The Genus Pinus Part 7

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 subl.u.s.trous, 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.

Plate IX.

Fig. 96, Two cones and seed. Fig. 97, Leaf-fascicle. Figs. 98, 99, Magnified sections of three leaves.

[Ill.u.s.tration: PLATE IX. P. FLEXILIS (93-95), ARMANDI (96-99)]

=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 p.u.b.escent. 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 subl.u.s.trous, 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 diminis.h.i.+ng 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.

Plate X. (leaves and cones much reduced).

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 p.u.b.escent. 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.

Plate X. (leaves and cone much reduced).

Fig. 100, Cone and seed. Fig. 101, Conelet. Fig. 102, Leaf-fascicle and magnified leaf-section.

[Ill.u.s.tration: PLATE X. P. LAMBERTIANA (100-102), AYACAHUITE (103-107)]

8. PINUS PARVIFLORA

1784 P. cembra Thunberg, Fl. j.a.p. 274. (not Linnaeus).

1842 P. parviflora Siebold and Zuccarini, Fl. j.a.p. ii. 27, t. 115.

1890 P. pentaphylla Mayr, Mon. Abiet. j.a.p. 78, 94, t. 6.

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

1908 P. formosana Hayata in Jour. Linn. Soc. x.x.xviii. 297, t. 22.

Spring-shoots p.u.b.escent 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 j.a.pan 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.

Plate XI.

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.

Plate XI.