d 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.

[Illustration: PLATE XIX. P. RESINOSA (170, 171), TROPICALIS (172-175)]

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