1784 P. strobus Thunberg, Fl. j.a.p. 275 (not Linnaeus).

1842 P. koraiensis Siebold & Zuccarini, Fl. j.a.p. ii. 38.

1857 P. mandschurica Ruprecht in Bull. Acad. Sci. St. Petersb. 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, x.x.xiii. 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 subst.i.tuted.

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.

Plate VIII.

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. Franc. 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. Petersb.

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 alt.i.tudes, 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 a.s.sist in dissemination.

Plate VIII.

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 Carriere, Trait. Conif. ed. 2, 390.

Spring-shoots glabrous or p.u.b.escent. 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 l.u.s.trous, 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 ma.s.ses 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 quant.i.ty 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).

Plate VIII.

Fig. 90, Two cones and seed. Fig. 91, Leaf-fascicle. Fig. 92, Magnified leaf-section.

[Ill.u.s.tration: PLATE VIII. P. KORAIENSIS (85, 86), CEMBRA (87-89), ALBICAULIS (90-92)]

=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 p.u.b.escent; 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, l.u.s.trous, 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 l.u.s.trous 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, ill.u.s.trated in the Silva of North America, is the form of this species known as var. reflexa of Engelmann.

Plate IX.

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, ser. 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, x.x.xiii. 34, ff. 18, 19 (not Siebold & Zuccarini).

1908 P. Mastersiana Hayata in Gard. Chron. ser. 3, xliii, 194.