name.

Plate XXI.

Fig. 186, Cone of var. uncinata. Figs. 187, 188, Cones. Fig. 189,
Leaf-fascicles, magnified leaf-section and more magnified dermal
tissues of the leaf. Fig. 190, Tree and dwarf-form of the Pyrenees.

31. PINUS LUCHUENSIS

1894 P. luchuensis Mayr in Bot. Centralbl. lviii. 149, f.

Spring-shoots uninodal. Bark-formation late, the upper trunk covered with a smooth cortex. Leaves binate, from 12 to 16 cm. long, the epiderm thick, hypoderm of two or three rows of cells; resin-ducts medial or with an occasional external duct. Conelets mucronate toward the apex. Cones from 3 to 6 cm. long, ovate-conic, symmetrical; apophyses lustrous nut-brown, transversely carinate, the umbo unarmed.

This Pine is known to me through Mayr's description and a single dried
specimen. The smooth cortex of young trees distinguishes it from all
other east-Asiatic Hard Pines. Mayr includes under this species the
Pine of Hong Kong. But in this he must be mistaken, for there is no
species yet found in China that agrees with the description of P.
luchuensis.

Plate XXII.

Fig. 191, Cone. Fig. 192, Leaf-fascicle and magnified leaf-section.

32. PINUS THUNBERGII

1784 P. sylvestris Thunberg, Fl. Jap. 274 (not Linnaeus).
1842 P. Massoniana Siebold & Zuccarini. Fl. Jap. ii. 24, t. 113
(not Lambert).
1868 P. Thunbergii Parlatore in DC. Prodr. xvi-2, 388.

Spring-shoots uninodal. Buds of leading-shoots white and conspicuous. Leaves binate, from 6 to 11 cm. long, the epiderm thick, hypoderm strong, resin-ducts medial. Conelets with short-mucronate scales. Cones from 4 to 6 cm. long, ovate or ovate-conic, symmetrical; apophyses nut-brown, flat or convex and transversely carinate, the prickle of the umbo more or less persistent.

The Black Pine of Japan has been cultivated for centuries, and by
skillful Japanese gardeners has been trained into dwarf and other
curious forms. It is hardy in cold-temperate climates. It is distinct
from P. densiflora by the medial ducts of its leaf, from P. nigra by
the fewer, larger, brown scales of its cone, and from P. resinosa by
the armature of its conelet. It appears in most determinations of
Chinese collections, but there is no Chinese Pine with the white buds
and the medial leaf-ducts of this species.

Plate XXII.

Fig. 196, Two cones. Fig. 197, Leaf-fascicle and magnified
leaf-section.

33. PINUS NIGRA

1785 P. nigra Arnold, Reise n. Mariaz. 8, t.
1804 P. laricio Poiret in Lamarck, Encycl. Meth. v. 339.
1808 P. halepensis Bieberstein, Fl. Taur. Cauc. ii. 408 (not Miller).
1809 P. pinaster Besser, Fl. Galic. ii. 294 (not Aiton).
1813 P. maritima Aiton, f. Hort. Kew. v. 315 (not Lambert).
1816 P. sylvestris Baumgarten, Stirp. Transsilv. ii. 304
(not Linnaeus).
1818 P. pyrenaica Lapeyrouse, Hist. Pl. Pyren. Suppl. 146.
1824 P. Pallasiana Lambert, Gen. Pin. ii. 1, t. 1.
1825 P. austriaca Hoess in Flora, viii-1, Beil. 113.
1831 P. nigricans Host, Fl. Austr. ii. 628.
1842 P. dalmatica Visiani, Fl. Dalmal. 199, note.
1851 P. Salzmanni Dunal in Mem. Acad. Montp. ii. 82, tt.
1863 P. Heldreichii Christ in Verh. Nat. Ges. Basel, iii. 549.
1864 P. leucodermis Antoine in Oesterr. Bot. Zeitschr. xiv. 366.
1896 P. pindica Formanek in Verh. Nat. Ver. Bruenn, xxxiv. 272.

Spring-shoots uninodal. Leaves binate, from 9 to 16 cm. long, the epiderm thick, hypoderm conspicuous, resin-ducts medial. Conelets mucronate. Cones from 4 to 8 cm. long, subsessile, symmetrical; apophyses lustrous, tawny yellow, transversely carinate, the keel strongly convex, the mucro of the umbo more or less persistent.

A valuable tree unequally distributed over the mountain slopes of
central and southern Europe and Asia Minor. The typical form, under
the name of the Austrian Pine, is a familiar exotic of the Middle and
Eastern States of America. As Mathieu states (Flore Forest., ed. 4,
597), this species is quite constant in cone and bark. It may be added
that the anatomy of the leaf is also constant, while the dimensions of
both leaf and cone present no unusual variations. The varieties
generally accepted are founded on the habit of the tree, a character
of forestal or horticultural rather than of botanical importance.

Plate XXII.

Fig. 193, Two cones. Fig. 194, Leaf-fascicle and magnified
leaf-section. Fig. 195, Magnified dermal tissues of the leaf.

34. PINUS MERKUSII

1790 P. sylvestris Loureiro, Fl. Cochinch. ii. 579 (not Linnaeus).
1845 P. Merkusii De Vriese, Pl. Nov. Ind. Bat. 5, t. 2.
1847 P. Finlaysoniana Wallich ex Blume, Rumphia, iii. 210.
1849 P. Latteri Mason in Jour. Asiat. Soc. i. 74.

Spring-shoots uninodal. Leaves binate, slender, from 15 to 20 cm. long, the hypoderm of uniform thick-walled cells, resin-ducts medial, or with internal or septal ducts, endoderm-cells very unequal in size, some of them large. Conelets unarmed. Cones from 5 to 8 cm. long, peculiarly narrow-cylindrical, symmetrical; apophyses lustrous, rufous brown, radially carinate, the transverse keel prominent.

Of the habit of this Pine I know nothing. As a species it is very
clearly defined by its peculiar cone and leaf-section. It grows in the
Philippines, Sumatra, Lower Burmah and western Indo-China. In my
specimen the pits of the ray-cells of the wood are both large and
small. In this particular it may belong in either of two groups of
species. Its uniform leaf-hypoderm associates it with this group or
with P. halepensis of the Insignes. I have assumed the cone to be
dehiscent at maturity and have placed it with the Lariciones, but if
further information shows the cone to be serotinous, this species
should be transferred to the serotinous group.

Plate XXIII.

Fig. 198, Cone. Fig. 199, Magnified sections of two leaves. Fig.
200, Leaf-fascicle.

35. PINUS SINENSIS

1832 P. sinensis Lambert, Gen. Pin. ed. 8vo. i. 47, t. 29.
1867 P. tabulaeformis Carriere, Trait. Conif. ed. 2, 510.
1881 P. leucosperma Maximowicz in Bull. Acad. St. Petersb. xxvii. 558.
1899 P. yunnanensis Franchet in Jour. de Bot. xiii. 253.
1901 P. funebris Komarow in Act. Hort. Petrop. xx. 177.
1902 P. Henryi Masters in Jour. Linn. Soc. xxvi. 550.
1906 P. densata Masters in Jour. Linn. Soc. xxxvii. 416.
1906 P. prominens Masters in Jour. Linn. Soc. xxxvii. 417.
1911 P. Wilsonii Shaw in Sargent, Pl. Wilson. i. 3.

Spring-shoots uninodal, pruinose. Leaves binate, ternate, or both, from 10 to 15 cm. long, stout and rigid; resin-ducts external, or external and medial. Staminate catkins in short capitate clusters. Conelets mucronate. Cones from 4 to 9 cm. long, ovate, symmetrical or oblique, tenaciously persistent, dehiscent at maturity; apophyses lustrous, pale tawny yellow at first, gradually changing to a dark nut-brown, tumid, the posterior scales often larger and more prominent.

A tree of cold-temperate and subalpine levels, growing on the
mountains of central and western China, and at lower altitudes in the
north and in Corea. It is recognized by its tenaciously persistent
cones with a remarkable change in color. It is constantly confused
with P. Thunbergii and P. densiflora, neither of which grows
spontaneously in China. From the former it differs in leaf-section and
bud (the bud of P. sinensis is never white), from the latter in the
lustre and the color variation of its cone, and from both in the
frequent obliquity of its cone and in the frequent presence of
trimerous leaf-fascicles.

Of the two varieties of this species, densata and yunnanensis (Shaw in
Sargent, Pl. Wilson. ii. 17), the former represents the extreme
oblique form of cone, the latter represents the longest dimensions of
cone and leaf. The effect of environment on this species can be seen
in figs. 202, 203, from a lower slope and rich soil, and fig. 204,
from a high rocky ledge in the same locality.

Plate XXIII.

Fig. 201, Cone of var. densata. Fig. 202, Cone of var. yunnanensis.
Fig. 203, Leaf-fascicle and magnified leaf-section of var.
yunnanensis. Fig. 204, Cone and leaf-fascicle from a rocky ledge.
Fig. 205, Cone, leaf-fascicle and magnified leaf-section of the
typical form. Fig. 206, Seeds. Fig. 207, Conelet and its enlarged
scale.

36. PINUS INSULARIS

1837 P. taeda Blanco, Fl. Filip. 767 (not Linnaeus).
1847 P. insularis Endlicher, Syn. Conif. 157.
1854 P. khasiana Griffith, Notul. Pl. Asiat. iv. 18; Icon. Pl.
Asiat. tt. 367, 368.
1868 P. kasya Royle ex Parlatore in DC. Prodr. xvi-2, 390.

Spring-shoots uninodal, glabrous. Leaves from 12 to 24 cm. long, in fascicles of 3, rarely of 2, very slender; resin-ducts external, rarely with a medial duct. Conelets mucronate. Cones from 5 to 10 cm. long, ovate-conic, symmetrical or oblique, tenaciously persistent; apophyses lustrous, nut-brown, convex or elevated along a transverse keel, the posterior scales of some cones larger and more prominent than the anterior scales, the mucro usually deciduous.

A species of the Philippines and of northern Burmah. In both countries
it is locally exploited for wood and resin. It differs from the common
form of P. sinensis by its much longer leaves, and from its var.
yunnanensis, which it more resembles, by its much more slender and
pliant leaves. Moreover its cone, so far as I can learn, is not yellow
at maturity, but brown.

Plate XXIII.

Figs. 208, 209, Three cones. Fig. 210, Leaf-fascicle and magnified
leaf-section.

=XI. AUSTRALES=

Pits of the ray-cells small. Leaf-hypoderm biform or variable. Spring-shoots uninodal in some, multinodal in other species. Cones dehiscent at maturity.

This group combines the dehiscent cone of the Lariciones with the
wood-anatomy of the serotinous Pines. Also the multinodal spring-shoot
first appears here and is gradually developed among the species,
absent in Nos. 37-39, sometimes present in Nos. 40-43, and prevalent
in Nos. 44-47.

All the species are of the Western Hemisphere, and among them may be
found the biform hypoderm of the leaf, the internal resin-duct, and
the total absence of external resin-ducts, characters common in
American Hard Pines. The eastern species are quite constant in their
characters and present no varietal forms; the western species, on the
other hand, are very variable. This difference may be due to the even
level and slight climatic differences of the Atlantic states and to
the remarkable diversity of altitude and climate of the western states
and Mexico.

Outer walls of the leaf-endoderm thick.
Cones large, attaining 12 cm. or more in length.
Prickles of the cone inconspicuous.
Bark-formation late 37. pseudostrobus
Bark-formation early 38. Montezumae
Prickle of the cone conspicuous 39. ponderosa
Cones small, 7 cm. or less in length 40. teocote
Outer walls of the leaf-endoderm thin.
Spring-shoots mostly uninodal.
Prickle of the cone slender, sometimes deciduous.
Cones mostly oblique 41. Lawsonii
Cones symmetrical 42. occidentalis
Prickles of the cone stout and persistent 43. palustris
Spring-shoots multinodal.
Resin-ducts internal 44. caribaea.
Resin-ducts mostly medial.
Prickle of the cone stout 45. taeda
Prickle of the cone slender.
Bark-formation late 46. glabra
Bark-formation early 47. echinata

37. PINUS PSEUDOSTROBUS

1839 P. pseudostrobus Lindley in Bot. Reg. xxv. Misc. 63.
1839 P. apulcensis Lindley in Bot. Reg. xxv. Misc. 63.
1842 P. tenuifolia Bentham, Pl. Hartw. 92.
1846 P. orizabae Gordon in Jour. Hort. Soc. Lond. i. 237, f.

Spring-shoots uninodal, conspicuously pruinose. Bark-formation late, the cortex of young trees smooth. Leaves in fascicles of 5, sometimes of 6, from 15 to 30 cm. long, drooping; resin-ducts medial, hypoderm variable in amount, often in very large masses, the outer walls of the endoderm thick. Conelets mucronate. Cones from 7 to 14 cm. long, ovate or ovate-conic, symmetrical or oblique, deciduous and often leaving a few basal scales on the trees; apophyses rufous or fulvous brown, flat, elevated or, in one variety, prolonged in various degrees, the prolongations nearly uniform or much more prominent on the posterior face of the cone, the mucro usually deciduous.

A species of the subtropical and warm-temperate altitudes of Mexico
and Central America. Its range includes both eastern and western
slopes of the northern plateau. Its northern limit is in Nuevo Leon,
and it probably reaches in Nicaragua the southern limit of pines in
the Western Hemisphere. It is distinguished from all its associates by
the smooth gray trunk of the young trees, by their long internodes,
and by their drooping gray-green foliage.

Some cones of this species develop protuberances of all degrees of
prominence up to the curious cone collected in Oaxaca by Nelson (var.
apulcensis, Shaw, Pines Mex. t. 12, fig. 8). There is also a
remarkable difference in the amount of leaf-hypoderm. On many trees of
the western part of the range this tissue forms septa across the green
mesophyll. Such partitions are sometimes met in other species, P.
Pringlei or P. canariensis, where the hypoderm is abundant. But in P.
pseudostrobus they appear in some leaves of weak, as well as of strong
hypoderm (var. tenuifolia, Shaw, Pines Mex. t. 13, ff. 2, 4, 5, 7, 8).

Plate XXIV.

Fig. 211, Cone. Fig. 212, Two cones of var. tenuifolia. Figs. 213,
214, Two cones of var. apulcensis. Fig. 215, Magnified section of 3
leaves of var. tenuifolia. Fig. 216, Magnified section of 2 leaves
of the species. Fig. 217, Bud destined to produce staminate flowers.
Fig. 218, Ten-year old branch showing smooth cortex. Fig. 219, Young
and mature trees in open growth.

38. PINUS MONTEZUMAE

1817 P. occidentalis H. B. & K. Nov. Gen. ii. 4 (not Swartz).
1832 P. Montezumae Lambert, Gen. Pin. ed. 8vo, i. 39, t. 22.
1839 P. Devoniana Lindley in Bot. Reg. xxv. Misc. 62.
1839 P. Hartwegii Lindley in Bot. Reg. xxv. Misc. 62.
1839 P. Russelliana Lindley in Bot. Reg. xxv. Misc. 63.
1839 P. macrophylla Lindley in Bot. Reg. xxv. Misc. 63.
1840 P. filifolia Lindley in Bot. Reg. xxvi. Misc. 61.
1841 P. Sinclairii Hooker & Arnott, Bot. Beechy Voy. 392, t. 93
(as to cone).
1841 P. radiata Hooker & Arnott, Bot. Beechy Voy. 443 (as to leaves).
1847 P. Grenvilleae Gordon in Jour. Hort. Soc. Lond. ii. 77, f.
1847 P. Gordoniana Hartweg in Jour. Hort. Soc. Lond. ii. 79, f.
1847 P. Wincesteriana Gordon in Jour. Hort. Soc. Lond. ii. 158, f.
1847 P. rudis Endlicher, Syn. Conif. 151.
1847 P. Ehrenbergii Endlicher, Syn. Conif. 151.
1858 P. Lindleyana Gordon, Pinet. 229.
1891 P. Donnell-Smithii Masters in Bot. Gaz. xvi. 199.

Spring-shoots uninodal, slightly or not at all pruinose. Bark-formation early, the branches becoming dark and rough. Leaves prevalently in fascicles of 5, but varying from 3 to 8, extremely variable in length, attaining 45 cm. at subtropical levels; resin-ducts medial, hypoderm sometimes uniform, more commonly multiform, the outer walls of the endoderm thick. Conelet mucronate, the prickle often reflexed. Cones of many sizes, attaining in warm localities 30 cm. in length, ovate-conic or long-conic, symmetrical, often curved, deciduous and often leaving a few scales on the tree; apophyses dull, rarely lustrous, nut-brown, or of various shades of fuscous brown to nearly black, flat, tumid, pyramidal or sometimes slightly protuberant, the prickle rarely persistent.

This species ranges from the mountains of northern Durango to the
volcanoes of Guatemala, or possibly farther south. It is found at all
altitudes where Pines can grow except on the tropical levels of
Guatemala. Its more hardy forms have been successfully grown in the
milder parts of Great Britain and northern Italy. It is felled for
lumber in many parts of Mexico.

This sturdy Pine and its numberless variations present the most
remarkable example of adaptation in the genus. The variations are
mostly those associated with changes of environment--dimensions of
cone and leaf and the number of leaves in the fascicle. These are so
accurately correlated with altitude and exposure, and are so
imperceptibly graded, that no specific segregations among them have
yet been successfully established.

The type-specimen figured by Lambert does not show the longest cone
and leaf of this species. They are better represented by specimens
which have been named P. filifolia. Such dimensions prevail in
subtropical localities. At temperate altitudes these dimensions are
much reduced, but here are found a longer form of cone and leaf (var.
Lindleyi, Loudon) and a shorter form (var. rudis, Shaw). At still
higher altitudes and up to the timber-limit the var. Hartwegii,
Engelmann, with short leaves and a small nearly black cone is found.
Among these varieties there is no such sharp distinction as these
definitions imply. All dimensions of fruit and foliage and the various
brown and black shades of the cone blend into each other through
endless intergradations. A monograph of this species, by one who could
devote some years to it on the superb volcanoes and in the delightful
climates where this tree abounds, would be a valuable contribution to
science.

Plate XXV. (Cones and leaves much reduced.)

Fig. 220, Cone and leaves of Lambert's plate. Figs. 221, 222, Longer
cones and leaves of the species. Fig. 223, Cone and leaves of var.
Lindleyi. Fig. 224, Cones and leaves of var. rudis. Fig. 225, Cone
and leaves of var. Hartwegii. Fig. 226, Magnified leaf-sections.
Figs. 227, 228, Two forms of the dermal tissues of the leaf,
magnified. Fig. 229, Habit of the tree.

39. PINUS PONDEROSA

1836 P. ponderosa Douglas ex Lawson's Agric. Man. 354.
1847 P. Benthamiana Hartweg in Jour. Hort. Soc. Lond. ii. 189.
1848 P. brachyptera Engelmann in Wislizenus, Tour Mex. 89.
1848 P. macrophylla Engelmann in Wislizenus, Tour Mex. 103
(not Lindley).
1853 P. Jeffreyi Balfour in Bot. Exp. Oregon, 2, f.
1854 P. Engelmanni Carriere in Rev. Hort. 227.
1855 P. Beardsleyi Murray in Edinb. Phil. Jour. ser. 2, i. 286, t. 6.
1855 P. Craigana Murray in Edinb. Phil. Jour. ser. 2, i. 288, t. 7.
1858 P. Parryana Gordon, Pinet. 202 (not Engelmann).
1859 P. deflexa Torrey in Emory's Rep. ii. 1, 209, t. 56.
1878 P. arizonica Engelmann in Wheeler's Rep. vi. 260.
1889 P. latifolia Sargent in Gar. & For. ii. 496, f. 135.
1894 P. apacheca Lemmon in Erythea, ii. 103, t. 3.
1897 P. Mayriana Sudworth in Bull. 14, U. S. Dept. Agric. 21.
1897 P. scopulorum Lemmon in Gar. & For. x. 183.
1900 P. peninsularis Lemmon, W. Am. Conebear. 114.

Spring-shoots uninodal, sometimes pruinose. Bark-formation early. Leaves prevalently in fascicles of 3, but varying from 2 to 5 or more, from 12 to 36 cm. long; resin-ducts medial, hypoderm uniform or multiform, outer walls of the endoderm thick. Conelet mucronate, the mucro often reflexed. Cones from 8 to 20 cm. long, ovate-conic, symmetrical, deciduous and usually leaving a few basal scales on the tree; apophyses tawny yellow to fuscous brown, lustrous, elevated along a transverse keel, sometimes protuberant and reflexed, the umbo salient and forming the base of a pungent, persistent prickle.

This species ranges from southern British Columbia over the mountains
between the Pacific and the eastern foot-hills of the Rocky Mountains,
including the Black Hills of South Dakota, to the northeastern Sierras
of Mexico, to northern Jalisco and Lower California, forming, in many
localities, large forests and furnishing the best Hard Pine timber of
the western United States. It attains its best growth on the Sierras
of California and is, next to P. Lambertiana, the tallest of the
Pines.

Like P. Montezumae, and under like influences, it shows much
dimensional variation, and the leaf-fascicles are heteromerous, with
the larger number in the southern part of its range. Many authors
consider the variety Jeffreyi Vasey to be a distinct species; but
here, it seems to me, too much importance is attached to the pruinose
branchlet, clearly a provision against transpiration and associated
rather with a dry environment than with a species. Most observers
discover many intermediate forms between this variety and the species.
The var. scopulorum Engelm. is the Rocky Mountain form with leaves in
2's and 3's and with small cones passing into P. arizonica, Engelm., a
more southern form with small cones and leaves in fascicles of 3 to 5.
The var. macrophylla (Shaw, Pines Mex. 24), in addition to its long
and stout leaves, bears a cone with protuberant apophyses, somewhat
comparable to the intermediate forms of P. pseudostrobus var.
apulcensis Shaw (l. c.). Fascicles of 6 and 7 leaves are sometimes
found, and specimens that I have collected in Sandia, Durango (issued
by Pringle, through a misunderstanding, under the name P. Roseana,
ined.) show such fascicles on the fertile branches.

Plate XXVI.

Fig. 230, Cone and seed of var. Jeffreyi. Fig. 231, Cone of var.
macrophylla. Fig. 232, Cone of var. scopulorum. Fig. 233, Magnified
leaf-section and cells of leaf-endoderm. Fig. 234, Magnified dermal
tissues of the leaf, showing uniform and multiform hypoderm.

40. PINUS TEOCOTE

1830 P. teocote Schlechtendal & Chamisso in Linnaea, v. 76.

Spring-shoots uninodal, or sometimes multinodal. Leaves prevalently in fascicles of 3, but varying from 3 to 5, from 10 to 20 cm. long; resin-ducts medial, sometimes with an internal duct, hypoderm biform, endoderm with thick outer walls. Conelets mucronate. Cones usually very small, from 4 to 6 cm. long, but with a larger varietal form, ovate to long-conic, symmetrical; apophyses nut-brown, flat or tumid, the mucro usually deciduous.

This species grows at temperate altitudes from Chiapas to Nuevo Leon,
associated with temperate Mexican species such as P. patula, P.
leiophylla and others, and is easily recognized by its small cone. The
variety with a larger cone (var. macrocarpa, Shaw, Pines Mex. t. 10) I
have found growing in mixed groves of P. teocote and P. leiophylla. It
resembles the latter in cone and leaf, but lacks the peculiar
character that distinguishes P. leiophylla from all other Mexican
species--the triennial cone. Some of the specimens of Hartweg No. 441
belong here, as well as Pringle's specimens, Nos. 10013, 10018,
distributed as P. eslavae, ined.

Plate XXVII.

Fig. 235, Two cones of the species and the larger cone of the
variety. Fig. 236, Leaf-fascicle and magnified sections of two
leaves. Fig. 237 a, Dermal tissues of the leaf magnified; b,
magnified cells of the leaf-endoderm. Fig. 238, Habit of the tree.

41. PINUS LAWSONII

1862 P. Lawsonii Roezl ex Gordon, Pinet. Suppl. 64.
1905 P. Altamirani Shaw in Sargent, Trees & Shrubs, i. 209, t. 99.

Spring-shoots conspicuously pruinose, uninodal or not infrequently multinodal. Leaves in fascicles of 3, 4 or 5, not exceeding 24 cm. in length; resin-ducts internal, often with one or two medial ducts, hypoderm biform, endoderm usually with thin outer walls. Conelets mucronate. Cones from 5 to 7 cm. long on pliant peduncles, ovate or ovate-conic, oblique or sometimes symmetrical, deciduous, or persistent with a weak hold on the branch; apophyses nut-brown, flat or tumid, often protuberant on the posterior face of the cone, the umbo usually large and salient, forming a rounded button-like projection, on which the mucro is wanting.

A subtropical species of central and western Mexico, growing alone or
associated with P. oocarpa, P. Pringlei and the subtropical forms of
P. Montezumae and P. pseudostrobus. It is recognized among its
associate species by its conspicuously glaucous foliage. The cone is
very variable on trees of the same grove, both in size and in the
protuberance of its apophyses. Gordon's specimen in the Kew herbarium
consists of a single detached cone and a few leaves. The leaves differ
from all that I have examined in showing thick-walled endoderm cells,
but the cone corresponds with many of my own collection.

Plate XXVII.

Fig. 239, Three cones. Fig. 240, Leaf-fascicle and magnified
leaf-section. Fig. 241, Magnified cells of the leaf-endoderm.

42. PINUS OCCIDENTALIS

1788 P. occidentalis Swartz, Nov. Gen. & Sp. Pl. 103.
1862 P. cubensis Grisebach in Mem. Am. Acad. ser. 2, viii. 530.
1880 P. Wrightii Engelmann in Trans. Acad. Sci. St. Louis, iv. 185.

Spring-shoots uninodal, pruinose. Leaves in fascicles of 2 to 5, from 15 to 22 cm. long; resin-ducts internal, hypoderm biform, endoderm with thin outer walls. Conelets erect, aristate. Cones from 5 to 8 cm. long, reflexed, ovate, symmetrical, deciduous; apophyses nut-brown, lustrous, flat or tumid, the umbo often thin and, together with the slender prickle, bent sharply downward.

This species is confined to San Domingo, Hayti and eastern Cuba. Its
erect conelet and reflexed cone distinguish it from P. caribaea, which
has both its conelet and cone reflexed. Moreover the conelet is
usually, perhaps always, subterminal in P. occidentalis.

Plate XXVIII.

Fig. 247, Cone. Fig. 248, Conelet and enlarged aristate scales. Fig.
249, Magnified sections of two leaves and more magnified dermal
tissues.

43. PINUS PALUSTRIS

1768 P. palustris Miller, Gard. Dict. ed. 8.
1810 P. australis Michaux f. Hist. Arbr. Am. i. 64, t. 6.

Spring-shoots uninodal, rarely multinodal. Buds peculiarly large, white, and conspicuously fringed with the long free cilia of the bud-scales. Leaves in fascicles of 3, from 20 to 45 cm. long, rigid; resin-ducts internal, hypoderm biform, endoderm with thin outer walls. Conelets short-mucronate. Cones from 15 to 20 cm. long, narrow, tapering from a rounded base to a blunt point, symmetrical, deciduous and usually leaving a few scales on the tree; apophyses dull nut-brown, elevated along a transverse keel, the umbo salient and forming the broad base of a small persistent prickle.

Its thin sap-wood, its very strong heavy wood of large dimensions with
abundant resin of excellent quality make this the most valuable
species of the genus. It ranges over the sandy plain that borders the
Atlantic and the Gulf of Mexico, from southeastern Virginia to eastern
Texas. The northern limit is approximately the centre of the Southern
and Gulf States, with a northern extension in Alabama to the base of
the Appalachian Mountains and to northwestern Louisiana. Its southern
limit lies near the centre of the Florida peninsula.

Among its associates this species is recognized by its large white
fringed bud and its elongated cone. Its leaves attain, on vigorous
trees, the maximum length among Pines, but on most trees the leaves do
not differ in length from the longer forms of those of P. caribaea or
P. taeda. A peculiarity, which it shares with P. caribaea, is the
deciduous scaly bark of mature trees, constantly falling away in thin
irregular scales.

Plate XXVIII.

Figs. 242, 243, Cones and seed. Fig. 244, Bud. Fig. 245, Magnified
leaf-section. Fig. 246, Magnified cells of the leaf-endoderm. The
dermal tissues of fig. 249 also apply to this species.

44. PINUS CARIBAEA

1851 P. caribaea Morelet in Rev. Hort. Cote d'Or, i. 105.
1864 P. bahamensis Grisebach, Fl. Brit. W. Ind. 503.
1880 P. Elliottii Engelmann in Trans. Acad. St. Louis, iv. 186,
tt. 1-3.
1884 P. cubensis Sargent in Rep. 10th. Cens. U. S. ix. 202
(not Grisebach).
1893 P. heterophylla Sudworth in Bull. Torrey Bot. Club, xx. 45.
1903 P. recurvata Rowley in Bull. Torrey Bot. Club, xxx. 107.

Spring-shoots multinodal, more or less pruinose. Buds pale chestnut-brown. Leaves in fascicles of 2 and 3, or more in its southern range, from 12 to 25 cm. long; resin-ducts internal, hypoderm biform, endoderm with thin outer walls. Conelets reflexed on long peduncles, mucronate. Cones from 5 to 15 cm. long, ovate or oblong-ovate, symmetrical, deciduous and leaving often a few basal scales on the branch; apophyses lustrous, rufous-brown, tumid, the umbo somewhat salient and minutely mucronate.

The northern limit of the range of P. caribaea extends from the coast
of southeastern S. Carolina through southeastern Georgia and southern
Alabama to southeastern Louisiana. It is associated with P. palustris,
taeda, serotina, echinata and glabra in this part of its range. It
continues through Florida, where it encounters P. clausa. On the
Bahamas it is the only Pine. On the Isle of Pines it finds in P.
tropicalis another associate. It also grows in Honduras and Guatemala.
The wood and resin of this species are of such excellent quality that
no commercial distinction is made between P. caribaea and P.
palustris.

Plate XXIX.

Fig. 250, Cone from the Isle of Pines. Fig. 251, Small form of cone.
Fig. 252, Large form of cone and binate leaf-fascicle. Fig. 253,
Conelet. Fig. 254, Magnified sections of leaves from binate and
ternate fascicles. Fig. 255, Habit of the tree, contrasted with a
tree of P. palustris in the middle-distance.

45. PINUS TAEDA

1753 P. taeda Linnaeus, Sp. Pl. 1000.
1788 P. lutea Walter Fl. Carol. 237.
1903 P. heterophylla Small, Fl. Southeast. U. S. 28 (not Sudworth).

Spring-shoots multinodal. Leaves in fascicles of 3, from 12 to 25 cm. long; resin-ducts medial, sometimes with an internal duct, hypoderm biform, endoderm with thin outer walls. Conelets erect, their scales prolonged into a sharp point. Cones from 6 to 10 cm. long, ovate-conic, symmetrical; apophyses dull pale nut-brown, rarely lustrous, elevated along a transverse keel, the whole umbo forming a stout triangular spine with slightly concave sides.

The species ranges from southern New Jersey to southern Arkansas,
Oklahoma, eastern Texas and southwestern Tennessee, but does not occur
in the lower half of the Florida peninsula. It is an important
timber-tree, manufactured into all descriptions of scantlings,
boarding and finish, but the wood is of various qualities. It may be
recognized by the spine of its cone in both years of growth. Excepting
the formidable armature of the cone of P. pungens, the spines are the
strongest and most persistent of all the species of eastern North
America.

Plate XXX.

Fig. 264, Cone. Fig. 265, Leaf-fascicle. Fig. 266, Magnified
leaf-section. Fig. 267. Magnified scales of the conelet.

46. PINUS GLABRA

1788 P. glabra Walter, Fl. Carol. 237.

Spring-shoots multinodal. Bark-formation late, the upper trunks of mature trees smooth. Leaves in fascicles of 2, from 9 to 12 cm. long; resin-ducts medial, hypoderm weak, sometimes of a single row, biform when of two rows, endoderm with thin outer walls. Conelets reflexed, mucronate. Cones from 4 to 7 cm. long, reflexed, ovate, symmetrical, deciduous on some trees, persistent on others; apophyses pale dull nut-brown, thin or slightly thickened, the prickle usually deciduous.

A tree that sometimes attains important dimensions, growing singly or
in small groves from the neighborhood of Charleston, S. C., to eastern
Louisiana and central Mississippi, most abundant in a strip of
territory on either side of the northern boundary of Florida. Among
the Pines of the southeastern United States it is the only species
with late bark-formation, and is therefore easily identified.

Plate XXX.

Fig. 256, Cone. Fig. 257, Enlarged scale of the conelet. Fig. 258,
Leaf-fascicle and magnified leaf-section. Fig. 259, Dermal tissues
of the leaf magnified, with a double row of hypoderm cells.

47. PINUS ECHINATA

1768 P. echinata Miller, Gard. Dict. ed. 8.
1788 P. squarrosa Walter, Fl. Carol. 237.
1803 P. mitis Michaux, Fl. Bor. Am. ii. 204.
1803 P. variabilis Lambert, Gen. Pin. i. 22, t. 15.
1854 P. Royleana Jamieson in Jour. Hort. Soc. Lond. ix. 52, f.

Spring-shoots multinodal, somewhat pruinose. Bark forming early, rough on the upper trunk. Leaves in fascicles of 2 and 3, from 7 to 12 cm. long; resin-ducts medial, with an occasional internal duct, hypoderm weak, biform when of two rows of cells, endoderm with thin outer walls. Conelets mucronate. Cones from 4 to 6 cm. long, ovate-conic, symmetrical, often persistent; apophyses dull pale nut-brown, thin or somewhat thickened along a transverse keel, the umbo salient, the mucro more or less persistent.

This species ranges from southeastern New York to northern Florida, to
West Virginia and eastern Tennessee, and through the Gulf States to
eastern Louisiana, eastern Texas, southern Missouri and southwestern
Illinois. It is extensively manufactured into material of all kinds
that enters into the construction of buildings. It differs from P.
virginiana in its longer leaves, brittle branches, and much greater
height, from P. glabra in its rough upper trunk, and from both by the
frequent presence of trimerous leaf-fascicles.

Of the six or seven pines of the southeastern United States, this
species covers a larger area and ascends the slopes of the Alleghany
Mountains far enough to meet the northern species, P. virginiana, P.
rigida, and P. strobus. Unlike the western members of this group, P.
echinata and its associates are not variable. Their characters are
singularly constant, as their limited synonymy and total lack of
varietal names attest.

Plate XXX.

Fig. 260, Cone. Fig. 261, Leaf-fascicle and magnified leaf-section
from a ternate fascicle. Fig. 262, Magnified leaf-section from a
binate fascicle. Fig. 263, Multinodal branchlet bearing lateral and
subterminal conelets and a ripe cone. Figs. 257, showing mucronate
scales of the conelet, and 259, showing dermal tissues of the leaf,
are applicable also to this species.

=XII. INSIGNES=

Pits of the ray-cells small. Cones tenaciously persistent, serotinous in various degrees. Conelets mucronate or spinose.

Spring-shoots uninodal.
Resin-ducts mostly internal 48. Pringlei
Resin-ducts mostly septal 49. oocarpa
Spring-shoots multinodal.
Cones symmetrical.
Leaf-hypoderm not biform.
Bark-formation late 50. halepensis
Bark-formation early 51. pinaster
Leaf-hypoderm biform.
Cones with slender spines.
Leaves binate.
Cones dehiscent at maturity 52. virginiana
Cones serotinous 53. clausa
Leaves ternate.
Cones dehiscent at maturity 54. rigida
Cones serotinous 55. serotina
Cones with stout spines 56. pungens
Cones oblique or unsymmetrical.
Cones and leaves very short, not exceeding 6 cm.
Cones curved or warped 57. Banksiana
Cones straight 58. contorta
Cones and leaves much longer, more than 7 cm.
Posterior cone-scales gradually larger than
anterior scales.
Bark-formation late 59. Greggii
Bark-formation early 60. patula
Posterior cone-scales abruptly larger than
anterior scales.
Cones with very stout spines 61. muricata
Cones with minute or deciduous prickles.
Bark-formation late 62. attenuata
Bark-formation early 63. radiata

48. PINUS PRINGLEI

1905 P. Pringlei Shaw in Sargent, Trees & Shrubs, i. 211, t. 100.

Spring-shoots uninodal, sometimes pruinose. Leaves ternate, from 15 to 25 cm. long; resin-ducts internal or with an occasional septal duct, hypoderm biform, in thick masses, often projecting far into the green tissue and sometimes touching the endoderm. Conelets mucronate. Cones from 5 to 10 cm. long, reflexed on a rigid peduncle, subsymmetrical or more or less oblique, tenaciously persistent, often serotinous; apophyses sublustrous tawny yellow or fulvous brown, convex, the posterior scales often more prominently developed, the mucro usually wanting; seed with a perceptibly thickened wing-blade.

A tree with long erect bright green foliage, confined, so far as
known, to the subtropical altitudes of western Mexico. As it grows in
Uruapan, Michoacan, there are two forms of the cone, large and small,
both with the same long rigid leaf.

Plate XXXI.

Figs. 268, 269. Three cones and seed. Fig. 270, Leaf-fascicle and
magnified leaf-section.

49. PINUS OOCARPA

1838 P. oocarpa Schiede in Linnaea, xii. 491.
1842 P. oocarpoides Lindley ex Loudon, Encycl. 1118.

Spring-shoots uninodal, pruinose. Leaves in fascicles of 3, 4 or 5, from 15 to 30 cm. long, erect; resin-ducts mostly septal, sometimes internal, hypoderm biform or multiform. Conelets on very long peduncles, mucronate. Cones from 4 to 10 cm. long, long-pedunculate, broad-ovate to ovate-conic, symmetrical or sometimes oblique, persistent, more or less serotinous; apophysis gray-yellow or greenish yellow of high lustre, flat or variously convex, delicately and radially carinate, the umbo often salient, the prickle usually broken away; seed-wing appreciably thickened at the base of the blade.

A subtropical species, ranging from Guatemala to the northern border
of Sinaloa in northern Mexico; remarkable for the length of the
peduncle of the cone and for the prevalence of septal resin-ducts in
the leaf.

Plate XXXI.

Fig. 271, Three cones and seed. Fig. 272, Leaf-fascicle and
magnified leaf-section. Fig. 273, Cone from northern part of the
range. Fig. 274, Leaf-fascicle and magnified leaf-section from near
the northern limit.

50. PINUS HALEPENSIS

1762 P. sylvestris Gouan, Hort. Reg. Monspel. 494 (not Linnaeus).
1768 P. halepensis Miller, Gard. Dict. ed. 8.
1803 P. maritima Lambert, Gen. Pin. i. 13, t. 10.
1812 P. resinosa Loiseleur, Nouv. Duham. v. 237, t. 77 (not Aiton).
1815 P. brutia Tenore, Cat. Hort. Neap. Appx. 1, 75.
1826 P. arabica Sieber ex Sprengel, Syst. Veg. iii. 886.
1833 P. pyrenaica David in Ann. Soc. Hort. Paris, 186
(not Lapeyrouse).
1834 P. hispanica Cook, Sketches in Spain, ii. 337.
1838 P. pityusa Steven in Bull. Soc. Nat. Mosc. xi. 49.
1841 P. carica Don in Ann. Mag. Nat. Hist. vii. 459.
1847 P. persica Strangways ex Endlicher, Syn. Conif. 157.
1855 P. abasica Carriere, Trait. Conif. 352.
1855 P. Loiseleuriana Carriere, Trait. Conif. 382.
1856 P. Parolinii Visiani in Mem. Ist. Venet. vi. 243, t. 1.
1902 P. eldarica Medwejew in Act. Hort. Tiflis. vi-2, 21, f.

Spring-shoots often multinodal. Bark-formation late, the branches ashen gray and smooth for several years. Leaves binate, from 6 to 15 cm. long; resin-ducts external, hypoderm uniform. Conelets obscurely mucronate near the apex. Cones from 8 to 12 cm. long, ovate-conic, symmetrical or subsymmetrical, persistent, often serotinous; apophyses red with a lighter or deeper brownish shade, lustrous, flat, convex or low-pyramidal, radially carinate, the umbo often ashen gray and unarmed.

A tree ranging from Portugal to Afghanistan, and from Algeria to
Dalmatia and to northern Italy and Southern France. It is a vigorous
species in its own home, growing readily in poor soils, but not
successful in colder climates. The wood is resinous and valuable for
fuel. The turpentine industry, once associated with this species, has
gradually been abandoned for the more copious product of P. pinaster.

It is recognized by its lustrous red cones and by the ashen gray
cortex of its branches and upper trunk. Tenore's P. brutia (pyrenaica
of some authors) is founded on a difference in the length of the leaf
and on an erect cone with a shorter peduncle. To recognize species on
such distinctions would not be consistent with the purpose and spirit
of this discussion.

Plate XXXII.

Fig. 279, Two cones. Fig. 280, Cone. Fig. 281, Lateral conelet. Fig.
282, Magnified leaf-section. Fig. 283, Dermal tissues of the leaf
magnified.

51. PINUS PINASTER

1768 P. sylvestris Miller, Gard. Dict. ed. 8 (not Linnaeus).
1789 P. pinaster Aiton, Hort. Kew. iii. 367.
1798 P. laricio Savi, Fl. Pisa. ii. 353 (not Poiret).
1804 P. maritima Poiret in Lamarck, Encycl. Meth. v. 337
(not Lambert).
1826 P. escarena Risso, Hist. Nat. ii. 340.
1835 P. Lemoniana Bentham in Trans. Hort. Soc. Lond. ser. 2,
i. 512, t.
1845 P. Hamiltonii Tenore, Cat. Ort. Nap. 90.

Spring-shoots sometimes multinodal. Bark-formation early. Leaves binate, from 10 to 20 cm. long, stout and rigid; resin-ducts medial, hypoderm multiform, the inner cells gradually larger, remarkably large in the angles of the leaf. Conelets minutely mucronate. Cones from 9 to 18 cm. long, nearly sessile, ovate-conic, symmetrical or subsymmetrical, persistent, sometimes serotinous; apophyses lustrous nut-brown or rufous brown, conspicuously pyramidal, the umbo salient and pungent.

A maritime tree corresponding nearly, in its range, with the preceding
species, but more hardy in cooler climates. It grows from Portugal to
Greece, and from Algeria to Dalmatia, but its area has been much
extended by cultivation. Under favorable conditions it attains large
dimensions, but its exploitation for resin and turpentine tends to
diminish its size and disfigure its habit (Mathieu, Fl. Forest, ed. 4,
611). Its rapid growth, strong root-system, and its ability to thrive
on poor sandy soil, have led to the employment of this species for the
forestation of sand-dunes in France.

The tree can be recognized by its long stout leaves and persistent
brown cones. Its leaf-section is peculiar in the remarkable size of
the inner cells of the hypoderm, especially in the angles of the leaf.

Plate XXXII.

Figs. 275, 276, Cones. Fig. 277, Magnified leaf-section. Fig. 278,
Magnified dermal tissues in the angle of the leaf.

52. PINUS VIRGINIANA

1768 P. virginiana Miller, Gard. Dict. ed. 8.
1789 P. inops Aiton, Hort. Kew. iii. 367.

Spring-shoots multinodal, pruinose; branchlets pliant and tough. Bark-formation slow, the cortex not rifted for some years. Leaves binate, from 4 to 8 cm. long; resin-ducts medial, or with an occasional internal duct; hypoderm biform. Conelets with long tapering sharp scales. Cones from 4 to 6 cm. long, ovate or oblong-ovate, symmetrical, persistent, dehiscent at maturity; apophyses lustrous nut-brown, somewhat elevated along a transverse keel, the umbo salient, forming a long slender prickle with a broad base.

Western Long Island to central Georgia and north Alabama, and from
eastern Tennessee to southern Indiana and southeastern Ohio. It is a
low bushy tree in the north, but in the south and west it attains
small timber-size and is locally exploited. It is hardy beyond the
limits of its natural range, growing readily in the vicinity of
Boston. Its short binate leaves, the persistent long prickles of its
cone, and its tough branches, combine to distinguish this Pine from
its associates. The obvious relationship of P. virginiana and P.
clausa places the former in this, rather than in the preceding group.

Plate XXXIII.

Fig. 284, Cones. Fig. 285, Conelet and its enlarged spinose scale.
Fig. 286, Leaf-fascicle, magnified leaf-section and more magnified
dermal tissues of the leaf. Fig. 287, Buds.

53. PINUS CLAUSA

1884 P. clausa Vasey ex Sargent, Rep. 10th Cens. U. S. ix. 199.

Spring-shoots multinodal. Bark-formation slow, as in the preceding species. Leaves binate, from 5 to 9 cm. long; resin-ducts medial, or with an occasional internal duct, hypoderm biform when of two rows of cells. Conelets with long tapering acute scales. Cones from 5 to 8 cm. long, reflexed, ovate-conic, symmetrical, persistent, often serotinous; apophyses lustrous nut-brown, elevated along a transverse keel, the umbo forming a triangular persistent spine.

A species of limited range, confined to the sandy coast of Alabama and
to Florida. It sometimes attains timber-size, but is usually a low
spreading tree of no commercial importance and never seen in
cultivation. It is recognized by its smooth branches, binate leaves
and numerous, often multiserial, clusters of persistent, often closed,
cones. It is associated with P. caribaea and, in the northern part of
its range, it grows with the other Southern species. By its close
resemblance it may be considered the serotinous form of P. virginiana.

Plate XXXIII.

Fig. 288, Three nodal groups of cones of the same year. Fig. 289,
Conelet and its enlarged scale. Fig. 290, Leaf-fascicle and
magnified leaf-section. Fig. 291, Larger form of the tree.

54. PINUS RIGIDA

1768 P. rigida Miller, Gard. Dict. ed. 8.
1909 P. serotina Long, in Bartonia, ii. 17 (not Michaux).

Spring-shoots multinodal. Leaves ternate, from 7 to 14 cm. long; resin-ducts medial, or with an occasional internal duct, hypoderm biform. Scales of the conelet abruptly prolonged into a spine. Cones from 3 to 7 cm. long, ovate-conic, symmetrical, persistent, dehiscent at maturity or rarely serotinous; apophyses lustrous tawny yellow, elevated along a transverse keel, the umbo salient and forming the broad base of a slender sharp prickle.

A tree with bright green foliage in spreading tufts. The northern
limit of its range is in southwestern New Brunswick, southern Maine,
central New Hampshire and Vermont, the Thousand Islands of the St.
Lawrence River and central Ohio. It ranges into Pennsylvania and
Delaware at low levels and thence over the Alleghanies into northern
Georgia. It is associated with P. strobus and P. resinosa and, further
south, with P. virginiana. The cones are rarely serotinous, but it is
remarkably like P. serotina in many characters, and is therefore
placed in this group.

Plate XXXIV.

Fig. 292, Cones. Fig. 293, Leaf-fascicle, magnified section through
a fascicle, and magnified dermal tissues of the leaf. Fig. 294,
Upper part of a tree.

55. PINUS SEROTINA

1803 P. serotina Michaux, Fl. Bor. Am. ii. 205.

Spring-shoots multinodal. Leaves ternate, from 12 to 20 cm. long; resin-ducts medial or medial and internal, hypoderm biform. Conelet long-mucronate. Cones from 5 to 7 cm. long, subglobose or short-ovate, symmetrical, persistent, serotinous; apophyses lustrous tawny yellow, slightly elevated along a transverse keel, the umbo forming the broad base of a slender, rather fragile prickle.