PART II
CLASSIFICATION OF THE SPECIES
The following classification is based on the gradual evolution of the fruit from a cone symmetrical in form, parenchymatous in tissue, indehiscent and deciduous at maturity, releasing its wingless seed by disintegration—to a cone oblique in form, very strong and durable in tissue, persistent on the tree, intermittently dehiscent, releasing its winged seeds partly at maturity, partly at indefinite intervals during several years. This evolution embraces two extreme forms of fruit, one the most primitive, the other the most elaborate, among Conifers.
Two sections of the genus, Soft and Hard Pines, are distinguished by several correlated characters, and moreover are distinct by obvious differences in the tissues of their cones as well as in the quality and appearance of their wood.
With the Soft Pines the species group naturally under two subsections on the position of the umbo, the anatomy of the wood and the armature of the conelet. In one subsection (Cembra) are found three species, P. cembra and its allies, with the cone-tissues so completely parenchymatous that the cones cannot release the seeds except by disintegration. In both subsections there is a gradual evolution from a wingless nut to one with an effective wing, adnate in one subsection, adnate and articulate in the other. The different stages of this evolution are so distinct that the Soft Pines are easily separated into definite groups.
Among the Hard Pines a few species show characters that are peculiar to the Soft Pines. These exceptional species form a subsection (Parapinaster) by themselves.
With the remaining species, the majority of the Pines, the distinctions that obtain among Soft Pines have disappeared. The dorsal umbo, the articulate seed-wing, the persistent fascicle-sheath, the dorsal and ventral stomata of the leaf and its serrate margins, the dentate walls of the ray-tracheids have become fixed and constant. But a new form of seed-wing appears, with a thickened blade, assuming such proportions in P. Sabiniana and its two allies that these three constitute a distinct group, remarkable also for the size of its cones.
Here also appear a new form of fruit, the oblique cone, and a new method of dissemination, the serotinous cone. Associated with the latter are the persistent cone and the multinodal spring-shoot. These characters do not develop in such perfect sequence and regularity that they can be employed for grouping the species without forcing some of them into unnatural association. The oblique cone first appears sporadically here and there and without obvious reason. The persistent cone, the first stage of the serotinous cone, is equally sporadic in the earlier stages of evolution. The same may be said of the multinodal shoot.
Nevertheless these characters show an obvious progression toward a definite goal, where they are all united in a small group of species remarkable for the form and texture of their cones, for a peculiar seed-release and for the vigor and rapidity of their growth. It is possible, with the assistance of other characters, to segregate these species in three groups in which the affinities are respected and the general trend of their evolution is preserved.
The first group, the Lariciones, contains species with large ray-pits, cones dehiscent at maturity, and uninodal spring-shoots. They are, with two exceptions, P. resinosa and P. tropicalis, Old World species.
The second group, the Australes, contains species with small ray-pits, cones dehiscent at maturity and spring-shoots gradually changing, among the species, from a uninodal to a multinodal form. They are, without exception, species of the New World.
The third group, the Insignes, contains the serotinous species. The ray-pits are small and the spring-shoots are, with two exceptions, multinodal. With two exceptions, P. halepensis and P. pinaster, they are New World species.
These three groups, being the progressive sequence of a lineal evolution, are not absolutely circumscribed, but are more or less connected through a few intermediate species of each group. The systematic position of these intermediate species is determined by their obvious affinities. It cannot be expected that the variations, which take an important part in the evolution of the species, progress with equal step or in perfect correlation with each other.
As to specific determinations, a little experience in the field discloses an amount of variation in species that does not always appear in the descriptions of authors; and species that are under the closest scrutiny of botanists, foresters or horticulturalists, attest by their multiple synonymy their wide variation. The possibilities of variation are indefinite and, with adaptable Pines, the range of variation is somewhat proportionate to change of climate. In mountainous countries, where there are warm sheltered valleys with rich soil below cold barren ledges, the most variable Pines are found. The western species of North America, for instance, are much more variable than the eastern species, while in Mexico, a tropical country with snow-capped mountains, the variation is greatest.
Therefore in the limitation of species undue importance should not be given to characters responsive to environment, such as the dimensions of leaf or cone, the number of leaves in the fascicle, etc. Moreover, there are familiar examples (P. sylvestris, etc.) that show the possibility of wide differences in the cone of the same species.
In the following classification species only are considered without attempting to determine varietal or other subspecific forms. But varieties are often mentioned as one of the factors illustrating the scope of species. Synonymy serves a like purpose, but synonyms not conveying useful information are omitted, Roezl's list of Mexican species, for instance, and variations in the orthography of specific names.
PINUS
- 1755 Pinus Duhamel, Traité des Arbres, ii. 121.
- 1790 Apinus Necker, Elem. Bot. iii. 269.
- 1852 Cembra Opiz, Seznam, 27.
- 1854 Strobus Opiz, Lotos, iv. 94.
- 1903 Caryopitys Small, Fl. Southeast. U. S. 29.
Leaves and shoots dimorphous, primary leaves on long shoots, secondary leaves on dwarf shoots. Flowers diclinous, the pistillate taking the place of long shoots, the staminate taking the place of dwarf shoots. Growth of wood and fruit emanating from the nodes; buds, branchlets and cones, therefore, in verticillate association. Leaves and staminate flowers in internodal position, the primary leaves along the whole length of the internode, subtending secondary leaf-fascicles on the apical, staminate flowers on the basal part. Buds compounded of minute buds in the axils of bud-scales, becoming the bracts of the spring-shoot. Branchlets of one or more internodes, each internode in three parts—a length without leaves, a length bearing leaves and a node of buds. Cone requiring two, rarely three years to mature, displaying its annual growths by distinct areas on each scale. Seeds wingless or winged, edible and nutritious.
The Pines are confined to the northern hemisphere, but grow in all climates and under all conditions of soil, temperature and humidity where trees can grow. Some of the species are of very restricted range, but others are adaptable and can cover wide areas. The sixty-six species are distributed as follows—
Eastern Hemisphere, 23.
- 1 exclusively African (Canary Islands).
- 2 exclusively European.
- 3 about the Mediterranean Basin.
- 2 common to Europe and northern Asia.
- 14 exclusively Asiatic.
Western Hemisphere, 43.
- 28 in western North America, of which 12 are confined to Mexico and Central America.
- 15 in eastern North America, of which 2 are exclusively West Indian.
The two sections of the genus correspond with those of Koehne (Deutsch. Dendrol. 28 [1893]) and his two names, Haploxylon and Diploxylon, are adopted here, together with his two subsections of Haploxylon, Cembra and Paracembra.
Of the two subsections of Diploxylon, Pinaster has been employed by Endlicher (Syn. Conif. 166 [1847]) and later authors for smaller or larger groups of Hard Pines. The subsection Parapinaster is now proposed.
The names of groups, Cembrae, Strobi, Cembroides, Gerardianae, Balfourianae, Pineae, Lariciones and Australes, are taken from Engelmann's Revision of the Genus Pinus (Trans. Acad. Sci. St. Louis, iv. 175-178 [1880]). The remainder, Flexiles, Leiophyllae, Longifoliae, Insignes and Macrocarpae, are here proposed.
In order to bring the illustrations within the limits of the page the dimensions of cone and leaf, as shown on the plates, are a little smaller than life. In plates X and XXV the reproductions of the cones are reduced to 2/5 life-size.
SECTIONS, SUBSECTIONS, AND GROUPS
| Bases of the fascicle-bracts non-decurrent | A—HAPLOXYLON |
| Umbo of the cone-scale terminal | a—Cembra |
| Seeds wingless. | |
| Cones indehiscent | I. Cembrae |
| Cones dehiscent | II. Flexiles |
| Seed with an adnate wing | III. Strobi |
| Umbo of the cone-scale dorsal | b—Paracembra |
| Seeds wingless | IV. Cembroides |
| Seed-wing short, ineffective | V. Gerardianae |
| Seed-wing long, effective | VI. Balfourianae |
| Bases of the fascicle-bracts decurrent | B—DIPLOXYLON |
| Fascicle-sheath or seed of Haploxylon | c—Parapinaster |
| Fascicle-sheath deciduous | VII. Leiophyllae |
| Fascicle-sheath persistent. | |
| Seed-wing of the Strobi | VIII. Longifoliae |
| Seed-wing of the Gerardianae | IX. Pineae |
| Fascicle-sheath persistent, seed-wing articulate, effective | d—Pinaster |
| Base of wing-blade thin or slightly thickened. | |
| Cones dehiscent at maturity. | |
| Pits of ray-cells large | X. Lariciones |
| Pits of ray-cells small | XI. Australes |
| Cones serotinous, pits of ray-cells small | XII. Insignes |
| Base of wing-blade very thick | XIII. Macrocarpae |
HAPLOXYLON
Bases of the bracts subtending leaf-fascicles not decurrent. Staminate flowers not sufficiently developed in the bud to be apparent. Spring-shoots uninodal. Fibro-vascular bundle of the leaf single. Cone symmetrical, of relatively fewer larger scales, its tissues softer. Bark-formation late, the trunks of young trees smooth. Wood soft and with little resin, of uniform color and with relatively obscure definition of the annual rings. Tracheids of the medullary rays with smooth walls.
All the species of this section, except P. Nelsonii, have deciduous fascicle-sheaths. There are but two species of Diploxylon with deciduous sheaths, P. leiophylla and P. Lumholtzii, both of them easily recognized. The deciduous sheath, therefore, is an obvious and useful means for recognizing the Soft Pines. On the characters of the fruit and the wood Haploxylon can be divided into two subsections.
| a. Cembra | Umbo of the cone-scale terminal. |
| b. Paracembra | Umbo of the cone-scale dorsal. |
Cembra
Umbo of the cone-scale terminal. Scales of the conelet unarmed. Leaves in fascicles of 5, the sheath deciduous, the two dermal tissues distinct, the hypoderm-cells uniform. Pits of the cells of the wood-rays large.
| Seeds wingless. | |
| Cones indehiscent | I. Cembrae. |
| Cones dehiscent | II. Flexiles. |
| Seeds with an adnate wing | III. Strobi. |
I. CEMBRAE
Seeds wingless. Cones indehiscent, deciduous at maturity.
In this group of species there is no segregation of sclerenchyma into an effective tissue. The cones are inert under hygrometric changes and may always be recognized in herbaria by their persistent occlusion and soft tissues. The seeds are released only by the disintegration of the fallen cone. There is, however, a vicarious dissemination by predatory crows (genus Nucifraga) and rodents.
| Leaves serrulate, their stomata ventral only. | |
| Cones relatively larger, the apophyses protuberant | 1. koraiensis. |
| Cones relatively smaller, the apophyses appressed | 2. cembra. |
| Leaves entire, their stomata ventral and dorsal | 3. albicaulis. |
1. PINUS KORAIENSIS
- 1784 P. strobus Thunberg, Fl. Jap. 275 (not Linnaeus).
- 1842 P. koraiensis Siebold & Zuccarini, Fl. Jap. ii. 38.
- 1857 P. mandschurica Ruprecht in Bull. Acad. Sci. St. Pétersb. xv. 382.
Spring-shoots more or less densely tomentose. Leaves from 8 to 12 cm. long, serrulate, stomata ventral only, resin-ducts medial and confined to the angles. Conelets large, subterminal, or on young trees often pseudolateral. Cones indehiscent, from 9 to 14 cm. long, short-pedunculate, ovoid-conical or subcylindrical; apophyses dull pale nut-brown, rugose, shrinking much in drying and exposing the seeds, prolonged and tapering to a more or less reflexed tip, the umbo inconspicuous; seeds large, wingless, the spermoderm entire.
A species of the mountains of northeastern Asia with valuable wood and large edible nuts; hardy and often cultivated in cool-temperate climates.
The P. koraiensis of Beissner (in Nuov. Giorn. Bot. Ital. n. ser. iv. 184) and of Masters (in Gard. Chron. ser. 3, xxxiii. 34, ff.) are P. Armandi and have led to an erroneous extension of the range of this species into Shensi and Hupeh. In the original description of the species the authors call attention to an error in the plate, where a cone of another species has been substituted.
P. koraiensis resembles P. cembra in leaf and branchlet but not in the cone. It is often confused with P. Armandi, but can easily be distinguished by its tomentose branchlets, indehiscent cone and peculiar seed. The two species, moreover, do not always agree in the position of the foliar resin-ducts.
Fig. 85, Cone and seed. Fig. 86, Leaf-fascicle and magnified leaf-section.
2. PINUS CEMBRA
- 1753 P. cembra Linnaeus, Sp. Pl. 1000.
- 1778 P. montana Lamarck, Fl. Franç. iii. 651 (not Miller).
- 1858 P. pumila Regel in Index Sem. Hort. Petrop. 23.
- 1884 P. mandschurica Lawson, Pinet. Brit. i. 61, ff. (not Ruprecht).
- 1906 P. sibirica Mayr, Fremdl. Wald- & Parkb. 388.
- 1913 P. coronans Litvinof in Trav. Mus. Bot. Acad. St. Pétersb. xi. 23, f.
Spring-shoots densely tomentose. Leaves from 5 to 12 cm. long, serrulate; stomata ventral only; resin-ducts medial or, in the dwarf form, often external. Conelets short-pedunculate, purple during their second season. Cone from 5 to 8 cm. long, ovate or subglobose, subsessile; apophyses dull nut-brown, thick, slightly convex, the margin often a little reflexed, the umbo inconspicuous; seeds wingless, large, the dorsal spermoderm adnate partly to the nut, partly to the cone-scale, the ventral spermoderm wanting.
The Swiss Stone Pine attains a height of 15 or 25 metres and occupies two distinct areas, the Alps, from Savoy to the Carpathians at high altitudes, and the plains and mountain-slopes throughout the vast area from northeastern Russia through Siberia. Beyond the Lena and Lake Baikal it becomes a dwarf (var. pumila) with its eastern limit in northern Nippon and in Kamchatka. It is successfully cultivated in the cool-temperate climates of Europe and America. The wood is of even, close grain, peculiarly adapted to carving. The nuts are gathered for food and confections, but are destroyed in great numbers by squirrels, mice and a jay-like crow, the European Nutcracker. It is generally conceded, however, that these enemies assist in dissemination.
Fig. 87, Cone, seed and magnified leaf-section. Fig. 88, Tree at Arolla, Switzerland. Fig. 89, Cone, leaf-fascicle and magnified leaf-section of var. pumila.
3. PINUS ALBICAULIS
- 1853 P. flexilis Balfour in Bot. Exped. Oregon, 1, f. (not James).
- 1857 P. cembroides Newberry in Pacif. R. R. Rep. vi-3, 44, f. (not Zuccarini).
- 1863 P. albicaulis Engelmann in Trans. Acad. Sci. St. Louis, ii. 209.
- 1867 P. shasta Carrière, Trait. Conif. ed. 2, 390.
Spring-shoots glabrous or pubescent. Branchlets pliant and tough. Leaves from 4 to 7 cm. long, entire, stout, persistent for several years; stomata dorsal and ventral; resin-ducts external. Conelets short-pedunculate, dark purple during the second season, their scales often tapering to an acute apex. Cones from 5 to 7 cm. long, subsessile, oval or subglobose; apophyses nut-brown or fulvous brown, dull or slightly lustrous, very thick, the under surface conspicuous, meeting the upper surface in an acute margin, and terminated by a salient, often acute umbo; seed wingless, the testa bare of spermoderm.
This species ranges from British Columbia through Washington and Oregon, over the mountains of northern California and the Sierras as far south as Mt. Whitney, and, on the Rocky Mountains, through Idaho and Montana to northern Wyoming. It is found at the timber-line of many stations and forms, in exposed situations, flat table-like masses close to the ground. It is a species of no economical importance and is too inaccessible for the profitable gathering of its large nuts, which are devoured in quantity by squirrels and by Clark's crow, a bird of the same genus with the pinivorous Nutcracker of Europe.
P. albicaulis is distinguished from its allies by its entire leaves with both dorsal and ventral stomata, from P. flexilis by its indehiscent cone, and from all of these species by its seed without membranous cover or rudimentary wing. It was united with P. flexilis by Parlatore and Gordon, and, later, was referred to that species as a varietal form by Engelmann (in Brewer & Watson, Bot. Calif. ii. 124). Parrish's P. albicaulis (in Zoe, iv. 350), extending its range to the mountains of southern California, proves to be P. flexilis (Jepson, Silva Calif. 74).
Fig. 90, Two cones and seed. Fig. 91, Leaf-fascicle. Fig. 92, Magnified leaf-section.
II. FLEXILES
Seeds wingless, the spermoderm forming a narrow border with a rudimentary prolongation. Cones dehiscent at maturity.
The dehiscent cone distinguishes this group from the Cembrae. Therefore confusion of P. koraiensis with P. Armandi, or P. albicaulis with P. flexilis should be impossible. The peculiar seed is found again only in the northern variety of P. ayacahuite.
| Leaves usually entire, the stomata dorsal and ventral | 4. flexilis. |
| Leaves serrulate, the stomata ventral only | 5. Armandi. |
4. PINUS FLEXILIS
- 1823 P. flexilis James in Long's Exped. ii. 34.
- 1882 P. reflexa Engelmann in Bot. Gaz. vii. 4.
- 1897 P. strobiformis Sargent, Silva N. Am. xi. 33, tt. 544, 545 (not Engelmann).
Spring-shoots pubescent; branchlets very tough and pliant. Leaves from 3 to 9 cm. long, entire, or serrulate in the southern variety, persistent for five or six years; stomata dorsal and ventral or, in the south, sometimes ventral only; resin-ducts external. Cones from 6 to 25 cm. long, ovate or subcylindrical, short-pedunculate; apophyses pale tawny yellow, or yellow ochre, lustrous, often prolonged and more or less reflexed, thick, the margin together with the umbo raised above the surface of the cone.
This species grows on the Rocky Mountains from Alberta in the Dominion of Canada to Chihuahua in northern Mexico and ranges westward to the eastern slope of the Sierras and to the southern mountains of California. The wood, where accessible, is manufactured into lumber. It may be seen in the Arnold Arboretum and in the Royal Gardens at Kew.
P. flexilis is recognized by its lustrous yellow cones. This and the constantly external ducts of its usually entire leaves distinguish it from P. Armandi. From P. albicaulis, with similar leaves, it differs by its dehiscent cone. At one extreme the cone of P. flexilis is not unlike that of P. albicaulis, at the other extreme it approaches the characteristic cone of P. ayacahuite, with prolonged reflexed scales. Hence the confusion of P. albicaulis with P. flexilis (Murray, Parlatore and others) and of P. flexilis with Engelmann's P. strobiformis. Sargent's P. strobiformis, illustrated in the Silva of North America, is the form of this species known as var. reflexa of Engelmann.
Fig. 93, Two cones and seed. Fig. 94, Leaf-fascicle. Fig. 95, Magnified leaf-section.
5. PINUS ARMANDI
- 1884 P. Armandi Franchet in Nouv. Arch. Mus. Paris, sér. 2, vii. 95, 96, t. 12.
- 1898 P. scipioniformis Masters in Bull. Herb. Boiss. vi. 270.
- 1903 P. koraiensis Masters in Gard. Chron. ser. 3, xxxiii. 34, ff. 18, 19 (not Siebold & Zuccarini).
- 1908 P. Mastersiana Hayata in Gard. Chron. ser. 3, xliii, 194.
Spring-shoots glabrous; branches and most of the trunk covered with a smooth gray cortex. Leaves from 8 to 15 cm. long, serrulate; stomata ventral only; resin-ducts external, external and medial, or medial, all three conditions sometimes occurring in leaves of the same branchlet. Cones from 6 to 20 cm. in length, pendent on peduncles of various lengths, the peduncle often remaining on the tree after the fall of the cone; apophyses fulvous brown, dull or sublustrous, the margin rounded or tapering to an acute apex, sometimes a little prolonged and reflexed, the umbo inconspicuous.
A tree of the mountains of central, southern and western China with an outlying station on the Island of Formosa. Recently planted in Europe and America, it has so far proved hardy. The nuts are gathered for food and some use is made of the wood.
The glabrous shoots of P. Armandi distinguish it from P. flexilis and P. koraiensis. From the latter it is also distinct in its dehiscent cone and in its seed. The section of its leaf, with dorsal ducts often in two positions, is peculiar to this species among Soft Pines.
Fig. 96, Two cones and seed. Fig. 97, Leaf-fascicle. Figs. 98, 99, Magnified sections of three leaves.
III. STROBI
Seed with a long effective wing adnate to the nut.
The base of the seed-wing corresponds to the marginal spermoderm of the Flexiles but is prolonged into an effective adnate wing. This form of wing appears again in the species Balfouriana and in the group Longifoliae.
| Cones very long, usually exceeding 25 cm. | |
| Cone-scales prolonged and reflexed | 6. ayacahuite. |
| Cone-scales appressed | 7. Lambertiana. |
| Cones less than 25 cm. long. | |
| Cone-scales prominently convex. | |
| Leaves less than 7 cm. long | 8. parviflora. |
| Leaves 9-12 cm. long | 9. peuce. |
| Leaves 12-18 cm. long | 10. excelsa. |
| Cone-scales thin, conforming to the surface of the cone. | |
| Cone relatively longer, its phyllotaxis 8/21 | 11. monticola. |
| Cone relatively shorter, its phyllotaxis 5/13 | 12. strobus. |
6. PINUS AYACAHUITE
- 1838 P. ayacahuite Ehrenberg in Linnaea, xii. 492.
- 1848 P. strobiformis Engelmann in Wislizenus, Tour Mex. 102.
- 1857 P. Veitchii Roezl, Cat. Graines Conif. Mex. 32.
- 1858 P. Bonapartea Roezl in Gard. Chron. 358.
- 1858 P. Loudoniana Gordon, Pinet. 230.
Spring-shoots glabrous or pubescent. Leaves from 10 to 20 cm. long, serrulate, their stomata ventral only, their resin-ducts external, often numerous. Cones from 25 to 45 cm. long, pendent on long stalks, subcylindrical or tapering, often curved; apophyses pale nut-brown, dull or sublustrous, varying much in thickness, prolonged in various degrees, the prolongations patulous, reflexed, recurved or revolute; seeds of the southern typical form with a long wing, the wing diminishing and the nut increasing in relative size northward.
The White Pine of Mexico and Guatemala grows on mountain-slopes and at the head of ravines. It is not very hardy in cultivation except in the milder parts of Great Britain and in northern Italy, where the forms of central and northern Mexico have been very successful. The species is best recognized by the prolonged apophyses of its large cone.
The variations in the size of the cone and in the prolongations of its scales are many, but of far more significance is the remarkable variation of the seed-wing, which is long in the southern part of the range, short and broad in central Mexico, and rudimentary, like the seed of P. flexilis, in the north. This makes it possible to establish two well defined varieties—Veitchii and brachyptera. The three forms of the species present a gradation from the long effective wing of the Strobi to the rudimentary form of the Flexiles. Many of the seed-wings of the var. Veitchii correspond, in their short broad form and opaque coloring, with the characteristic wing of P. Lambertiana.
Fig. 103, Cone and cone-scale of var. Veitchii. Fig. 104, Cone and seed of var. brachyptera. Fig. 105, Cone-scale of the typical form. Figs. 106, 107, Leaf-fascicles and magnified leaf-sections.
7. PINUS LAMBERTIANA
- 1827 P. Lambertiana Douglas in Trans. Linn. Soc. xv. 497.
Spring-shoots pubescent. Leaves from 7 to 10 cm. long, serrulate; stomata dorsal and ventral; resin-ducts external or with one or two ventral medial ducts. Cones from 30 to 50 cm. long, pendent, subcylindrical, tapering to a rounded apex; apophyses pale nut-brown, thick, a narrow border of the under surface showing on the closed cone, the margin rounded or tapering to a blunt slightly reflexed tip; seed with a large nut and a broad short opaque wing.
The Sugar Pine is the tallest of the genus and attains a height of 50 or 60 metres. It grows on mountain slopes and the sides of ravines. Its southern limit is in Lower California on the plateau of San Pedro Martir, its northern limit is in western Oregon. The wood is valuable, its nuts are eaten by native Indians, and the sweet exudation, which gives the tree its popular name, is a manna-like substance of some officinal value. P. Lambertiana is recognized by its long cone and by the constant dorsal stomata of its leaves.
Fig. 100, Cone and seed. Fig. 101, Conelet. Fig. 102, Leaf-fascicle and magnified leaf-section.
8. PINUS PARVIFLORA
- 1784 P. cembra Thunberg, Fl. Jap. 274. (not Linnaeus).
- 1842 P. parviflora Siebold and Zuccarini, Fl. Jap. ii. 27, t. 115.
- 1890 P. pentaphylla Mayr, Mon. Abiet. Jap. 78, 94, t. 6.
- 1908 P. morrisonicola Hayata in Gard. Chron. ser. 3, xliii. 194.
- 1908 P. formosana Hayata in Jour. Linn. Soc. xxxviii. 297, t. 22.
Spring-shoots pubescent or glabrous; branches becoming studded with prominent resin-cells of the cortex. Leaves from 3 to 8 cm. long, slender, serrulate; stomata ventral only; resin-ducts external and dorsal. Cones subsessile, often persistent, from 5 to 10 cm. long, patulous or horizontal, short-ovate, or elongate and slightly conical; apophyses nut-brown, abruptly convex near the apex, or irregularly warped, varying much in size, the umbo confluent with the thin margin of the scale and resting on the apophysis beneath; seeds with a large nut and a short broad wing, often temporarily adherent to the cone-scale and breaking apart at the fall of the nut.
A tree of the mountains of Japan and Formosa, cultivated extensively. It is recognized by its very short quinate leaves and by its nearly sessile cones. The frequent but not invariable retention of the seed-wing in the cone is due to adhesion. Many seeds fall with their wings intact, others break away from the wing which, after a while, loosens and also falls.
Figs. 114, 115, Three cones and seed. Fig. 116, Leaf-fascicle and magnified leaf-section.
9. PINUS PEUCE
- 1844 P. peuce Grisebach, Spicil. Fl. Rumel. ii. 349.
- 1865 P. excelsa Hooker in Jour. Linn. Soc. viii. 145. (not Wallich).
Spring-shoots glabrous. Leaves from 7 to 10 cm. long, erect, serrulate; stomata ventral only; resin-ducts external. Connective of pollen-sacs small and narrow. Cones deciduous, from 8 to 15 cm. long, subcylindrical, often curved, the peduncle short; apophyses tawny yellow, prominently and abruptly convex, the umbo against the scale beneath; seed-wing long.
A tree of the Balkan Mountains, very hardy and bearing abundant fruit in the gardens of both hemispheres. The cone resembles that of P. excelsa, but is prevalently much shorter and with a relatively shorter peduncle. Its leaves are also much shorter and are always erect. A curious difference is found in the connectives of the pollen-sacs, small in peuce (fig. 113), large in excelsa (fig. 110). The convexity of its apophyses distinguishes the cone from those of P. monticola and P. strobus. Beissner followed Hooker and named this species excelsa, var. peuce, in the first edition of his Handbuch (1891), but in the second edition he restored the Balkan Pine to specific standing.
Fig. 111, Cone and seed. Fig. 112, Leaf-fascicle and magnified leaf-section. Fig. 113, Pollen-sacs and connective magnified.
10. PINUS EXCELSA
- 1824 P. excelsa Wallich ex Lambert, Gen. Pin. ii, 5, t. 3.
- 1845 P. nepalensis De Chambray, Arbr. Résin. 342.
- 1854 P. Griffithii McClelland in Griffith, Notul. Pl. Asiat. iv, 17; Icon. Pl. Asiat. t. 365.
Spring-shoots glabrous. Leaves from 10 to 18 cm. long, drooping, serrulate; stomata ventral only; resin-ducts external but often with a medial ventral duct. Connective of the pollen-sacs large. Cones from 15 to 25 cm. long, narrow-cylindrical; apophyses tawny yellow or pale fulvous brown, prominently convex, the umbo against the apophysis beneath; seeds with a long wing.
A tree with gray-green drooping foliage, found, with some interruptions, along the Himalayas. It furnishes resin, tar and wood of considerable value. It is cultivated in all temperate climates and is a familiar tree of American and European gardens. Madden states that the foliage of P. excelsa is sometimes erect and is occasionally bright green. Such variations are often met in other species of Pinus. Usually the drooping gray-green foliage and the peculiar cone are sufficient for the recognition of this species. The not infrequent presence of a medial duct and the large connective are valuable aids for identifying it.
Fig. 108, Cone and seed. Fig. 109, Leaf-fascicle and magnified section of two leaves. Fig. 110, Pollen-sacs and connective magnified.
11. PINUS MONTICOLA
- 1837 P. monticola Douglas ex Lambert, Gen. Pin. iii. t.
- 1884 P. porphyrocarpa Lawson, Pinet. Brit. i, 83, ff.
Spring-shouts pubescent. Leaves from 4 to 10 cm. long, serrulate; stomata ventral or rarely with a few dorsal stomata; resin-ducts external. Cones from 10 to 25 cm. long, cylindrical or tapering, sometimes curved; apophyses brown-ochre or fulvous brown, thin, smooth, conforming to the surface of the cone, the apex sometimes slightly prolonged and reflexed, the umbo not quite touching the surface of the scale below.
The western White Pine grows in southern British Columbia and on Vancouver Island, on the Rocky Mountains of Montana and Idaho, in Washington, on the Blue Mountains, Cascades and Coast Range of Oregon, across northern California and along the Sierras to the mountains of southern California. Where it is abundant and accessible it furnishes valuable timber. It is hardy in New England and in northern and central Europe.
It differs from P. strobus in the higher phyllotaxis of its cone, an obvious difference that may be seen by comparing cones of the two species of the same length (figs. 117, 119), the number of scales on the cone of P. monticola being much greater than that on the cone of P. strobus. Nuttall (Sylva, iii, 118) followed Hooker in considering it to be a variety of P. strobus.
Fig. 117, Cone and cone-scale. Fig. 118, Leaf-fascicle and magnified leaf-section.
12. PINUS STROBUS
- 1753 P. strobus Linnaeus, Sp. Pl. 1001.
- 1855 P. nivea Booth ex Carrière, Trait. Conif. 305.
- 1862 P. alba-canadensis Provancher, Fl. Canad. ii. 554.
- 1903 Strobus strobus Small, Fl. Southeast. U. S. 29.
Spring-shoots pubescent. Leaves from 6 to 14 cm. long, serrulate; stomata ventral only; resin-ducts external. Cones from 8 to 24 cm. long, narrow cylindrical, sometimes curved; apophyses fulvous brown, or rufous brown, thin, the smooth or slightly rugose surface conforming to the general surface of the cone; seed with a long wing.
A valuable timber-tree of singular beauty and rapid growth. The northern limit of its range extends from Newfoundland to Manitoba; it grows throughout the northern states from Minnesota to the Atlantic, and, south of Pennsylvania, along the Appalachians to northern Georgia. Its tractable and reliable wood, its adaptability to various soils and climates, its early maturity and stately habit, recommend it to the forester and gardener.
Mature trees of P. strobus tower above the evergreens associated with it. It is also recognized by the color and horizontal massing of its foliage. The cone, when closed, is very narrow; its thin flat scales distinguish it from the cone of P. peuce, and its phyllotaxis from the cone of P. monticola. To illustrate the possibilities of variation in the size of Pine cones, I once collected several in Tamworth, N. H., on the estate of Mr. Augustus Hemenway, on the same slope and within an area of one square kilometre. These cones varied in length from 6 to 24 cm., with all intermediate sizes. Also on each tree were cones of various lengths, but the longest were confined to two or three trees among the several hundred examined. Dimensions of leaves also varied with individual trees; not infrequently the leaves of a tree were twice the length of those of an adjacent tree. Such variations appear in many species and in many localities.
Fig. 119, Two cones. Fig. 120, Leaf-fascicle. Fig. 121, Magnified leaf-section. Fig. 122, Conelets. Fig. 123, A cultivated tree in Massachusetts.
Paracembra
Umbo of the cone-scale dorsal. Scales of the conelet mucronate or aristate. Epiderm and hypoderm of the leaf similar, appearing as a single tissue; resin-ducts external. Pits of the ray-cells small.
The wood of this subsection differs from that of other species, except that of P. pinea, in the Picea-like characters of the medullary rays—tracheids with smooth walls combined with the thick walls and small pits of the ray-cells. On the character of the seeds the species may be divided into three groups.
| Seeds wingless | IV. Cembroides. |
| Seeds with a short, ineffective, articulate wing | V. Gerardianae. |
| Seeds with a long and effective wing | VI. Balfourianae. |
IV. CEMBROIDES
Seeds wingless, the nut large, wholly or partly bare of membranous cover. Cones varying from yellow-ochre to deep red-orange in color.