The Genus Pinus Part 9

Fig. 130, Cone, cone-scale and seed. Fig. 131, Open cone. Fig. 132, Branchlet with leaves and magnified leaf-section.

14. PINUS PINCEANA

1846 P. cembroides Gordon in Jour. Hort. Soc. Lond. i. 236, f.

(not Zuccarini).

1858 P. Pinceana Gordon, Pinet. 204.

1882 P. latisquama Engelmann in Gard. Chron. ser. 2, xviii. 712.

f. 125 (as to cone only).

Spring-shoots slender, pruinose. Leaves in fascicles of three, the sheath revolute at the base, then deciduous; stomata ventral, or ventral and dorsal; resin-ducts external. Scales of the conelet minutely mucronate. Cones from 6 to 9 cm. long, cylindrical, pendent on long peduncles; apophyses l.u.s.trous ochre-yellow, elevated in the centre, the umbo usually retaining the small p.r.i.c.kle; seed large, bearing on its dorsal surface remnants of the spermoderm.

A small bushy tree with long slender branchlets, clear gray cortex, persistently smooth except on the lower part of the trunk, and glaucous-green foliage. It grows along water-courses, dry in autumn and winter, from southern Coahuila to central Hidalgo, and is a.s.sociated with P. cembroides, from which it may be distinguished by its longer leaves and much longer cylindrical cone.

Plate XIII.

Fig. 127, Cone, cone-scale and seed. Fig. 128, Branchlet with leaves. Fig. 129, Magnified leaf-section.

15. PINUS NELSONII

1904 P. Nelsonii Shaw in Gard. Chron. ser. 3, x.x.xvi. 122, f. 49.

Spring-shoots slender, pruinose; branchlets very pliant and tough, summer-shoots abundant. Leaves with a persistent sheath, from 6 to 9 cm.

long, united in threes along a portion of their ventral surface into pseudomonophyllous fascicles, serrulate on the two margins of the dorsal surface, entire on the ventral margin; stomata dorsal and with one row along the free portion of each ventral face. Conelets usually, if not always, pseudolateral by reason of the summer growth of the branchlets, and attaining in their first season an unusually large size. Cones from 6 to 12 cm. long, on very long stout and curved peduncles, cylindrical, deciduous by an articulation between the cone and its peduncle, leaving the latter for several years on the tree; apophyses dark l.u.s.trous orange-red, rugose, elevated along a sharp transverse keel, the umbo obscurely defined, the mucro usually broken away; nuts large, flaxen yellow, the spermoderm adnate to the cone-scale.

A small bushy tree with long pliant branches, clear gray cortex all over the limbs and trunk, and spa.r.s.e gray-green foliage. It grows, together with P. cembroides, on the lower slopes of the northeastern Sierras of Mexico, near the boundary between the states of Tamaulipas and Nuevo Leon. It is apparently confined to a small area near the lat.i.tude of the city of Victoria, the capital of Tamaulipas, where its nuts are often exposed for sale.

In many characters this species is unique. It can be recognized at once by the connate leaves that form the fascicle or by the remarkable stout curved peduncle of its cone. Such seeds as I have seen differ from those of P. cembroides by a reddish area at one end, but this can be seen with fresh seeds only.

Plate XIII.

Fig. 124, Cone, cone scale and seed. Fig. 125, Branchlet with leaves. Fig. 126, Magnified section of a leaf-fascicle.

[Ill.u.s.tration: PLATE XIII. P. NELSONII (124-126), PINCEANA (127-129), CEMBROIDES (130-132)]

=V. GERARDIANAE=

Seeds with a very short ineffective articulate wing. Leaves in fascicles of 3, serrulate, the sheath deciduous. Bark exfoliating in large scales, leaving parti-colored areas.

These Asiatic Nut Pines are alike in leaf and cortex as well as in the peculiar seed-wing. The last often remains in the cone after the nut falls. The mechanical nature of this adhesion is apparent in P.

Gerardiana, where the wing adheres not to its own, but to the adjacent scale. The two species are alike in their leaves but distinct in their cones and seeds.

Cones smaller, the nut short-ovate 16. Bungeana.

Cones larger, the nut long-cylindrical 17. Gerardiana.

16. PINUS BUNGEANA

1847 P. Bungeana Zuccarini ex Endlicher, Syn. Conif. 166.

Spring-shoots glabrous, summer-shoots common on fruiting branches of young trees. Leaves from 6 to 10 cm. long, serrulate; stomata dorsal and ventral; resin-ducts external. Conelets subterminal or often pseudolateral, their scales gradually narrowed into a spine. Cones from 5 to 7 cm. long, short-pedunculate, short-ovate; apophyses dull pale nut-brown, elevated along a transverse keel, the dark brown umbo forming a spine with a broad base; seeds with a short loosely attached wing, sometimes remaining in the cone when the short-ovate nut falls.

A tree cultivated about the temples of China and recently found by Wilson growing on the mountains of Hupeh. The earlier parti-colored bark changes to chalky white on old trunks, by which the tree is recognized from a great distance. The stem of the tree is often multiple by the vertical growth of some of the lower branches. It is very hardy and is cultivated in Europe and America, although these cultivated trees are not yet of sufficient age to show the remarkable white trunk.

Plate XIV.

Fig. 138, Cone and cone-scale with adhering wing. Fig. 139, Seed and wing. Fig. 140, Leaf-fascicle and magnified leaf-section. Fig. 141, Parti-colored bark. Fig. 142, Tree with white trunk.

17. PINUS GERARDIANA

1832 P. Gerardiana Wallich ex Lambert, Gen. Pin. ed. 8vo, ii. t. 79.

Spring-shoots glabrous. Leaves from 6 to 10 cm. long, serrulate; stomata dorsal and ventral; resin-ducts external. Scales of the conelet armed with a short spine. Cones from 9 to 15 cm. long, short-pedunculate, ovoid or oblong; apophyses fulvous brown, very thick, with a prominent reflexed or erect protuberance culminating in an umbo on which the spine is more or less persistent; nuts remarkably long, narrow, terete, the sh.e.l.l fragile, the short wing falling with the nut or adhering to the adjacent scale.

A tree of the northwestern Himalayas found on the borders of Cashmere and Thibet and in Kafiristan and north Afghanistan, and so highly prized for its nuts that it is rarely felled for its wood. It grows in dry regions and rarely attains a height of 20 metres. Attempts to cultivate this species, even in the milder parts of Great Britain, have generally failed.

The apophysis of the cone varies much in prominence (figs. 134, 135), but the peculiar seed is invariable and quite unlike that of any other Pine. The general color of the trunk at a distance is silver-gray.

Plate XIV.

Fig. 133, Cone. Fig. 134, Cone-scale with adhering seed-wing. Fig.

135, Cone-scale of flatter form. Fig. 136, Seed and wing. Fig. 137, Leaf-fascicle and magnified leaf-section.

[Ill.u.s.tration: PLATE XIV. P. GERARDIANA (133-137), BUNGEANA (138-142)]

=VI. BALFOURIANAE=

Seeds with long effective wings. Leaves entire, in fascicles of 5, the sheath deciduous.

The two species known as Foxtail Pines are alike in their short entire falcate leaves, persisting for many years and forming long dense foliage-ma.s.ses. They differ in the armature of their cones and in their seed-wings. The presence of both adnate and articulate wings in these closely related species suggests that these two forms of wing are not fundamentally distinct.

Cone-scales short-mucronate, the seed-wing adnate 18. Balfouriana.

Cone-scales long-aristate, the seed-wing articulate 19. aristata.

18. PINUS BALFOURIANA

1853 P. Balfouriana Balfour in Bot. Exp. Oregon, 1, f.

Spring-shoots somewhat p.u.b.erulent. Leaves from 2 to 4 cm. long, persistent for many years; stomata ventral only; resin-ducts external.

Scales of the conelet short-mucronate. Cones from 7 to 12 cm. long, tapering to a rounded apex, short-pedunculate; apophyses dark terracotta-brown, tumid, the umbo bearing a short rec.u.mbent p.r.i.c.kle; seed with a long adnate wing.

An alpine species growing often at the timber-limit. It is found in two distinct stations in California, on the northern Coast Range and on the southern Sierras. It is not often cultivated, but young plants may be seen in the Arnold Arboretum and in the Royal Gardens at Kew.

Plate XV.