31. PINUS LUCHUENSIS
- 1894 P. luchuensis Mayr in Bot. Centralbl. lviii. 149, f.
Spring-shoots uninodal. Bark-formation late, the upper trunk covered with a smooth cortex. Leaves binate, from 12 to 16 cm. long, the epiderm thick, hypoderm of two or three rows of cells; resin-ducts medial or with an occasional external duct. Conelets mucronate toward the apex. Cones from 3 to 6 cm. long, ovate-conic, symmetrical; apophyses lustrous nut-brown, transversely carinate, the umbo unarmed.
This Pine is known to me through Mayr's description and a single dried specimen. The smooth cortex of young trees distinguishes it from all other east-Asiatic Hard Pines. Mayr includes under this species the Pine of Hong Kong. But in this he must be mistaken, for there is no species yet found in China that agrees with the description of P. luchuensis.
Fig. 191, Cone. Fig. 192, Leaf-fascicle and magnified leaf-section.
32. PINUS THUNBERGII
- 1784 P. sylvestris Thunberg, Fl. Jap. 274 (not Linnaeus).
- 1842 P. Massoniana Siebold & Zuccarini. Fl. Jap. ii. 24, t. 113 (not Lambert).
- 1868 P. Thunbergii Parlatore in DC. Prodr. xvi-2, 388.
Spring-shoots uninodal. Buds of leading-shoots white and conspicuous. Leaves binate, from 6 to 11 cm. long, the epiderm thick, hypoderm strong, resin-ducts medial. Conelets with short-mucronate scales. Cones from 4 to 6 cm. long, ovate or ovate-conic, symmetrical; apophyses nut-brown, flat or convex and transversely carinate, the prickle of the umbo more or less persistent.
The Black Pine of Japan has been cultivated for centuries, and by skillful Japanese gardeners has been trained into dwarf and other curious forms. It is hardy in cold-temperate climates. It is distinct from P. densiflora by the medial ducts of its leaf, from P. nigra by the fewer, larger, brown scales of its cone, and from P. resinosa by the armature of its conelet. It appears in most determinations of Chinese collections, but there is no Chinese Pine with the white buds and the medial leaf-ducts of this species.